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Car amplifiers FAQ

Answers to amp questions

Kenwood Excelon XR901-5

Kenwood Excelon XR901-5 five-channel amplifier — 60 watts RMS x 4 + 600 watts RMS x 1


» Where can I mount my amp?

» Why do I need to add an additional fuse at the battery? And how big a fuse do I need?

» Why fuse at the battery?

» How big should the fuse be?

» Do I need a separate fuse block too?

» What wiring do I need to hook up my amplifier? Does any of it come with the amp?

» What size power and ground wires do I need for my amplifier?

» What's this thin blue wire for?

» How much air space do I need around my amplifier?

» How do I hook up multiple amplifiers?

» My amplifier is hooked up, but it won't turn on. What's wrong?



» How much power do I need to get optimum performance from my car's sound system?

» What's the biggest amp I can hook up to my car's electrical system?

» Where should I ground my amp?

» What is a "high-current" amplifier?

» How much power do I need for my subwoofers?



» What should I know about my speakers' impedance?

» How can I drive a pair of speakers and a subwoofer with a single car audio amplifier?

» My new car amplifier is "2-ohm stable." How can I take advantage of that?



» What's the story on the different amplifier "classes"?

» What's the difference between "parallel" and "series" wiring?

» When should I use a mono amplifier instead of a multichannel amplifier?

» What are the benefits of hooking up 2 subwoofers to a mono amplifier? How would I wire them?

» What is "bridging" an amplifier?

» Are there any problems in bridging an amp?

» Can I bridge my mono amplifier?

» I'd like to add a power amplifier to my factory-installed car radio. What are my options?

» How do I fine-tune my amplifier's gain and bass boost settings?

» What is the difference between Peak Watts and RMS Watts?

Rockford Fosgate T400X2ad

Rockford Fosgate Power T400X2ad 2-channel amp — 200 watts RMS x 2

Q: Where can I mount my amp?

A: Since space is at a premium in most vehicles, it's important to find just the right spot to mount your amp. An amplifier needs some open air space around it to dissipate the heat that builds up as it works, otherwise it will overheat and shut down. Keeping that in mind, our two favorite locations are under a seat or in the trunk. Under-seat mounting is space-efficient and keeps the amp hidden from view. It also lets you run shorter cables from your receiver. A trunk-mounted amp requires longer power and signal cables, but is safely hidden and closer to rear speakers and your subwoofer.

Warning: removing your seat could deactivate your vehicle's SRS system.

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Q: My car audio amplifiers all came with fuses. Why do I need to add an additional fuse at the battery? And how big a fuse do I need?

A: The answers to most questions about fuses include the word "safety." While most car audio amplifiers do come with their own fuses, these fuses are designed to protect only the amps themselves. You need to install a fuse at the battery to protect the power wiring, your car, and yourself against fire, in the event of a short circuit. The next two answers cover this in greater detail.

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Q: Why fuse at the battery?

A: In the event of an electrical mishap, you do not want a live wire stretching throughout your vehicle. Installing a fuse of the proper amperage on your power cable protects your car and gear from the dangers of a short circuit. A short circuit occurs when a positive current-bearing wire makes contact with bare metal (like your car chassis). Because your entire car chassis can be considered "negative" or ground, you can think of a short circuit as positive touching negative. You definitely don't want this to happen, but if it does, a properly installed fuse will prevent a fire or other damage.

A fuse does its work by "blowing" and stopping the flow of current. A fuse is a lot easier and cheaper to replace than your car or your life. So, given the alternatives, "blowing a fuse" is a relatively good thing. You can optimize the protection your fuse provides by installing it as close to the battery as possible — that increases the length of the protected cable behind it. Eighteen inches from the battery is the maximum distance we recommend.

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Q: How big should the fuse be?

A: If you're installing just one amplifier, the fuse at the battery should simply match or slightly exceed the fuse rating of the amplifier itself. Some amps don't come with onboard fuses — you have to find their fuse ratings in their owner's manuals. If you're installing two or more amplifiers, just add their fuse ratings together and install a fuse rated roughly equal to this sum. Generally, it's better to go slightly higher than lower, but a margin of five amperes is acceptable.

Say you have three amplifiers, two with fuse ratings of 20 amps each and one with a fuse rating of 25 amps. In this case, you can safely go with either a 60 or 70 amp fuse. Of course, if your system is powerful enough to demand that you install a heavy duty fuse, it's important that your power and ground wire be of an appropriately heavy gauge as well.

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Q: Do I need a separate fuse block too?

A: A safe system will have the right fuses installed at each amplifier and also on the power cable by the battery. But if you've ever taken a peek at some multi-amp competition-style car audio systems, you may have noticed fuses at a third location — in a fuse block by the amps. Sure this hardware looks good, but is it necessary?

If your amplifiers have on-board fuses, you don't need another set. But if your amplifiers don't each have their own fuses, you definitely do need to fuse each amp's power line near the amp. Often this is done with a fused distribution block, so each amp gets its power line fused as it's split off from the main power cable. This makes it so that if one amp suffers a catastrophic short circuit, for instance, the damage will not spread to the other amps or your main power cable.

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Q: What wiring do I need to hook up my amplifier? Does any of it come with the amp?

A: Amplifiers generally do not include the wiring necessary to hook them up. However, we offer a number of amp wiring kits that can provide everything you need to send signal and power to your amp.

You need a thick power cable to run from your car battery's positive terminal, through the car's firewall, all the way to the amplifier. The required thickness (gauge) of the power wire is determined by the amp's manufacturer — you can look it up in the owner's manual or online. Be sure to install an in-line fuse or circuit breaker near the battery. Without one, an accidental short circuit could pose a fire hazard and damage your amp (not to mention your car).

You also need another length of the same gauge cable to serve as your ground wire. You won't need as long a ground wire because your grounding point should be close to the amplifier. The point on your car's chassis where you bolt the ground wire should be cleaned and scraped paint-free to ensure a tight electrical connection.

The last wire you need for powering the amp is a turn-on lead. It doesn't need to be as thick as the power and ground wires (18 gauge should be fine). It runs from the remote turn-on lead at the back of your receiver to the remote terminal on the amp. In the case of a factory system with no remote connection, you can tie into a switched 12-volt source, one that only comes on with the car, in the fuse box.

The audio signal travels from the back of your receiver to your amplifier through an RCA patch cable. Your patch cable should be long enough to reach the amp but not so long that it has a lot of slack and could become kinked over time. If you're using a factory receiver without RCA outputs, you can get your amp's input signal from the factory speaker wiring, either behind the radio or from the rear speaker leads. Many amplifiers have high- or speaker-level inputs to accommodate this kind of setup. Otherwise, you can use a line output converter to convert the speaker-level signal down to the preamp/RCA level your amp's input needs.

At the other end of the amp, you'll need speaker wire. Generally 12, 14, or 16 gauge wire should be sufficient. Keep in mind that current flows more easily through thicker wire. (The lower the gauge number, the thicker the wire.)

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Q: What size power and ground wires do I need for my amplifier?

A: Your car amplifier will draw a lot of current from your vehicle's electrical system, and therefore will need thick enough power wiring to ensure that the current flows freely, without resistance. This is important — otherwise, your amp can over-work, under-perform, or even overheat and shut down. For a single amplifier install, the required wire size has been specified by the amp's manufacturer and can be found in the owner's manual or online.

Wire Gauge Chart

Using thicker power and ground cables will allow your amplifier to draw the juice it needs from the battery more easily.

If you don't have the manual, or plan a multi-amp system, you should check out our Cable Gauge Chart to determine the proper gauge of wiring to use. You will be asked to supply the total RMS wattage of your system, as well as the estimated length of your intended power cable. By figuring in a typical amp's efficiency and the normal voltage of a running car, you'll find out the maximum current the amp will draw from the electrical system and exactly which size wire you'll need so it will all work properly.

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Q: What's this thin blue wire for?

A: The thin blue wire is called the turn-on lead, as it carries a signal that turns on your amplifier. The turn-on lead runs between the amp and your receiver. You wouldn't want your amp to be on all the time, draining your battery dead every time you park. The turn-on signal triggers an electronic switch inside the amp that powers it on whenever the receiver turns on. The turn-on lead must be connected properly in order for your amp to power up.

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Q: How much air space do I need around my amplifier?

A: An amplifier produces heat, which its heat sink absorbs and dissipates. You should leave a few inches of air space around each side of the amp so that it stays as cool as possible. When mounting an amp on a side wall (vertically), make sure that the fins on the heat sink are also running vertically so the heat escapes more easily. Don't mount an amp upside down — the amp will not be able to dissipate heat effectively, and overheating can damage or destroy your amp.

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Q: How do I hook up multiple amplifiers?

A: You must supply power from your battery to every amplifier in your system. You could run a separate power wire to each amplifier, but a power distribution block will give you a cleaner installation with less potential for noise problems.

Let's say that you want to install a 200-watt mono subwoofer amp, a 75W x 4 amp for your door and rear deck speakers, and a 30W x 2 amp for your dash speakers — 560 watts of total system power. Run a single 4-gauge power wire from your battery to a 3-way (or 4-way) distribution block next to your amps. From the block, 8-gauge cables supply power to your subwoofer and multi-channel amplifiers, while a 10-gauge wire feeds the 30 x 2.

Ground your amplifiers in reverse fashion — one 10-gauge and two 8-gauge ground cables run from the three amplifiers to a 3-way grounding block. Then, a 4-gauge ground cable connects the grounding block to your vehicle's chassis.

In multi-amp systems, the remote turn-on output of the receiver could become overwhelmed and fail. In that situation, you'll need a relay on the turn-on lead that gets triggered by the receiver but gets the 12-voly turn-on signal from somewhere else, like the fuse box.

Normally you use RCA patch cables to send the signal from your receiver to your amplifiers. A receiver with 3 sets of preamp outputs can provide signal for your front, rear, and subwoofer amps. If your receiver has only one set of preamp outputs, you'll have to use Y-adapters to provide signal to a multi-amp set, or use amps with built-in preamp outputs that allow you to daisy chain the signal from one amp to the next.

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Alpine X-A70F

Alpine X-A70F 4-channel amplifier — 120 watts RMS x 4

Q: My amplifier is hooked up, but it won't turn on. What's wrong?

Check (and repair if necessary) the following:

  • Do all the other electrical systems in the car work?
  • Is the receiver turned on?
  • Are the on-board fuses in the amp good?
  • Is the in-line fuse on the power cable near the battery good?
  • Is the power cable from the car battery to the amp firmly connected at both ends?
  • Is the ground cable from your amp firmly connected to the car's metal chassis with no paint or varnish interfering with a clean electrical contact?
  • Is the turn-on lead (usually blue) to the amp from the receiver properly connected? (Set the receiver to the tuner or radio mode. If your amp now comes on, it means the turn-on lead was wired to the receiver's power antenna lead by mistake and needs to be correctly re-wired to the remote turn-on lead connection.)
  • If this is a multi-amp system, have you tried powering up just one amp at a time? (The turn-on signal has a limited capacity. In multi-amp systems it is often necessary to use the turn-on signal from the receiver to power a relay, which in turn supplies the turn-on signal to the amps from another power source.)

If the answer to all those questions was yes and your amp still doesn't come on, then perform the following test:

  • Remove the in-line fuse on the power cable.
  • Disconnect the turn-on lead from the amp and tape the end so it can't contact any metal.
  • Take a short length of wire and connect it between the amp's remote turn-on terminal and its positive power terminal, leaving the power cable connected to the amp.
  • Replace the power fuse.
  • If the amp now comes on, the turn-on lead wire, or the signal itself, from the receiver is bad and should be repaired. Replacing the turn-on lead usually fixes this. Otherwise you'll need to provide that signal (+12 volts DC) from somewhere else, like the car's fuse box which only gets powered when the ignition's on. You do not want to leave the turn-on lead jumped to the amp's positive terminal because that way the amp will never shut off, draining your car's battery dead.
  • If the amp did not turn on, you most likely have a damaged amp and need to replace it or contact your dealer to arrange for its repair.
  • One last check, if you have and know how to use a voltmeter, while that remote jumper wire is still attached, measure the voltage at the amplifier's power terminal and remote turn-on terminal. If it reads about +12 volts DC or more each, then your wiring is good but your amp is bad. If you don't get the right voltage at the amp, then you know to keep looking for a wiring problem.

Important Note: For your personal safety, and that of your equipment, always remember to remove the power fuse before disconnecting or reconnecting your amplifier.

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Q: How much power do I need to get optimum performance from my car's sound system?

A: Since every car stereo is different, there's no magic "wattage formula." As long as you stay within the recommended power range of your speakers, increasing power will always add richness and depth to your music. Compare a spinet piano to a concert grand. The small piano is good enough to play music clearly, but move up to a grand and you'll gain better tone, greater harmonic detail, and more volume. The larger instrument is simply more powerful.

Here are a few things to consider, though:

  • How efficient are your speakers? Your speakers themselves have a direct influence on the overall "power" of your system. If you plan to power your speakers with your in-dash receiver, efficient speakers (sensitivity of 90 dB or higher) will give you more bang for the buck. Installing high-performance component speakers? An outboard amp will generate maximum performance.
  • Are you adding a subwoofer? Subs need substantial amounts of power to reproduce bass, so it's absolutely essential to use an outboard amplifier with them. You should count on using more power for bass than you use to power all your full-range speakers. Most factory receivers can put out about 10 watts per channel, so a sub amp of from 50 to 100 watts RMS will keep up nicely. If your aftermarket receiver puts out 20 watts RMS x 4 channels (80 watts total), send at least 200 watts to your sub. Using a 50 watt x 4 amp to drive your components? Dedicate about 250 to 500 watts for bass.
  • How good is your wiring? Your system's chain of components is only as strong as its weakest link, so don't cheat your amps and speakers with substandard power cable and speaker wire.
  • Before you buy, consider your car. If you drive a quiet car with the windows up, you'll need much less power than someone who offroads in a Wrangler. Speaker location, extraneous road/car noise, noise damping material, and personal taste are factors that may affect how much power you'll need in your system.

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Q: What's the biggest amp I can hook up to my car's electrical system?

A: Your car's alternator ampere rating determines how powerful an amplifier you can install. Multiply the ampere rating by 40%, and you'll get a rough idea of how much reserve current capacity your car's system has. Next, you'll need to calculate the approximate current draw of the amplifier you're considering installing.

To calculate the current draw of an amplifier, multiply the number of channels by the RMS watts per channel (a 2 channel amp rated at 300 watts RMS per channel would be 600 watts). Double it to account for amplifier inefficiency (600 watts X 2 = 1200 watts), then divide by the average output Voltage of an alternator, 13.8 volts (1200 divided by 13.8 = 87 amps). Since the average music signal requires about 1/3rd of the average power in a test tone, divide by 3 (87 amps divided by 3 = 29 amps). The result is the amplifier's approximate average current draw while playing music at top volume.

A fast-and-nasty way to ballpark an amplifier's current draw is to divide the total fuse value of the amp by two. For amplifiers with multiple fuses, the rating of all fuses provided with the amp must be added together. This will likely produce a significantly higher estimate than using the proper formula. Although inaccurate, this will err on the side of safety.

Finally, compare the amplifier's approximate current draw to your vehicle's reserve current capacity to determine if the electrical system can support the amplifier.

If all those numbers are a bit much, here's a simpler way to think about it: an alternator capable of producing 65 amperes is usually adequate for systems up to 540 watts RMS. A compact car with a 35-amp alternator can accommodate around 290 watts of power, while a Sport Utility with a 145-amp alternator should handle a 1200 watt system. A capacitor can help if your system is drawing a little too much power. Car audio competitors often replace their vehicle's alternators with heavy-duty upgrades to accommodate big power demands.

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Q: Where should I ground my amp?

A: Your ground wire should be of the same gauge as your power wire and must make direct contact with the metallic body of the car. Look for an existing bolt or screw that makes contact with the car chassis or frame near the amp. Remove the bolt or screw, and scrape away any paint or grime.

A star washer will help your ground wire maintain solid contact with the car body. Use a ring terminal on the end of the ground wire, to keep it securely fastened to the bolt or screw. If you can't find a convenient ground screw or bolt, drill a hole for one. Be careful not to drill into the gas tank, a gas line, or a brake line. If you're grounding multiple components, try to ground them all to a single bolt,

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Q: What is a "high-current" amplifier?

A: An amplifier is considered a "high-current" amp if it can handle low impedance loads — less than 2 ohms per channel, less than 4 ohms when bridged — without overheating or shutting down. In a perfect world with a perfect amplifier, power output would double every time the impedance was halved. For example, an amplifier rated at 50 watts RMS x 2 channels into 4 ohms would produce 100 watts by 2 into 2 ohms. Unfortunately, this is not a perfect world, and most amplifiers can't do that.

The best way to identify a high-current amplifier is to look at what happens to the power rating as the impedance drops. The closer it comes to achieving the perfect world scenario above, the more current it is capable of passing.

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Kicker 44KXA800.1

Kicker KXA800.1 mono subwoofer amp — 800 watts RMS x 1 at 2 ohms

Q: How much power do I need for my subwoofers?

A: That depends on what sort of bass impact you hope to achieve. If you just want to hear a bit more bass than your regular stereo speakers can put out, you can get what you need with an efficient 6-1/2" subwoofer driven by as little as 50 watts RMS. But when you're looking for really big bass, you'll need at least a 10" or 12" subwoofer and a minimum of 150 to 200 watts to drive it. Low bass notes are power hungry, and the more wattage you feed them, the better they sound. In general, the larger your subwoofer and the harder you want it to hit, the more power you'll need.

Here's a good rule-of-thumb guide to sub power:

  • If you're using your car's factory stereo — 50 to 200 watts RMS of power for the bass will do nicely.
  • An aftermarket receiver — you might want 200 to 300 watts RMS of power for your sub.
  • Amplified speakers with around 50 watts RMS per channel — plan on 250 to 500 watts RMS for bass
  • A 100 watts RMS or higher per channel system — you'll want at least 1,000 watts RMS for your sub.

We usually recommend that you drive your speakers/subwoofers with at least 75% of their total maximum RMS (not peak) rating to get them to perform at their optimum. The closer to 100% you power them, the harder they hit and the better they sound.

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Q: What should I know about my speakers' impedance?

A: Impedance is the electrical resistance of a speaker or sub's voice coil to the voltage put out by an amplifier. Unlike the fixed resistance value of a resistor, a coil's impedance varies with the frequency of the signal. The "nominal" impedance rating of a particular speaker or sub is the value the manufacturer has asigned to it for the useful calculation and application of power. That impedance represents the load the amplifier has to work against to produce sound. The lower the load on the amp, the more power it can put out.

Unfortunately, there are limits to how low a speaker's impedance can be before the amplifier tries to put out more power than it can, over-stresses, and probably shuts down. The minimun impedance most car amplifiers are stable for (can handle) is a 2-ohm load on each channel or a 4-ohm load on bridged channels.

Almost all full-range car speakers have 4 ohms of impedance. Subwoofers come in a variety of impedances and even the number of voice coils. This is so you can combine multiple subs together, in various configurations, and achieve a total impedance that your amplifier can handle.

When speakers or subwoofer voice coils are wired in series — one after the other, a plus of one to a minus of another — you add their impedances to get the total impedance. Two 4-ohm voice coils in series make an 8-ohm load. When you wire speakers or sub coils in parallel — each terminal connected to the same pole, plus to plus, minus to minus — you take the impedance value of one coil and divide it by the number of coils. Two 4-ohm speakers wired in parallel make a 2-ohm load.

See Wiring Subwoofers — What's all this about Ohms? for more about impedance-matching. You should also keep in mind that when two speakers are wired together, whether in series or parallel, they share the power given them evenly, one-half of the total to each.

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Q: How can I drive a pair of speakers and a subwoofer with a single car audio amplifier?

A: One way is to get a 3-channel amplifier, with two channels for your front speakers and a dedicated single channel with more power for your sub. But this leaves no room for future expansion. A key to getting the most out of your audio investment is choosing gear that will go to work for you now, and won't become obsolete as your system grows. Most car audio amplifiers boast a design flexible enough to keep them in the game as your set-up expands.

If you go with a 4-channel amplifier, powering a pair of front speakers and a subwoofer is a breeze. You'll simply want to run your amp in what we call 3-channel mode. To do this, bridge the rear channels to power your subwoofer, while the front channels drive the pair of regular stereo speakers. Bridging the rear channels means combining them in mono mode to create a single channel. Choose an amp that lets you engage a built-in, low-pass filter on this bridged channel. The crossover, along with the increased output from the mono channel, makes this an ideal way to power your sub.

As your system grows, you may dedicate a separate amplifier to your sub. At that time, you could add another pair of stereo speakers for rear fill, and run your 4-channel amp in 4-channel mode.

There used to be a way to utilize a 2-channel amp to drive two speakers and a sub that was called the "Tri-Way mode." This method used a special "Tri-Way" crossover connected to the two channels of the amp that created a third, subwoofer channel. If your 2-channel amp is Tri-Way capable, a Tri-Way crossover setup may be just the affordable solution for your system's upgrade.

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Q: My new car amplifier is "2-ohm stable." How can I take advantage of that?

A: Amps usually put out more power to a 2-ohm load than to a 4-ohm load (most speakers). Amplifiers advertised as 2-ohm stable can safely drive a 2-ohm speaker or sub on each of its channels. One way to take advantage of this is to wire two 4-ohm speakers together in parallel, making a 2-ohm load, to each channel of your amplifier. You'll get twice the number of speakers and, usually, twice the amount of total power.

"2-ohm stable" does not mean the amp can drive a 2-ohm load with bridged channels — in fact it means it can't. An amplifier would need to be "1-ohm stable" in order to safely drive a 2-ohm load with bridged channels.

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Q: What's the story on the different amplifier "classes"?

A: Amplifiers are divided into different classes defined by how their internal circuitry works.

Class A amps always have current flowing through their output transistors (or tubes). This is an extremely inefficient method of raising power and Class A amps are large, heavy, and run very hot. The upside of Class A operation is its linearity — Class A amps produce the cleanest output with the best fidelity and least distortion of any other class of amplifier.

Class B amps operate with each of their output transistors having current flowing through them only half the time, switching off when the signal's not there. Class B amplifiers are very efficient, but distort the signal due to all the on/off switching at the output.

Class AB is a combination of the two, where the output transistors power-down a little when not in use, resulting in good sound fidelity and adequate efficiency (often 50%). Most home theater and stereo amplifiers use Class AB technology.

Class D amps operate by rapidly switching their transistors on and off, which greatly increases amp efficiency, sometimes reaching as high as 90%. In effect, a Class D amp takes the input signal and maps it onto pulses of high current generated by the power supply. This creates a bit of high frequency distortion, above hearing range, that is easily removed with a low-pass filter at the output. Class D amps can be very small for their power ratings, and that's why they're showing up more and more in the mobile audio world where space is at a premium.

There are a few other amplifier classes — like Class C for radio frequencies and Class E for pulses, not audio — but they're either rarely used in car audio or are actually hybrids of other classes.

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Q: What's the difference between "parallel" and "series" wiring?

A: When you wire a pair of speakers in parallel to an amplifier, you connect the positive (+) leads of both speakers to the amp's positive (+) terminal and the negative (-) leads of both speakers to the amp's negative (-) terminal.

If you parallel wire two 4-ohm speakers, the amp sees a 2-ohm load. This lower ohm load (lower resistance) allows the amp to put out more power but run hotter. Amps that can handle this additional heat build-up are considered 2-ohm stable.

Series wiring works the same way as flashlight batteries; the positive end of one speaker is connected to the negative end of the other speaker. Wire from the positive terminal of the amplifier to the positive terminal of one speaker. Then wire from the negative terminal of the first speaker to the positive terminal of the second speaker. Finally, run a wire from the negative terminal of the second speaker to the negative terminal of the amplifier.

If you series-wire two 4-ohm speakers, the amp will see an 8-ohm load. This higher ohm load (higher resistance) inhibits the flow of current out of the amp. You get less power, but the amp runs cooler and is more stable.

Parallel and Series Wiring

You can run more than one speaker from a single amp channel by wiring the speakers in series or in parallel. Series wiring will raise the load (resistance) that your amp sees, and parallel wiring will lower it. Be certain your amp is 2-ohm stable before wiring speakers in parallel.

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Q: When should I use a mono amplifier instead of a multichannel amplifier?

A: Mono, 1-channel amplifiers are for subwoofers. They're designed to work with a wide range of impedances, and have tone controls and filters specifically made to help reproduce bass. Because mono amps tend to be Class D amplifiers, they are a good choice for powering subwoofers — Class D amplifiers have a high power-to-heat ratio and excellent efficiency, which are exactly what you want when dealing with power-hungry low frequency signals.

Most mono amplifiers are designed to run at 2 ohms, though some are even 1-ohm stable. Multichannel amplifiers, on the other hand, are typically designed to work with 2-ohm loads on individual channels but must see a minimum of 4 ohms when bridged. This is an important difference when using your amp to power multiple subwoofers, because you won't be able to bridge your multichannel, 4-ohm stable amp to power multiple subs that present less than a 4-ohm load. Instead, use a mono amplifier to power a 2-ohm load — two 4-ohm subwoofers, or two 2-ohm dual voice coil subwoofers, for example. You'll be able to push your subwoofers with the mono amp's maximum power, without running at a dangerouly low impedance.

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Q: What are the benefits of hooking up 2 subwoofers to a mono amplifier? How would I wire them?

A: The benefits of hooking up two subs to a mono amplifier are the same as hooking up any other number of subs to a mono amp: you can push the subs with more power at lower impedances. Because lower frequencies are less directional (i.e. it's more difficult for your ears to determine where low frequencies come from than highs), bass is often transmitted in mono. Mono here refers to a single channel (as opposed to stereo, or two channels), not one speaker.

Most mono amps have two sets of speaker terminals for convenience of installation: if you are hooking up two subs to the amp and using large-gauge wire, it gives you a place to attach the wires without having to trim them, appearing as if each subwoofer gets its own terminal. But in reality, these terminals are actually tied together inside the amp — both positives are going to the same place inside the amp, as are both negatives. If you are using more than two subs, then you simply use parallel or series wiring (or a combination) to get as close to the minimum impedance of the amp as possible (see our subwoofer wiring diagrams for more information).

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Q: What is "bridging" an amplifier?

A: : Bridging combines two of an amplifier's channels into one channel, in order to get more power. For example, a 2-channel amp that puts out 75 watts RMS per channel at 4 ohms may be able to put out as much as 200 watts RMS at 4 ohms into one channel when bridged, which could be great for running a subwoofer. There are no formulas for determining how much power you gain when you bridge an amp's channels — every amp is different. Most 2- and 4-channel amplifiers have the capability of being bridged so they can conveniently be used in a variety of situations and systems. Another example might be using a 4-channel amp to drive your left and right speakers with two of its channels, while driving a sub with its other two channels bridged together, saving you the need to buy a separate sub amp.

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Q: Are there any problems in bridging an amp?

A: A disadvantage in bridging amplifiers is that you must be careful not to hook up too low of an impedance load, or you could damage the amp. Amps that work with loads as low as 2 ohms per channel usually can safely drive loads only as low as 4 ohms when bridged. The danger in driving an amplifier with an impedance load that's too low is that the amp could overheat and burn out. You should always check the bridged minimum impedance specification before connecting a bridged amplifier to a low impedance sub or speaker system.

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Q: Can I bridge my mono amplifier?

A: No, you cannot bridge a mono amp because there is nothing to "bridge." Bridging means combining two amp channels together into one, in order to get more power. If you only have one channel, there's nothing to combine it with.

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Q: I'd like to add an amplifier to my factory car radio. What are my options?

A: Because it's a great way to increase musical detail, dynamic range, and volume, adding an amplifier is an extremely popular factory system upgrade. And when the weather gets warm, even more people tell us they're looking for a system that can deliver roll-down-the-windows volume.

In addition to running power, ground, and a remote turn-on lead, your amp hook-up requires input signals. Your factory radio won't have RCA outputs to connect to your amp's inputs, so you'll get the signals from your vehicle's factory speaker wires. You'll want to get an amplifier that has high- or speaker-level input capability. But if you already have an amp and it doesn't accept such a high level of input, you can use a line output converter to lower it to RCA-level.

If you're just adding a subwoofer and subwoofer amp to a factory system, you tap into the factory speaker wiring, either behind the radio or from the rear speakers, and use that speaker-level signal for your amp's input. Mono subwoofer amplifiers take two inputs, left and right, and combine them internally to form the monaural signal used for subwoofers. For these and most other kinds of connections check out Posi-Products wire connectors — they make quick, easy, and reliable electrical connections with no crimping, soldering, or messy tape.

To amplify your front and rear speakers with a 4-channel amplifier you cut the factory speaker wires and connect the ends coming from the radio to your amp's inputs and connect the ends going to the speakers to your amp's outputs. A convenient place to make these connections is behind the radio where all the vehicle's speaker wires are accessible in one location. If you plan on a high-powered system using, say, a 100 watts per channel amp, however, then you'll want to run new and thicker speaker wires directly to each speaker from your amp's output.

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Q: How do I fine-tune my amplifier's gain and bass boost settings?

A: One of the final steps in any amplifier installation is to set its gain properly. Setting the gain matches your amplifier’s input level with your receiver’s output level, resulting in maximum distortion-free music and minimum background noise.

  1. Start with all the receiver's EQ presets and tone controls off or set to flat. On your amp, disengage all filters, set the bass boost to zero, and turn the gain down low.
  2. Play some familiar music and turn up the receiver's volume until you hear the music start to distort, then turn it down a little so it plays clean. If you don't hear any distortion, even at full volume, set the receiver's volume to ¾ full.
  3. Slowly turn up your amp's gain until you hear the music start to distort, then turn it down a little so it plays clean again.
  4. Lower the receiver's volume to a comfortable listening level. Keep playing the familiar song over and over again, as you continue tuning your system.
  5. On the receiver, adjust the EQ presets or tone controls to how you like your music to sound.
  6. For a 2- or 4-channel full-range amplifier, engage the amp's high-pass filter and adjust it to remove the lowest bass notes from the full-range speakers. Those low notes would probably be the first ones to distort through those speakers when you turn up the volume later. For sub amps, turn on the low-pass filter and remove anything that's not bass from the subwoofer's sound.
  7. The bass boost is another kind of EQ or tone control dedicated usually to one particularly low note. Experiment carefully by applying it and listen to how it affects the tone of the bass and set it to where you like it.
  8. Re-set the amp gain — turn the amp's gain down first, and then repeat steps 2 and 3. Turn up the receiver's volume until you hear the music start to distort, then turn it down a little so it plays clean. If you don't hear any distortion, even at full volume, set the receiver's volume to ¾ full.
  9. Slowly turn up your amp's gain until you hear the music start to distort, then turn it down a little so it plays clean again.
Re-setting the gain (those last two steps) is important, to compensate for whatever EQ or boosts were applied, so your amp's gain will be set for exactly how you listen to your music.

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Q: What is the difference between Peak Watts and RMS Watts?

A: RMS wattage is a measurement of power capacity used for comparing and matching components together. Peak wattage, often double the RMS value, is a description used by the marketing department of the amp's manufacturer to sell more amps. You should only use RMS ratings when comparing and matching gear.

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JL Audio XD800/8v2

JL Audio XD800/8v2 8-channel amp — 75 watts RMS x 8

  • ChrisK Rose from pontotoc

    Posted on 11/20/2020

    I have a Pyle plmra420 1000watt 4 channel amp in using with a single 500watt audiopipe sub. my head unit is a Pioneer DEH-S31BT. in addition I have 4 new schoshe 300watt 4way 6x9's. I would love direction on how to use my amp's other 2 channels to power the rear speakers. my sub is bridged on 1 and 2...but I'm not utilising the other 2 channels. Pioneer has been ZERO HELP AND SO HAS PYLE! AFTER SEVERAL E-MAILS AND ATTEMPTS TO SPEAK TO A TECHNICIAN(WHO HAS ACTUALLY INSTALLED A CAR STERO) AT BOTH COMPANIES, I HAVE GIVEN UP ON BOTH..FOREVER ! ANY HELP FROM CRUTCHFIELD AT ALL WOULD BE GREAT.

    Buck Pomerantz from Crutchfield

    on 12/6/2020

    Chris, The system update you describe would require a 2-channel RCA cable run from the receiver's rear RCA outputs through your vehicle, to the amp's channels 3 and 4 inputs. Disconnect the rear speakers' factory wires and then run new speaker wire from the amp's 3-4 outputs to your speakers. In this case, 16-gauge speaker wire will work fine.
  • Daniel Hadley from Beaumont

    Posted on 9/21/2020

    I have 2 RW10D4 and need to know what amp I need to buy to get the best and hardest hit I can get from them comfortably

    Buck Pomerantz from Crutchfield

    on 9/23/2020

    Daniel, If you're referring to Alpine Type R W10 D4 subs, then two of the DVC 4-ohm subs rated for 750 watts RMS each will sound good powered by an amp that can put out up to 1500 watts at 1-ohm, like a Rockford Fosgate R2-1200X1.
  • reggie jordan from hill city,ks

    Posted on 9/15/2020

    hello, i had 1100 watt speaker ,what size amp should i use

    Buck Pomerantz from Crutchfield

    on 9/15/2020

    Reggie, Without knowing precisely what speaker you're referring to, we can't help you with advice. If you want a question answered about a system, you must identify the gear by brand names and model numbers so we can get the right information to you.
  • Landon Hammett from Birmingham

    Posted on 8/8/2020

    So I currently am running a BOSS 4000D amp. It's monoblock and it reads it should be putting out 750 RMS @ 4 ohms. My subs have been blown twice. Same subs just got another pair. They were kenwood 12" subs that I thought fit the parameters of the amp but I think I was just purchasing poorly made subs. Any suggestions on what subs to run now? Tired of blowing subs when they're not even put to their max power. I ususally kept them around 60-75% power.

  • Jim from Minneaopolis

    Posted on 8/3/2020

    I am surprised that you would say to drive your sub woofers 75% of maximum RMS for best sound I would think they would sound better at a lower say 30%- 40% I would think the larger the sub woofer and the smaller amount it moves would create the best low distortion sound? The more they move the more port and cone (physical noise) ect would be present?

    Buck Pomerantz from Crutchfield

    on 8/4/2020

    Jim, Speakers and subs sound their best when you power them with at least 75% of their top RMS rating. Less, and background noise becomes audible. More, and you risk blowing the speaker or sub.
  • Adam Booker from Richmond

    Posted on 7/15/2020

    Thank you, great article to refresh my old brain. I just ordered a new JVC head unit and 4 new Rockford Fosgate 167.2 door speakers for my 2005 Toyota Sequoia from you guys. Already have an older 300 watt 4 channel Pioneer amp and a nice 8"JL Audio Sub and would like to build a powered system with the front channels of the amp powering all 4 of my door speakers and the rear amp channel bridged to run the JL Audio 8" sub box. I think i can try the "parallel" method for the door speaker and run bridged on the rear. Thanks !

  • Frank from Upland, Ca

    Posted on 7/7/2020

    I just purchased an Alpine PWD-X5 from you guys for my 2019 Sprinter Van with an OEM 7" screen audio system. There are only two speaker outputs to tap into and I would like to use 2 front and 2 rear speakers. Will the Alpine software allow for this, or do I have to duplicate the inputs etc...?

    Buck Pomerantz from Crutchfield

    on 7/8/2020

    Frank, That sub/amp has four speaker outputs. Call Crutchfield Tech Support for help getting your system together.
  • Clint Mckaskle from Manila

    Posted on 6/15/2020

    Hello i have a 2001 GMC single cab and im looking to add amp(s) to it to increase sound quality. In the doors i have a set of kenwood kfc650 speakers at 320W peak power and 75w RMS. And i have kenwood excelon kfc-x463c rear pannel speakers and 4ohm 2000w kenwood 12inch subwoofers coming in. What kind of amps and wiring kit should i get to complete my install?

    Buck Pomerantz from Crutchfield

    on 6/16/2020

    Cliff, A good solution for you would be a 5-channel amplifier. I don't know what's available in your country, though. An online search ought to come up with something in your town.
  • jelle

    Posted on 6/12/2020

    when calculating the maximum amp for your cars electrical system, does it matter if the speaker/sub runs on 2 ohm or 4 ohm? does the amp draw more power from the electrical system when running on 4x200 at 2 ohm than 4x130 at 4 ohm?

    Buck Pomerantz from Crutchfield

    on 6/12/2020

    Jelle, To play it safe, use the higher 2-ohm ratings. In practical use, use the wattage that the amp will actually put out, whether connected to 2-ohm or 4-ohm loads.
  • Michael H from Nederland

    Posted on 6/11/2020

    I am running qty 2 Rockford Fosgate P3D2 10's with a Rockford P1000X1BD amplifier. I have a 4guage wiring kit and blew the 80 amp fuse in the first 2 minutes. Then put in the 100 amp fuse and blew it after 1 day. Do I need a larger fuse? Possibly larger power wire? OR is there a larger issue at play here? Thanks

    Buck Pomerantz from Crutchfield

    on 6/12/2020

    Michael, That amplifier's specs call for 4-gauge power and ground wires plus a 140-amp fuse.
  • Paul from Powhatan

    Posted on 6/5/2020

    If a 4 channel amp is rated 65 watts RMS per channel, is that too much power for speakers rated 40 RMS? What about 55 RMS? I've read a lot about underpowering speakers, but I don't want to overpower them either. Thanks for any guidance!

    Buck Pomerantz from Crutchfield

    on 6/8/2020

    Paul, There's a lot of misinformation about "under-powering" speakers and subs. Turning down the volume doesn't damage a speaker, so using a small amp won't either. Only over-powering damages speakers. For speakers rated for 40 watts RMS, we recommend using an amplifier with no more than 40 watts RMS per channel.
  • Karl deGaris from Fernandina Beach

    Posted on 6/1/2020

    I have older Kenwood amps, the 901, 801 and an 8020. All still work, as verified with an equally as old Kenwood tuner unit. My question is; They all have the old style DIN plug low level inputs that were Kenwood specific. Is there an adapter available so these amps could be used with the standard RCA plugs as found on new AM/FM - CD/DVD units? Thanks for your help.

    Buck Pomerantz from Crutchfield

    on 6/3/2020

    Karl, You'll have to ask Kenwood tech support for information about DIN to RCA adapters.
  • George Heard from Wisconsin

    Posted on 5/22/2020

    Good Evening Butch. I have a few questions. 1st question, with Pioneer head units having built in equalizers, would you recommend running an old pioneer eq-6500. 2nd question, do you think a Rockford Fosgate bd 2001 2004-2006 would have enough power 2 push 2 15s Cerwin Vega spcl152's. Last question. I have a Audio Control 4xs crossover. Is it needed or will it hurt my system ?

    Buck Pomerantz from Crutchfield

    on 5/25/2020

    George, Wired like this, that amp will power those subs just fine. You haven't given any reason for using an outboard equalizer or crossover, so I can't recommend them.
  • William B from Middletown

    Posted on 5/14/2020

    What is the recommended voltage output for a Kenwood 401/4 XR For setting gains?

    Buck Pomerantz from Crutchfield

    on 5/14/2020

    William, I personally don't recommend using output voltage readings to set gain because you never know whether the signal's clipping or not. But mathematically, to achieve 75 watts RMS, the optimum output of the amp, through a 4-ohm speaker will take 17.3 Volts AC.
  • mike from Atlanta

    Posted on 4/28/2020

    I have a 600 RMS amp - 4 channels. Bridging 4ohm Subwoofer - sub to be wired parallel. I also have 4 - 60 watt / 4 ohm speakers to be wired in series to the remaining 2 channels - will this work? Should sub be wired parallel / speaker wired in series? Worried about blowing the 4 - 60 watt speakers (4 ohms as well).

    Buck Pomerantz from Crutchfield

    on 4/30/2020

    Mike, Not knowing exactly what amplifier or subwoofers you have make it impossible to give advice on how to wire them together. If you want a question answered about your system, you must identify your equipment by brand names and model numbers. I can show you two speakers wired in parallel, and two speakers wired in series, if that helps.
  • o young

    Posted on 4/25/2020


  • PeterGomes from bogura

    Posted on 4/1/2020

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  • Haans

    Posted on 11/22/2019

    I have questions regarding my Sony amp's ohm and front speakers ohm. I have a pair of front JBL GTO638 6.5-Inch Speakers rated 2ohm. Another pair of rear speakers rated 4ohm. I have my workshop configured Clarion XC1410 powering the rear speakers. This is fine. My concerns is on the front speakers powered by Sony XM-N1004 amp. The amp is capable to support 2ohm. But based on speaker ohm calculations, the front pair speakers are 2ohm each. Effective ohm is =1ohm. I am worrying that my Sony amp will heat up and fried. Am I right with my concern?

    Buck Pomerantz from Crutchfield

    on 11/22/2019

    Haans, I don't know why you'd use two 4-channel amps to drive four speakers. The Clarian amp is non-bridgeable and the Sony amp can't handle a 2-ohm load when bridged. Either one of the amps alone can power your entire system.
  • jayson

    Posted on 7/23/2019

    your item is available?

  • TC Smythe from Westcliffe

    Posted on 6/26/2019

    My question isn't about a car sound system, but I'll bet you know the answer anyway. As a live musician ( not a dead one!) I use 4 powered speakers each with a 1000 watt RMS rating. I have never even come close to using even 10% of what they *can* do, but wondered how much current they need to draw during that one second right after I turn them on. The owners manual and specs don't talk about their initial power requirement - only their upper limits under an active load. Any thoughts?

    Buck Pomerantz from Crutchfield

    on 6/27/2019

    TC, The spec you're looking for is called "current draw while idling" - but nobody publishes that.
  • Rafael Baez from ANAHEIM

    Posted on 6/1/2019

    Do i have to buy 2 car amplifier kits for two amps ?

    Buck Pomerantz from Crutchfield

    on 6/3/2019

    Rafael, You can use a dual-amp wiring kit, like Crutchfield's CKD4.
  • Tristen from Eugene

    Posted on 5/25/2019

    Hello, I have a alpine Mrv M500 amp under the seat of my 2016 Camry. It powers a single Diamond audio Sub with 4ohm dual voice coils. The sub is wired to a 2 ohm load. The subwoofer works fine my issue is when I turn off my car the subwoofer fires one low note for about a second. This has happened since I installed the system 6 months ago. I am used to it by now but it scares my passengers. This happens even if I do not play any music and turn my car off. Any ideas?

    Buck Pomerantz from Crutchfield

    on 5/28/2019

    Tristen, Your remote turn-on lead may be wired to a constant voltage instead of a switched source. But something is also sending that one note to the amp, however it's wiring into the system. If you bought your amp at Crutchfield, you could call Tech Support for free help troubleshooting your system. Their toll-free number is on your invoice. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Click on this link for details.
  • Levi from Bozeman mt

    Posted on 4/25/2019

    I have a 600w rms (duel) amp and a 150 rms 10" (kicker) woofer. My question is will my amp overload my woofer and vise versa?

    Buck Pomerantz from Crutchfield

    on 4/25/2019

    Levi, An amplifier that puts out four times the power rating of a sub will probably blow the sub to pieces.
  • Thomas from Ft. Irwin

    Posted on 4/4/2019

    Hello I recently bought a JL Audio XD400/4v2 and a JL audio XD600/1v2 along with a crutchfield brand multi amp 4ga wiring kit. My question is would the wiring kit be ok with these amps and running from the battery under the hood of a 2015 accord to the trunk to a fused distro block then down to two 8ga runs to the amps? The small runs would be about 2ft and the main 4 ga run would be close to 16 ft.

    Buck Pomerantz from Crutchfield

    on 4/5/2019

    Thomas, A 4-gauge main power cable will work fine for your amps. Class D amps are more efficient than a typical AB amp and will draw less current from the power supply and can use smaller power wires. (See answer on the Wire Gauge Chart comment section for more detail.)
  • Khaja naseeruddin from Gulbarga India

    Posted on 2/20/2019

    I have a pioneer component speaker with 60 watts RMS in front door, Sony coaxial 40 watts RMS in back door and pioneer 3 way 90 watts RMSin the trunk. I am planning to purchase pioneer D 8604 amp and a self powered subwoofer. How do I connect the 4 channels of the subwoofer

    Buck Pomerantz from Crutchfield

    on 2/21/2019

    Khaja, You might want to look through Crutchfield's Car amplifier installation guide for help with your install.
  • Chris from Durham,nc

    Posted on 1/27/2019

    If my 5/7 door speaker are 40rms each an my 4 channel amp is 100 rms will they blow. Is it anything I can do

    Buck Pomerantz from Crutchfield

    on 1/29/2019

    Chris, Sending 100 watts RMS through speakers rated for 40 watts RMS can indeed blow them. You can still use that amp to power those speakers if you set the amp's gain low enough so no distortion ever plays.
  • Frankline Joseph from Nairobi

    Posted on 1/19/2019

    I have pioneer GM D8601 with two fuse 40 amps,jec CA 3246 with one fuse 40 amps and 5 Way digital cross over from audio bank. Also have a boschmann graphical equalizer. Have been using two computer psu of each 400watts maximum output. All connected in parallel. They each have 16amps on +12v.. Can I add another computer psu with maximum 430watts (+12 has 16amps) in parallel still? Or it will burn the jec amp.

    Buck Pomerantz from Crutchfield

    on 1/21/2019

    Frankline, I'm sure you can add another power supply to your system. Whether that's safe or not, I don't know. It sounds like you're using these car amplifiers are in a home stereo system. What might burn out is your house's wiring, as the system tries to draw around 90 amperes through thin service wiring.
  • Lewis Kimball from Wickliffe

    Posted on 12/1/2018

    Have a question for you techies. I am in the process of upgrading my factory system in my 2019 Hyundai Santa Fe with the Infinity premium system, to an all Rockford Fosgate (Prime line) system. I have a R600-4D for the mids n highs, RF 6.5 components in doors, the tweeters in dash, and RF 3 way 6.5s in rear doors. My question is: how do I power the ctr channel speaker in the dash, while keeping the balance and fader functionsl on the factory head unit? Also, have there have been any updates on availability of the factory amp output harness to feed an Audio Control LCQ1 so I don't have to butcher or tap into the current factory harness? Any info would be greatly appreciated!!

    Buck Pomerantz from Crutchfield

    on 12/3/2018

    Lewis, The Infinity premium system includes a factory amp that outputs crossed-over signals for tweeters, woofers, a subwoofer, and full-range speakers. You'll probably need to interface the factory amp to your aftermarket amp with a device that can sum the different signals and combine them into a full-range signal for your amp to handle. JL Audio's FiX 86 may be what you need. You can leave the center channel and sub hooked up to the factory amp.
  • Clinton from Cape Town

    Posted on 11/14/2018

    I'm in the process of tuning my Monoblock and 4-channel amp. However my monoblock does not support the LPF frequency that matches the maximum frequency of my subwoofer. Monoblock LPF tops at 250hz, however my subwoofers frequency range is 23-400hz. What do I do in this scenario? On the other side, my split system is rated at 60 - 23k hz, at which frequency should I set the HPF of the amplifier? Would it be at the same point the LPF is set on the monoblock? Eg. 250hz LPF, 250hz HPF?

    Buck Pomerantz from Crutchfield

    on 11/14/2018

    Clinton, Even though your subwoofer is capable of playing notes as high as 400 Hz, you really don't want it to do that. You want your sub to play bass only, with the other amp and speakers taking care of the rest. A good place to start is to set both the LPF of the sub amp and the HPF of the 4-channel amp to around 100 HZ and then tweak to taste.
  • Teddy from Winchester

    Posted on 11/2/2018

    Hi, I recently purchased and installed a KTP-445u power pack in my 2000 Ford Contour. I believe I have everything connected and set correctly however, when the volume reaches medium volume level, all audio cuts out for a second. It's like it cant handle the higher notes. With it being 45W RMS per channel, does this sound like typical operation for this style amplifier? It just confuses me because, my father's factory system in his '01 tundra sounds louder.

    Buck Pomerantz from Crutchfield

    on 11/5/2018

    Teddy, Audio that cuts out for a second doesn't sound good. Maybe the amp's gain switch is set incorrectly. Or there may be a problem with the receiver. If you bought your amp from Crutchfield, you could call Tech Support for free help troubleshooting your system. Their toll-free number is on your invoice. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Click on this link for details.
  • Gustavo Rodriguez from Fort Myers

    Posted on 10/23/2018

    Hi, I recently purchased an alpine MRV-M500 and an alpine MRV-F300. Is the Rockford Fosgate 4awg dual amp wiring kit acceptable for these two amps? I appreciate the help!

    Buck Pomerantz from Crutchfield

    on 10/24/2018

    Gustavo, Yes, that wiring kit will work for those two amps together.
  • Manuel Santana from Springfield

    Posted on 8/29/2018

    Hello, i just bought 2 Soundstream R3s! There 2ohm DVC. My amp is a 4000w 1ohm stable mono block amp. The place i bought them from said to becareful wiring cause depending on the amp i have wiring 2 DVC 2ohm subs would make a independence of .5 an some amps cant take that or it could run to hot. I want plenty of power but dont wanna fry anything. Whats the proper way to wire this set up? Also what does 1 ohm stable mean? Will it not push anything below 1ohm for power or does it just mean it can take 1ohm. Would wiring 2 DVC 2ohm subs in parrallel be fine or no?

    Buck Pomerantz from Crutchfield

    on 8/29/2018

    Manuel, When an amplifier is listed as being one-ohm stable, it means that it can handle a load, the sub's impedance, as low as one ohm. Soundstream R3 subs come in different sizes with different power ratings. I don't know if the amp spec you quote is a peak or RMS rating, nor at what impedance the rating applies to. Without knowing exactly what amplifier or subwoofers you have, I can't give you advice on how to wire them together. If you want a question answered about your system, you must identify the equipment by brand names and model numbers.
  • Austin from st johns

    Posted on 6/12/2018

    I just bought 2 Fosgate p2s (same box) and it came with a CER2600D boss amp. I looked on the website and it says this (488 W X 1 RMS @ 4 ohm). Does that mean it'll run 488W rms each sub or 244W rms each sub? Also the max RMS for the subs is 400 so would running them at 488W rms hurt them?

    Buck Pomerantz from Crutchfield

    on 6/12/2018

    Austin, As long as the subs are wired correctly to the amp, each sub will receive exactly one-half of what the amp puts out. If the subs are wired as a 4-ohm load and the amp puts out 488 watts RMS at 4 ohms, then each sub will receive 244 watts RMS.
  • Buck Pomerantz from Crutchfield

    Posted on 4/16/2018

    Thomas, It sounds like your vehicle keeps the radio on for 1-3 minutes after it's turned off, and keeps the amp on as well. The only solution I see is for you to turn off the factory radio when you turn off the vehicle - the amp should turn off then.

  • Thomas from Norway

    Posted on 4/14/2018

    I have a Pioneer GM-D8604. This turns on automaticly when it feels voltage at the RCA inputs.. So it turns on with my headunit and off when car turned off, but amp doesnt turn off before 1-3 minutes after i have turned of the car. I have allready wired a remote switch to the amp for remote start/stop but it has no effect because of the automatic turn on/off. I dont trust this function. What are my options? Is it possible to get a Low to High 4 channel converter whitch can be toogled on/off?

  • Buck Pomerantz from Crutchfield

    Posted on 3/8/2018

    Mike, The output RMS voltage of an amplifier equals the square-root of the product of the amp's maximum RMS wattage times the subwoofer's impedance. If you want a question answered in more detail about your system, you must identify your gear by brand names and model numbers so we can get the right information to you.

  • Mike from Monroe

    Posted on 3/7/2018

    How many volts or mvolts should i be getting out of my sub amp?

  • Buck Pomerantz from Crutchfield

    Posted on 9/18/2017

    Kevin, Not knowing precisely which receiver you have makes it hard to say what controls you might have to set to get clean bass. If you bought your gear from Crutchfield, you could call Tech Support for free help troubleshooting your system. Their toll-free number is on your invoice. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Click on this link for details.

  • Kevin from Washington

    Posted on 9/15/2017

    For years, I used a USAcoustics USP 200 through a PAC TM 100 tri mode crossover that I used just as a crossover for an 8 in Cerwin Vega sub in a truck box. It sounded fantastic. I recently changed vehicles and bought a Clarion deck with subwoofer outputs. I figured I could use the USP 200 in bridged mode and use the decks crossover instead of the Tri mode. It sounded horrible no matter what I did. I experimented with the amps gain, the decks gain, different crossover points. Nothing worked. I wound using the amps normal outputs and using the Tri mode again. Now I'm hesitant to buy a more powerful amp as I'm not sure I'll like the sound without the Tri mode. What did I do wrong?

  • Buck Pomerantz from Crutchfield

    Posted on 5/17/2017

    Matt, Use the fuse that came with your amp wiring kit. It is there to protect the power wire and your vehicle from catching fire in the event of a short circuit. The fuse's size has been chosen so it will blow before the wire melts or ignites. The amplifier's fuse complement doesn't come into play here.

  • Matt from Missouri

    Posted on 5/17/2017

    Hi. I have an amp that has two fuses - A 35 & 40 amp ATO fuse for a total of 75 amps. If my Amp kit came with a 60 amp AGU Gold plated fuse for the battery, is this fuse big enough or do I need to buy a bigger one? Thanks!

  • Buck Pomerantz from Crutchfield

    Posted on 5/5/2017

    Ashot, For your speakers, almost any car amplifier with less than 250 watts RMS per channel will work. As for your sub, look for an amp that can put out between 300 and 600 watts RMS at 4 ohms. Unfortunately, we're only licensed to sell gear in the United States and Canada and I can't give you a recommendation. I don't know what car stereo equipment or even what model vehicles are available in your country. An online search ought to bring up at least one car stereo dealership somewhere near you.

  • Ashot karapetyan from Yerevan

    Posted on 5/5/2017

    Hi. I have bought PC65.2C and CXX10 and want to buy amp for thees speakers and subwoofer. Can you suggest something, as I can not figure out which one chose. as for price, I would like cheaper)) Thanks a lot

  • Buck Pomerantz from Crutchfield

    Posted on 4/13/2017

    Henry, The remote turn-on lead of the amplifier connects to the remote output wire in the receiver's harness. For that Sony receiver it's the blue with white stripe wire.

  • Henry from Calgary

    Posted on 4/13/2017

    Hi there, I was wondering if you could help me. I spent the better part of a day wiring up my amp to my new radio only to find that it did not turn on. Now, the amp does have a "thin blue wire" or turn on lead that isn't hooked up, but that's only because there isn't a cable for it on the radio? I checked the manual and even tried looking up forums but I found nothing about a turn on lead for the radio. I assumed that perhaps the truck had it's own turn on lead but I could not find that either. The only connection between the radio and the amp is an RCA cable, as I understand it. Is it possible that I am missing something with the radio harness? or is there a wire that sits directly in the dash that I have to connect? Please provide some assistance, it would be greatly appreciated! The radio that I am using is the XAV-AX100 Sony Media Reciever. The amp I'm using is a monoblock 1000w Kenwood amp - KAC-5001PS. It's hooked up to a 350w JL subwoofer. And the truck I drive is a 2006 Ford F150 King Ranch, supercrew. Thank you very much.

  • Buck Pomerantz from Crutchfield

    Posted on 3/6/2017

    Dillon, You need to find out the reason fuses are blowing and correct that issue first. There's a short circuit somewhere in the wiring or the amplifier's faulty. You should never replace an amplifier's fuse with anything except the size fuse the amp came with.

  • Dillon Tyler from Fort Wayne

    Posted on 3/4/2017

    I have a 500 watt amp. I put a 30 amp fuse in it because it kept blowing a 20 and 25 amp fuse but it also blew the 30 amp. What would be best for the inline fuse.

  • Buck Pomerantz from Crutchfield

    Posted on 1/16/2017

    Jamie, JBL and JL Audio both make quality amplifiers, so for bass I doubt you would be able to hear any differences. That JL Audio E-Series amp you mention is a 1-channel amp, so I don't know how it could be used with factory speakers. Why don't you give us a call and one of our Advisors can help you figure out which factory amplifier by-pass harness can be used in your vehicle to install an aftermarket amplifier.

  • Jamie from Lawrenceville, GA

    Posted on 1/14/2017

    I Recently ran across a BARGAIN on a set of JL 10W6v2's that had been stored improperly and the foam surround had all but been eaten away. After making sure they weren't seized and looked to be in pretty good shape other than that, I scooped em up, had them refoamed, and came out with a pair of W6's for around $200 with parts and labor. My question is, I had been running some Fosgate HE2 DVC 10s off a JBL. GTX 500x1 Mono, which I already had a capacitor installed with to try and deal with headlight dimming...etc. So I hooked up my new subs, and they are AWESOME, although I know they must be grossly underpowered. I was thinking of getting another JBL GTX, or possibly keeping with JL, get a new larger JL amp (or 2). Would their be much difference between sticking with JBL, or going with JL amps? Also, my factory mids and highs were barely cutting it before, but with the new subs they're totally overpowered. I have an old JL e1200 amp, would it be possible to replace the factory bose amp with that for more power? Or am I going to be looking at all new mids & highs, because in my last infinti I had the same problem and the factory Amp proved to be a nightmare to deal with. I know an aftermarket head unit would solve a lot of problems, but I really like the factory look and want too keep my navigation...etc if possible. What do you think my best setup options are moving forward?

  • Buck Pomerantz from Crutchfield

    Posted on 1/5/2017

    Walter, I suggest you take your car to an auto parts store or battery specialist and have your battery checked out. The symptoms you describe sound more like you have a weak or worn-out battery rather than a parasitic draw killing it.

  • Walter from Cairo, GA

    Posted on 1/4/2017

    I just installed a pair of Pioneer 12" subs and a mono 2000 watt amp. The subs are 4 ohms in parallel which makes 2 ohms that is within the specs of the amp. My problem......I wired the system, it performed perfectly, the amp is wired using an LOC for the rear speakers and the LOC includes a remote turn on. All works fine.......the amp is off when the car is running and the radio/stereo is off. Turn the radio on and the amp powers up, the power light is on and all is well. Turn the car off or the radio off, the amp shuts off and the power light goes out in a couple of seconds. Sounds like all is fine. No distortion, no frayed ends touching anywhere, 4 gauge wiring to the battery, a suitable 4 gauge ground about 3 feet from the amp. But now, I go out this morning and the battery is dead and car will not even turn over. Charge the battery and the car will start. Nothing else has been changed. All connections are exactly as specified in the wiring diagram for the wiring kit and the LOC instructions. The only thing slightly different is this car has the Microsoft Sync that utilizes the radio system for hands free calling. If I remember it will power up when needed for the conversation and then powers back down. I would think this is a remote function of the head unit itself, but the sync mode was not even used for the last few days and the phone that it syncs with is not even here....belongs to a college age son at school. Any ideas? 2013 Mustang. Thanks.

  • Buck Pomerantz from Crutchfield

    Posted on 10/27/2016

    Joe, It sounds like you have some connections mixed up. If your system was put in by an installer, I suggest you take your car back to them to make it right. If you installed it yourself, you'll need to proceed carefully when implementing a fix - plugging and unplugging cables could produce a spark which could fry delicate electronics. I recommend you first ensure that the speakers are connected to the correct amp channels, and then make sure that the amp channels are connected to the correct receiver channels. If you bought your gear from Crutchfield, you could call Tech Support for free help troubleshooting your system. Their toll-free number is on your invoice. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Click on this link for details.

  • Joe from Petersburg, TN

    Posted on 10/26/2016

    I have a Jensen 4 channel amp (DUBa4100), a Kenwood head unit (KDC HD262u), Rockford -Fosgate 5" (R142) in the doors, and Rockford-Fosgate 6X9 (R1692) behind the seats. This is in a 1980 MGB. The amp is in the trunk. Everything is wired in (speakers wired directly to the amp), but the fade and balance are out of whack. So, which channels are the front speakers supposed to connected to, and which to the rear? And the cables from the head unit (front and rear) connect to which channels on the amp? I haven't been able to find a diagram or clear-cut instructions. Other than the fade/balance issues (left rear sound coming from right front, for instance) the sound of the components is excellent. Thanks

  • Buck Pomerantz from Crutchfield

    Posted on 10/24/2016

    CJ, Not knowing exactly what subwoofers you have make it impossible to give advice on what amp to use. I can say that a car audio amplifier would be inappropriate for use in the home, needing an expensive high-current 12-volt power supply in order to work. Maybe you should check out a Pro Audio Amplifier to run your subs.

  • CJ from Springfield

    Posted on 10/23/2016

    I'm looking to have 2 15' subwoofers hooked up in my room and I would like the amp to run off of wall power. I was wondering if I can run an amp from wall power to my subs in my room so I can have high quality music in my room. My sister has a 4,000 watt amp will that blow my speakers or will that help them hit harder? I'm looking for an amp to wire the subs to and possibly add more in the future.

  • Buck Pomerantz from Crutchfield

    Posted on 10/6/2016

    Eric, The size of a speaker wire should be determined by how much power it needs to pass and how long it needs to be. For a subwoofer in a car audio application, 16-, 14-, or 12-gauge wire will all work just fine.

  • Eric from Prior lake

    Posted on 10/6/2016

    How do I determine what gauge of speaker wire to run in my setup if the woofer is 2dvc 4ohm 2000 watt peak ?

  • Buck Pomerantz from Crutchfield

    Posted on 9/26/2016

    Cooper, The specs you've given are a bit confusing. Two SVC 4-ohm subs wired together will only be 8 ohms if they were wired in series, and you probably don't want to do that. Not knowing exactly which subwoofers you have make it impossible to give accurate advice on which amp to use. If you want a question answered about your system, you must identify your equipment by model numbers as well as brand names. I will tell you that if you have two SVC (single voice coil) 4-ohm subs rated for 200 watts RMS each, you'd look for an amplifier that can put out between 300 and 600 watts RMS at 2 ohms, like a Kenwood KAC-5001PS 500-watt amplifier.

  • Cooper from Clifton Park

    Posted on 9/25/2016

    Hey there I just bought two Kenwood subwoofers 1600w max 800w each max 400rms total 200rms each 8 Ohms total 4 ohms each and I am having trouble choosing a proper amp. What is an adequate amp that will provide enough power for both of these subwoofers without overpowering or underpowering them?

  • Buck Pomerantz from Crutchfield

    Posted on 9/23/2016

    Adam, Knowing precisely what make and model amp you're getting would help, and alternators are usually rated in amperes, not watts. But if your alternator is really 70-amps, then about 35-amps would be available for aftermarket equipment, which would support a 500-watt amplifier at best. As for your vehicle's ECU and a high-output alternator, you'll have to ask an automotive specialist familiar with your specific vehicle about that.

  • Adam Brown from Myrtle Beach

    Posted on 9/23/2016

    Alright this is my deciding vote, and I know you guys are the some of the best in the business. I am getting an amp that is 1500 watts RMS @ 1 ohm and my alternator is only rated for 70 watts. Should I get a bigger alternator, and if I get a bigger alternator will it mess up my ECU?

  • Buck Pomerantz from Crutchfield

    Posted on 9/14/2016

    Matt, You could connect two speakers to a channel of your amp (using speaker wire not RCA cables), but you'd lose the ability to control the volume of each speaker separately, the front-to-rear fade control, and the power from the amp will get split in half by driving two speakers. The best way to power six speakers and a sub is with 7 channels of amplification.

  • Matt from Syracuse

    Posted on 9/13/2016

    I have 2 speakers in the front doors, two 4 inch speakers I put in the dash tweeter spots, 2 speakers in the rear doors and a sub in the back of my SUV. How can I power all of these wit one 5 channel amp? I was thinking about using a y shaped RCA cable to connect the back door and dash speakers to 2 channels, front speakers to 2 channels and the last channel to the sub?

  • Buck Pomerantz from Crutchfield

    Posted on 9/13/2016

    Chris, Please ignore all "peak power" ratings - they are meaningless. Use only RMS power ratings. If you want to power your 100 watts RMS rated speakers at their highest level just short of blowing, get a 4-channel amp that can put out 150 watts RMS per channel at 4 ohms, like an Alpine PDX-F6. It takes a 4-channel amplifier to drive 4 speakers, one speaker per channel.

  • Chris from Becker

    Posted on 9/12/2016

    I am looking at purchasing 4 new kicker speakers for my car. The speakers have a 300watt peak power and 100 watt rms. I am trying to figure out what amp to use to get full power and the best sound quality from the speakers. I will be keeping my factory head unit. But I am a bit confused on using a 4 channel amp or a 2 channel amp and how much wattage I need for max power. Thanks

  • Buck Pomerantz from Crutchfield

    Posted on 9/7/2016

    Joe, In this case, one sub per amp looks best. For power, you'd run one fused (100A) 2- to 4-gauge wire from the battery to a distribution block. Then run fused (50A each) 4-gauge power wire to each amp. For signal, you can run RCAs to one amp and daisy-chain its preamp output to the other amp's input. If those subs are the DVC 4-ohm models, you should wire each to its amp like this.

  • Joe anthony from Coronado

    Posted on 9/7/2016

    I currently have a jl slash 500/1 and a jl Jx 500/1d mono amps. I want to run both of them to power 2 jl w6 subwoofers. How would you recommend me wiring this set up? Independently? 1 amp run 1 and the other to the second sub? If so how would I do this?

  • Buck Pomerantz from Crutchfield

    Posted on 8/19/2016

    Andre, Typically, an amplifier, or amplifiers, with a total output of up to about 750 watts RMS will not stress a car's electrical system. Any larger, however, and electrical upgrades may become necessary.

  • Andre Letourneau from Brighton

    Posted on 8/19/2016

    I was just wondering how powerful of an amplifier I can use on my stock battery and alternator? I'm driving a Pontiac G5 2009

  • Buck Pomerantz from Crutchfield

    Posted on 7/25/2016

    Michael, I can't recommend a setup for gear I'm unfamiliar with which Crutchfield doesn't carry. I can't tell if those subs are DVC or SVC models. I did find that amp's power specs - 200 watts RMS at 4 ohms, 400 at 2 ohms, and 600 at one ohm - but I'm not at all confident that it will be able to actually produce that much power.

  • Michael from Kennett

    Posted on 7/22/2016

    I have pair of Phoenix gold r3 10" 400w 800w max 4ohm speakers and a Phoenix gold sd600.1 it's rated at 600w 2ohm. Would it be better to put a different amp either more watts or higher ohms. This amp doesn't show a rating for 4ohms just 1&2ohm

  • Buck Pomerantz from Crutchfield

    Posted on 7/21/2016

    Deslie, Most car electrical systems can handle the draw of 600 watts RMS worth of aftermarket amplifiers.

  • Deslie Greenaway from Atlanta

    Posted on 7/21/2016

    Can i install two powered subs (300 watts each) in my car?? would that use up too much power or over work the alternator?

  • Buck Pomerantz from Crutchfield

    Posted on 7/12/2016

    William, Not knowing exactly what amplifiers, speakers, or subwoofers you have, or how they're wired together make it impossible to give advice on what may be wrong. If you want a question answered about your system, you must identify the equipment by brand names and model numbers, and, in your case, how they're connected.

  • william from clarksville tn

    Posted on 7/11/2016

    hello I took my system out of one vehicle and installed it to an other, no big deal my amp for my 6*9s and speakers work but cut out if I turn up to loud. and now my amp for my subs is in protect mode please help everything worked fine before.

  • Buck Pomerantz from Crutchfield

    Posted on 6/17/2016

    Ron, Three DVC 2-ohm subs get wired to a mono amp capable of driving a 1-ohm load like this.

  • Ron robinson from Belton

    Posted on 6/17/2016

    What happens when you hook up a single15in dvc 2ohm wired to 1ohm load and 2 12in dvc 2ohm wired to 2ohm load to the same mono block 1ohm stable amplifier?

  • Buck Pomerantz from Crutchfield

    Posted on 6/10/2016

    Joshua, You have a real fire hazard in your vehicle: In the event of a short circuit, your 4-gauge wire and car will catch fire and burn before that 175-A fuse will. 4-gauge wire should not be fused higher than about 100-A. And that Sundowner amp needs 1/0-gauge power and ground wiring.

  • Joshua Carmona from Ruskin

    Posted on 6/9/2016

    Hello I have a question, I have a EMF 12" 2000RMS subwoofer wired to 1ohm and I just had stinger 4 gauge 6000 series installed with a 175 amp fuse. And I have a hifonics zeus 2400watt 1200rms amp to it but was thinking of buying another amp like the sundown scv 2000d for the emf sub can my 4 gauge with 175 amp fuse handle the sundown amp? I don't want anything burning up if it can't handle the amplifier.

  • Buck Pomerantz from Crutchfield

    Posted on 6/1/2016

    Joqi, You can drive four speakers and a subwoofer with a 4-channel amplifier by A: wire your left and right speaker pairs together in parallel (positive-to-positive etc.), and to a front channel of the amp. B: bridge the rear amp channels together to drive the sub. That gets all your speakers and sub going without needing to buy a sub amp, but you'll lose the ability to fade the music from front to rear. You also may find that the bridged channels don't produce enough power for strong bass.

  • Buck Pomerantz from Crutchfield

    Posted on 6/1/2016

    Ted, If you're asking if an amplifier's preamp outputs are live when the amp is turned off, then the answer is probably not. The output gets the signal from the adjacent input, but usually by way of a buffer circuit that needs power to work.

  • Joji Johnson

    Posted on 5/31/2016

    Buck, Recently I have Purchased Pioneer D8604 4 channel Amp and TSSX2502 Shallow Sub for my Hyundai,, Present Head Unit Pioneer AVHX2750BT, Front Door Speakers: Pioneer TS-R1650S - 40Watt Nom 250 Watt Max, Rear Door Speakers: Pioneer TS-A1685S - 60 Nom 350 Watt Max, My Question How can I run all of this including New Sub with D8604 4 channel amp? Wish to have your valuable Suggestion on above.

  • Ted

    Posted on 5/30/2016

    I'd like to get a signal to amp #2 by connecting to amp #1. Will amp #2 get the signal if amp #1 is not turned on?

  • Buck Pomerantz from Crutchfield

    Posted on 5/23/2016

    Steven, It sounds like you've got two pairs of subs and speakers wired together in parallel and also to the outputs of your receiver and sub amp all at the same time. This could damage your gear. Normally, when you want to add a subwoofer to a factory system, you use a line output converter (LOC) connected to the factory speaker wiring. Then you'd connect, via RCA cables, the LOC to the sub amp's inputs. Then you'd run speaker wires from the amp's outputs to your subwoofers. If your sub amp has speaker-level inputs, you won't need an LOC, you'd run speaker wires directly to the amp's inputs.

  • Steven Martin from San Antonio

    Posted on 5/23/2016

    Im trying to wire my subs into my factory 6x9s ive tied the wires from the 6x9s together with speaker wire that goes into the subs then another run of speaker wire from the subs to the amp and a remote jumper ive done it be4 and it worked pls tell me what im doing wrong

  • Buck Pomerantz from Crutchfield

    Posted on 5/16/2016

    Rafael, That amplifier's specs call for 4-gauge power and ground wiring, but using 0-gauge won't hurt anything. Nor will using a second battery. And your sub should be safe being run by that amp as long as you don't play distorted signals in attempts to get louder bass.

  • Rafael from Houston

    Posted on 5/13/2016

    I'm running an jx1000/1d amp (1000 watt RMS) with two 12" Polk audio Db1222 subwoofers rated (720 watts RMS). Also connected two a second battery with 0/gauge wire to amp. Would you say this is a good idea and can it harm my subs? Or should the subs still be able to handle it?

  • Buck Pomerantz from Crutchfield

    Posted on 5/10/2016

    Isaac, Have you tried taming the brightness and distortion by adjusting your receiver's tone controls and the amplifier's filters and boost? Amplifiers usually do not by themselves affect tone, and play distortion only when either over-driven or fed distorted signals to begin with.

  • Issac Lopez from Northglenn

    Posted on 5/10/2016

    Do amps have a big factor on sound quality, I have a pair of infinity kappa component that are really bright and distorting I was told that the low end rockford amp I'm using should be replaced for a higher end amp.

  • Buck Pomerantz from Crutchfield

    Posted on 5/2/2016

    Frank, If you can't achieve the tune you want using the tone controls available, maybe you should look into adding an equalizer to your system, like an AudioControl EQL, in order to tame those out-of-control frequencies.

  • Frank from Orlando

    Posted on 4/29/2016

    I recently added two amps one for my subs and one for my front door 2 way 6x9 speakers. I'm having trouble getting them to sound good I've adjusted the treble and bass as well as amp setting and i just can't seem to make the treble not be ear piercing can ou help I have a kicker zx 350x4

  • Buck Pomerantz from Crutchfield

    Posted on 3/4/2016

    Valdosta, If you are running one amplifier that has 140 amps worth of fusing, you will need large enough power wire to support its current draw (4-ga. for a short run, 1/0-ga. for longer), and a fuse near the battery (140 amps or whatever the wire manufacturer rates their wire). Amplifier wiring kits are the most convenient way to get an amp wired up with all the right parts included.

  • Valdosta from Portland

    Posted on 3/3/2016

    What if my amp has 2 70amp fuses Do I need a 140amp fuse at the battery or 70amp If 70 can I use a 80amp fuse?

  • Buck Pomerantz from Crutchfield

    Posted on 2/3/2016

    Wes, First of all, under no circumstances should you ever mount an amplifier under a carpet. An amplifier needs some open air space around it to dissipate the heat that builds up as it works, otherwise it will overheat and shut down. That also means that dirt, crumbs, water, and other contaminants need to get cleaned off an amp if you want it to work properly and reliably. If you can't do that with an amp mounted under a seat, choose another location for it.

  • Wes Yarber from Tupelo

    Posted on 2/2/2016

    I am readying to do my full install within a few days. My amplifier should be arriving in 2 or 3 days. I'm trying to prep now so I can get to work when my amplifier comes in. I'm stumped on where to mount my components. I have a 4 channel amp for my front a rear speakers, a 2 channel amp to drive my subwoofers, and an LCQ-1 because i'm using my stock headunit. I'm installing into a 2015 4runner trail am installing this system to hopefully last upwards of 15 years without having to replace anything for it overheating or getting crums and dust in it. I saw you recommended under the seats. I did a test where I left my LCQ under my driver's seat for a few months. When i took it out, crums had gotten in between the knobs and enclosure and then inside the device. I'm concerned with that being an issue so I think to myself, what If i mounted it under the carpet? I would probably have to mojnt under both the driver and passenger's seats because of the space I have. Then there seems to be an overheating issue due to the lack of airflow. I've been scratching my head at this for a while and am desperate for ideas. do you have any insught or advice on where to put everything?

  • Buck Pomerantz from Crutchfield

    Posted on 1/15/2016

    Brendan, Thanks for the kind words. Unfortunately, we're only licensed to sell gear in the United States and Canada. Sorry.

  • Brendan from Brisbane

    Posted on 1/14/2016

    G'day Buck Do Crutchfield have any Aussie store's ? If not does Crutchfield have plans to expand to oversea's market's ? Great site extremely informative. Cheers.

  • Buck Pomerantz from Crutchfield

    Posted on 1/13/2016

    Brian, You should first check the wiring and correct any shorts or loose connections. Some line output converters have level controls and yours may be set wrong. Or your amplifier's gain isn't adjusted correctly. If you bought any of your gear from Crutchfield, you could call Tech Support for free help troubleshooting your system. Their toll-free number is on your invoice. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Click on this link for details.

  • Brian from San Antonio

    Posted on 1/12/2016

    I bought a 2 ch line output converter to add my system to my new car. I ran my 4 gauge power line w/ a 150Amp fuse to the rear where it attaches to my JL 1000.1 and two Alpine type R 12''s. I tapped off the left and right rear speakers but I am getting little to no joy out of the subwoofers. As in nothing at all. Amp lights are all on, etc. Any ideas?

  • Brett from Waco

    Posted on 12/3/2015

    I have a four door lariat Ford F-250 (truck) but very limited space, I want to put some subs in but don't know what size and how to wire, and I need the back seats open

  • Buck Pomerantz from Crutchfield

    Posted on 10/7/2015

    Fasihuddin, I'm sorry I haven't answered your question sooner. If you're asking about the differences in amplifier strength, then it all has to do with how loud people listen to their music, and how amplifier manufacturers respond to their customers' wants and needs.

  • Fasihuddin from Karachi

    Posted on 9/10/2015

    What makes the size variation in car amplifier?

  • Buck Pomerantz from Crutchfield

    Posted on 9/9/2015

    Todd, Are you asking about an amplifier's 12-volt remote turn-on connection or a subwoofer amp's remote level control? If you bought your amp from Crutchfield, you could call Tech Support for free help troubleshooting your system. Their toll-free number is on your invoice. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Click on this link for details.

  • Todd Jackson from Youngstown

    Posted on 9/8/2015

    My remote is bad on the amp connection what can I do

  • Buck Pomerantz from Crutchfield

    Posted on 8/31/2015

    Clint, The in-line fuse that comes with the wiring kit is there to protect the power wire and your car in the event of a short circuit. The manufacturer decides what size fuse will protect the wire. If your amplifier doesn't have an onboard fuse, it might be a good idea to add that recommended fuse near the amp to protect it.

  • Clint Hughes from Houston

    Posted on 8/30/2015

    The amp I am buying suggests a 60 amp fuse and 4ga wiring and the wiring kit I'm buying comes with a 100amp fuse and 4ga wire. Do I need to get a smaller fuse to match the requirements?

  • Buck Pomerantz from Crutchfield

    Posted on 8/12/2015

    Binyamin, Every 5-channel amplifier that I've encountered can handle driving 4-ohm speakers along with a 2-ohm sub. So unless the amp's specs and literature say otherwise, you will be alright hooking it up that way.

  • Binyamin from Jerusalem

    Posted on 8/12/2015

    If I get a 5 channel amp, do all of the speakers have to be at the same impedance? Meaning would I be able to get 4 channels on 4ohms and the sub on 2?

  • Buck Pomerantz from Crutchfield

    Posted on 8/4/2015

    Christiaan, The way subwoofers are wired together and to amplifiers greatly affects their output power. Not knowing what gear you have nor how it was wired together makes it impossible to say what caused the change in volume.

  • christiaan mitchell from Tampa

    Posted on 8/3/2015

    I have 4 subwoofers. Two amps until I sold one of them now I'm only using one amp. Why is it that my subwoofers sound louder with one amp then when I had two of the same ampliers hooked up?

  • Buck Pomerantz from Crutchfield

    Posted on 7/29/2015

    Jason, It sure would. Wire your gear together like this.

  • Jason from Sellers

    Posted on 7/29/2015

    I have 2 dvc 2 ohm 15's that are 1000w rms a piece, would it be a good idea to run them at a 2 ohm load @ 2000w on a monoblock amp?

  • Buck Pomerantz from Crutchfield

    Posted on 7/21/2015

    Peter, Car amplifiers have a remote turn-on lead connection that should go to a source of 12 volts that turns off when the car is off, so the amp won't run the car battery dead. It sounds like you have yours connected to a constant power source and it killed your battery. If you can't find a switched source of power you can install a switch on your remote lead so you can turn your amp off when you want.

  • Peter Leal from las Vegas

    Posted on 7/20/2015

    I just installed my amp using the stock radio. Used a rca converter and connected to speaker wires, amp works and sound is coming now i shut my car off and radio stays on, and my car won't start. Help please !!

  • Buck Pomerantz from Crutchfield

    Posted on 6/22/2015

    Geovanny, Speakers rated for 60 watts RMS will easily handle 75 watts. And if you can wire the subs together to present the amp a 4-ohm load, they can take the amp's full power easily as well. However, you need to properly set your amplifiers' gains, not at their minimums. Check out "How do I fine-tune my amplifier's gain and bass boost settings?" in this article, just above the Comment section, for help doing that.

  • Geovanny from Venezuela

    Posted on 6/19/2015

    What will happen if I connect 60 RMS (110MAX) 4" speakers to an amp with 75 RMS output per channel at 4ohm? and 2 sub 8" 150 RMS (300MAX) in parallel to a mono amp with 300 RMS at 4ohm output? keeping in both amp the gain to minimum. Thanks.

  • Buck Pomerantz from Crutchfield

    Posted on 6/15/2015

    Steve, If your amplifier can put out 100 watts RMS to four speakers (400 watts RMS total) and you don't plan on adding a subwoofer amp in the future, I recommend using 4-gauge power and ground wiring. I also recommend using the battery negative terminal as your grounding point - I think in the marine environment it's a more reliable connection than the engine block.

  • Steve Scovell from Columbus, Ohio

    Posted on 6/14/2015

    Just installed a new amp receiver and speaker combination in my boat. My question has to do with supply power cable size and grounding location. My amp is 4 channel putting out 100 watts per and my speakers (4) are 200 watt RMS. I currently have a power run of approximately 18 feet from batteries to AMP. With a fiberglass boat the only suitable grounding locations are either the motor block or the battery itself. I wish to know: 1 - the size wire i should be using for power supply to amp 2 - pros/cons or grounding directly to the battery Thanks for your help!

  • Buck Pomerantz from Crutchfield

    Posted on 6/8/2015

    Jorge, You're right - my comment to Dustin was a bit broad in scope, but I did qualify it with "generally speaking." There are a few exceptions, but the vast majority of 2-channel amps can't drive loads lower than 4 ohms when bridged, and don't have enough power to drive more than one sub. Mono, 1-channel amplifiers are designed to work with a wider range of impedances, and have tone controls and filters specifically made to help reproduce bass through a subwoofer. That's why I always recommend using a subwoofer amplifier to power subwoofers.

  • Jorge from righthere

    Posted on 6/6/2015

    The comment below that "a 2 ch amp is inappropriate for driving a subwoofer ", is completely false and documented by millions of people and hundreds of audio component manufacturers. I don't know what Buck was thinking but he answered the question incorrectly.

  • Buck Pomerantz from Crutchfield

    Posted on 6/1/2015

    Dustin, It depends on which specific amp and which specific sub. Generally speaking, a 2-channel amp is inappropriate for driving a subwoofer.

  • dustin from tulsa

    Posted on 5/31/2015

    can a 1200w 2ch amp power up a 2500w subwoofer briged

  • Buck Pomerantz from Crutchfield

    Posted on 5/28/2015

    Steven, A 4-channel amplifier can get connected a lot of different ways. You can connect the left front and rear speakers to one channel, and the right front and rear speakers to a second channel, and bridge the other two channels to run a subwoofer. You'd lose the stereo's front-to-rear fade function, but you may not care about that. Most people in this situation would use two channels to drive the front speakers, bridge the other two for a sub, and leave the rear speakers connected to the receiver for the rear-fill sound. But if you like the sound coming from the rear, go ahead and amp the rear speakers instead.

  • Steven Torres from Hemet CA

    Posted on 5/28/2015

    Can i connect a 4 channel amp to two rear speakers two front speakers and a sub? if not can i just connect a sub and the rear speakers and have the front speakers still working even if they're not connected?