Answers to questions about EQ
AudioControl EQS 6-channel 13-band equalizer
Q: How can an equalizer help my car audio system?
A: When you ask other car stereo fans whether you need to add an equalizer (EQ) to your system, you may get a shorthand response dismissing this component as an elaborate tone control. While it's true that people who can't seem to stop twiddling with their bass and treble knobs tend to love the precise tone shaping capabilities an equalizer affords, there's a bit more to the story. When you know how to use it, a quality EQ will let you compensate for the noisiest component in your system — your car.
Most vehicles have a natural resonant frequency between 100 and 200 HZ, so even an otherwise perfectly balanced system can seem to get a bump at these frequencies, exaggerating them in a way that can muddy your sound. With a graphic EQ, it's easy for you to reach out and clean up your sound by cutting the offending bandwidths and boosting those frequencies that would otherwise be masked. Similarly, an EQ will also let you compensate for the road noise that typically masks music between 25 and 200 Hz.
An EQ can also help you adjust for the acoustic properties of the materials found inside your vehicle. The glass in your car, a highly reflective surface, can overemphasize highs and make for a particularly "live" (reverberation-heavy) sound. On the other hand, the definition or "crispness" of your entire system can easily be dulled by absorbent surfaces like your car or truck's carpeted interior. You can use an equalizer to remedy each one of these ills, boosting the frequencies you're missing and attenuating the ones your vehicle exaggerates. When you make these adjustments, try to use a light touch on those EQ adjustments — a boost of 10 dB works your amplifier ten times harder, and this can introduce distortion.
While recent years have seen a drop-off in the popularity of stand-alone, dash-mounted EQs, the desire to tweak one's response curve continues unabated. It's just that the latest generations of car audio gear tend to package this capability a little differently.
A number of in-dash receivers now offer features ranging from a few customizable tone curves to elaborate built-in digital parametric equalizers, crossover networks, Digital Signal Processors and spectrum analyzers. Once you sample the flavors components like these add to the menu, you may find it hard to ever settle for plain vanilla again. The good news is you don't have to.
Q: How does an equalizer differ from a crossover?
A: Because they both affect your system's frequency response, crossovers and equalizers are often confused. A crossover is any device that limits the range of frequencies sent to a speaker or amplifier. By allowing you to choose which frequencies are sent to which of your speakers, a crossover network acts like an audio traffic cop, directing the appropriate frequencies to your mids, tweeters, and subwoofers.
While electronic crossovers also allow you to adjust the strength of the signal being sent to the various speakers, an equalizer lets you precisely cut and boost the output of multiple frequencies across a broad spectrum. You can think of an equalizer as giving you more immediate, hands-on control over the overall sound of your system.
Q: Where do I mount an equalizer?
A: You'll find two types of equalizers. Dash-mounted equalizers usually install above or below the receiver in the factory radio location, or they can also be mounted below the dash with a bracket or special kit. Trunk-mount equalizers install in a remote location (trunk, cargo area) next to your amplifiers.
Q: What's a spectrum analyzer and do I need one?
A: A spectrum analyzer, also known as a real-time analyzer (RTA), is an electronic device which measures and displays the frequency spectrum of an audio signal in real time. It uses a number of narrow bandwidth filters connected to a display to give a visual indication of the amplitude of each frequency band. A microphone, connected to the analyzer’s input, picks up the all-frequency pink noise you play through the system, and the RTA displays its response onscreen.
Obtaining an RTA can be as simple as downloading an app to your phone, and if you like to constantly tweak your system’s tuning, using one is a lot of fun. But unless you plan on participating in sound quality competitions, you probably don’t really need one. Your ears should tell you more about how your system sounds than any measurement device or display.
Q: Since I installed my EQ, my receiver's fader control won't work. Why not?
A: If your EQ only has one set of inputs, it receives a single stereo signal from your receiver, instead of separate signals for front and rear. That's why you've lost your fader. Many 2-channel equalizers offer a fader control, so you can still balance the music between the front and rear speakers.
If you want to keep your receiver's fader capability, you should use an equalizer that will accept all your receiver's preamp outputs. A 4-channel equalizer will accept your receiver's front and rear outputs. A 6-channel EQ will also accept your receiver's subwoofer outputs so you can still adjust your sub's level with your receiver's controls.
Q: What's the best setting for the EQ controls? My buddy says the best setting is to boost the lows and the highs and cut the mids.
A: While many people do like to boost the low and high frequencies, this setting may not sound the best in your system. The best way to determine the most appropriate EQ settings is trial and error. Your speakers and the inside of your car both come into play, as well as the type of music you typically listen to.
Start with all the sliders or knobs set flat, so that the EQ is not affecting your sound. Then, turn every control up and down to hear what part of the sound it effects. Make minor adjustments to the appropriate frequencies that are missing or are too strong until they sound right. For example, if your vocals are not coming through clearly, boost some of the middle frequencies a little.
Or maybe the vocals aren't clear because the highs are too piercing. In this case, attenuate some of the higher frequency bands a little. And instead of boosting the low frequencies all the way up (and we've all been tempted), try bringing them up just a little bit, while lowering the mids and highs a touch — you'll get more effective gain out of your system that way (and you won't fry your speakers). The great thing about having an equalizer is that you can change the sound of your music quickly and easily to match your mood.