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How to match subwoofers and amplifiers

Find the right amp for your sub or sub for your amp

How to match subs and amps

The secret to great bass is making sure your subwoofers and amp are evenly matched and will properly work together. And this article will help you figure out how to do just that — match amplifiers and subwoofers.

Getting the right sub for an amp, or the right amp for a sub, is like solving a puzzle. A subwoofer has impedance (measured in ohms) which represents the "load" an amplifier will sense on its output. An amplifier will put out different amounts of power (watts RMS) based on the impedance load it "sees."

Solving the puzzle

The amplifier's capabilities (X watts RMS into Y ohms) needs to match the subwoofer's specifications (Y ohms and can handle X watts RMS). Your goal is to get those two variables to match for both the amplifier and the subwoofer.

Below, we cover the important basics of power-matching, impedance, and planning for the number of subs you want, and we approach the situation from both sides of the system:

  • Part A: You have the subs, which amp should you get?
  • Part B: You have the amp, which subs should you get?
  • And also, Part C: You have neither amp nor sub, and want help deciding how to begin.

Start with either part of this article you want, but A and B are both worth a read.


Part A — You have the subs, which amplifier should you get?

The subwoofers need to be the same

Multiple subs wired together must be the same coil type and impedance. If they’re not, the power won’t divide evenly between them, and some subs would probably be over-powered while others get under-powered. If you want to run different types of subs in a system, each type needs to have its own separate amp.

Step 1: How much power? Find out the “watts RMS” rating of the sub

Then, multiply the number of subs you have by the RMS rating of each, to get their total RMS rating. You want to make sure the amp you choose will supply no more than the sub system’s total RMS rating.

Step 2: What impedance? The results of combining coils and subs

Figure out the possible total impedance(s) that the subs can be wired together to form.
SVC = A subwoofer with a single voice coil. It has only one pair of terminals.
DVC = A subwoofer with a dual voice coil. It has two pairs of terminals.

  • 1 SVC 2-ohm sub can only have 2 ohms of impedance
  • 1 SVC 4-ohm sub can only have 4 ohms of impedance
  • 1 DVC 2-ohm sub can have 1 ohm or 4 ohms of impedance
  • 1 DVC 4-ohm sub can have 2 ohms or 8 ohms of impedance
  • 2 SVC 2-ohm subs can have 1 ohm or 4 ohms of impedance
  • 2 SVC 4-ohm subs can have 2 ohms or 8 ohms of impedance
  • 2 DVC 2-ohm subs can have 1/2 ohm, 2 ohms, or 8 ohms of impedance
  • 2 DVC 4-ohm subs can have 1 ohm4 ohms, or 16 ohms of impedance

For more combinations of subs and their impedances, see Subwoofer Wiring Diagrams.

Step 3: Pick an amp that can do both — X watts at Y ohms

Look for an amplifier that can put out power up to the RMS wattage you’ve figured in Step 1, at an impedance load the subs can be wired to form, from Step 2.

Estimating amp power at the odd impedance values:

  • 8 ohms — figure on the amp putting out half the power it would at 4 ohms
  • 6 ohms — figure on the amp putting out three-quarters of the power it would at 4 ohms
  • 3 ohms — figure on the amp putting out the average of what it would at 2 ohms and at 4 ohms
  • 2.7 ohms — figure the same as for 3 ohms, and add a few watts
  • 1.3 ohms — use the 1-ohm spec and take away a few watts
Alpine S-W8D4

Example: Finding an amp for your subs
You have two Alpine S Series S-W8D4 8" subwoofers and you want the right amp for them.

They are DVC 4-ohm subs rated at 300 watts RMS each.

Two 300 watts RMS subs together need a maximum total of 600 watts RMS.

Using the chart in Step 2, 2 DVC 4-ohm subs can be wired together to form a 1-ohm, a 4-ohm, or a 16-ohm load.

The last is too high a load to be practical, so you’ll look for an amp that can put out up to 600 watts RMS into either a 4-ohm load, or a 1-ohm impedance load:

  • up to 600 watts RMS x 1 at 4 ohms, or
  • up to 600 watts RMS x 1 at 1 ohm

Among Crutchfield’s selection of amplifiers you’ll find:

Any one of these high-quality amplifiers would work well with those subs. It doesn’t matter which impedance an amp plays through — 600 watts RMS through a 4-ohm load produces the same volume as 600 watts RMS through a 1-ohm load.

JL Audio JD1000/1

JL Audio JD1000/1 subwoofer amplifier


Kicker KEY500.1

Kicker KEY500.1 subwoofer amplifier

Part B — You have the amplfier, which subs should you get?

Step 1: What can the amp do? Find the RMS power ratings of the amp at different loads

Find the amp’s power, expressed in “watts RMS”, at 4 ohms, at 2 ohms, and, if it can, at 1 ohm. Pick the power you’d like to achieve. The load impedance (ohms) of that rating will be what you want your subs’ total impedance to be.

Step 2: How many subs do you want?

Divide the power you picked in Step 1 by the number of subs you want. This number is the target RMS rating for each of the subs you’ll choose. 

Step 3: What impedance does each sub need to be and how many voice coils?

Using the impedance you picked in Step 1 and the number of subs from Step 2, cross-reference the possible coil configurations that you can use: 

1-ohm 2-ohms 4-ohms
1 sub DVC 2-ohms SVC 2-ohms
DVC 4 ohms
SVC 4-ohms
DVC 2-ohms
2 subs SVC 2-ohms
DVC 4-ohms
SVC 4-ohms
DVC 2-ohms
SVC 2-ohms
DVC 4-ohms
3 subs (1.3 ohms)*
SVC 4-ohms
DVC 2-ohms
(3 or 2.7 ohms)*
DVC 2-ohms
DVC 4-ohms
(6 ohms)*
SVC 2-ohms
DVC 4-ohms
4 subs SVC 4-ohms
DVC 2-ohms
SVC 2-ohms
DVC 4 ohms
SVC 4-ohms
DVC 2-ohms
* Estimate amp power at the odd impedance values like in Part A, Step 3, above.

Step 4: Pick a sub that works for both — (SVC or DVC) X-ohms, Y watts RMS)

Look for subs that are rated at the wattage you figured in Step 2, and are configured as you found in Step 3. This might sound confusing, so let's walk through an example and it'll make sense.

JL Audio JD500/1

Example: Finding subs for your amplifier
You have a JL Audio JD500/1 amplifier and you want it to drive two subwoofers

The amp is capable of 250 watts RMS x 1 at 4 ohms and 500 watts RMS x 1 at 2 ohms.

Let’s say you choose to maximize the amp’s potential and want the system to put out 500 watts RMS. This means your subs have to be wired to form a total impedance of 2 ohms.

Two subs on a 500 watts RMS amp will want about 250 watts RMS each.
So you’ll look for subs each rated for 250 watts RMS or more.

Using the chart in Step 3, for two subwoofers, a final 2-ohm load can be achieved with either two SVC 4-ohm subs or two DVC 2-ohm subs.

So, you’ll look for two subs that are either SVC 4-ohms or DVC 2-ohms, rated for at least 250 watts RMS each:

  • 2 SVC 4-ohms, at least 250 watts RMS, or
  • 2 DVC 2-ohms, at least 250 watts RMS

Among Crutchfield’s selection of subwoofers you’ll find:

Kicker CompC 10"

Kicker CompC 10" component subwoofer

All these subwoofers will sound their best when amplified with the proper amount of power. Differences in size have more to do with tonal qualities and frequency response than with power performance. And optimizing performance is the point of matching subs and amps together.


Part C — You have neither amp nor sub, and want help deciding how to begin

Check out our other article, All About Subwoofers to learn the basics of how much bass you need and how to choose your subwoofers. 

And of course, if you have any questions, contact our expert advisors and they'll be happy to help you build your system. 

  • KATIE from Chattanooga

    Posted on 1/23/2023

    I bought a 10" JBL stage sub with a 900 watt output @ 225 RMS. Would you please recommend an amplifier? TY

    Commenter image

    Buck Pomerantz from Crutchfield

    on 1/23/2023

    Katie, That SVC 4-ohm sub rated for 225 watts RMS (you should never use peak ratings for system designing) will work great with an amplifier that can put out up to 225 watts RMS at 4-ohms, like a Kenwood KAC-M3001. Give us a call so an Advisor can help you get everything you need (sub, amp, box, and wiring) for a successful subwoofer installation.
  • Roy Strickland from Johnson City, Tn

    Posted on 1/10/2023

    I've got two 4 ohm 300 rms 10" Kickers and a mono 1600 watt Pioneer amp that gives 500 watts at 2 ohms, if I wire them parallel will that give 500 watts to each or 250 watts each?

    Commenter image

    Buck Pomerantz from Crutchfield

    on 1/11/2023

    Roy, Two same-model subs (same impedance, number of coils, and sensitivity) wired correctly, in series or parallel, to an amplifier will absorb and dissipate the available power evenly - half the total to each. In your example, the amp will send each sub 250 watts.
  • Mike Henn from Chino Hills

    Posted on 1/9/2023

    Hi Buck. I just set up a budget kenwood sub/amp package from BestBuy and I'm pretty underwhelmed by the performance. It's currently set up as two 12's in an enclosed box to a single class D mono amp. I would like your opinion if it would sound better to just run 12 instead. Thanks Speakers: 2 Kenwood SVC 12 subs RMS 250 @ 4ohms (KFC-W120 SVC) Amp: Kenwood Class D mono amp RMS 300 @ 4ohms or 500 @ 2ohms

    Commenter image

    Buck Pomerantz from Crutchfield

    on 1/10/2023

    Mike, Either 500 watts worth of bass isn't enough for you or the two subs aren't wired together properly in order to produce that 500 watts. If you had bought your gear from Crutchfield, you could call Tech Support for free help troubleshooting your system.
  • Rhyse Messenger from Mount Vernon, WA

    Posted on 1/6/2023

    Hello looking to buy 2) 12" JL Audio 12W1v3-4. I need to know what amplifier would work for them. They are 300 watt rms at 4ohms each. Thank you!

    Commenter image

    Buck Pomerantz from Crutchfield

    on 1/9/2023

    Rhyse, Those two SVC 4-ohm subs rated for 00 watts RMS each will work well with an amplifier that can send them up to 600 watts RMS at 2-ohms, like anAlpine S-A60M
  • William from Texas

    Posted on 1/5/2023

    Rockford fosgate punch P1 2x12 ported ! What would be a good amp to push these?

    Commenter image

    Buck Pomerantz from Crutchfield

    on 1/6/2023

    William, That 2-ohm 500 watts RMS rated sub will work well with an amp that can put out up to 500 watts RMS at 2-ohms, like a Rockford Fosgate R2-500X1
  • Blan Newcomb from Jackson

    Posted on 12/23/2022

    I have a Rockford Fosgate T1500 DB1 would it be compatible with Memphis Audio mini mojos dual 8in enclosure MJME8D1

    Commenter image

    Buck Pomerantz from Crutchfield

    on 12/26/2022

    Blan, That amp and sub should work swell together.
  • Cliff from Stony point

    Posted on 12/11/2022

    What is a good amp for kicker 46cwtb104-rs, 400 rms at 4 ohms and 800 max? Need a marine amp, will be going on a boat.

    Commenter image

    Buck Pomerantz from Crutchfield

    on 12/12/2022

    Cliff, That 4-ohm sub rated for 400 watts RMS will work great with an amplifier that can put out up to 400 watts RMS at 4-ohms, like a Roswell 1000.1 .
  • Paul Klingensmith from Wewahitchka

    Posted on 12/10/2022

    I have a Rockford Fosgate R2-1200X1 running a Skar Audio Single 12" 2500W EVL-1X12D2. Will I have a problems??

    Commenter image

    Buck Pomerantz from Crutchfield

    on 12/10/2022

    Paul, That sub, pre-wired to be 1-ohm and rated for 1250 watts RMS will work great with that amplifier which can send it 1200 watts at 1-ohm.
  • Alan beede from Johnstown

    Posted on 12/10/2022

    I have 3 10-inch subs 400 w max,,200 w rms...whats the best amp for these subs..and how should the be wired, series or parallel or? I just want 1 amp for the 3 subs..Thanks,Alan

    Commenter image

    Buck Pomerantz from Crutchfield

    on 12/10/2022

    Alan, Without knowing precisely what subs you're referring to, we can't help you with advice. (Are they SVC or DVC; 2-ohm or 4-ohm?) 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.
  • Prabin from Salalah

    Posted on 11/28/2022

    I have a JVC cs-dx120 sub. Please advise me for buy an amplifier

    Commenter image

    Buck Pomerantz from Crutchfield

    on 11/29/2022

    Prabin, That DVC 4-ohm sub rated for 700 watts RMS will work best with an amplifier that can put out up to 700 watts RMS at 2-ohms. I can't give you a more detailed recommendation because I don't know what products are available in your country.

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