Chat
Contact us
Close contact box
Connect ID #
514 261 847 3
Connect ID #
514 261 847 3
All finished with your chat session?

We’ll email you a transcript of this conversation for your records.

Our contact center is currently closed.

Please enter your name.  
Please enter a valid email address. Why is this required?
Please enter your US phone number.  

For Tech Support, call 1-888-292-2575

Thank you, !
Our conversation will be emailed to
Chat Advisor Image

Your Advisor,

More about me
Please enter a question  
Don't wait on hold. We'll call you back when it's your turn to talk with the next available .
Please enter your name  
Please enter your phone number  

Please enter a message  

Calls may be recorded for training and quality control purposes.

We are located in Virginia USA.

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 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 = single voice coil, 1 pair of terminals; DVC = dual voice coil, 2 pairs of terminals.)

  • 1 SVC 2-ohms can only have 2 ohms of impedance
  • 1 SVC 4-ohms can only have 4 ohms of impedance
  • 1 DVC 2-ohms can have 1 ohm or 4 ohms of impedance
  • 1 DVC 4-ohms can have 2 ohms or 8 ohms of impedance
  • 2 SVC 2-ohms can have 1 ohm or 4 ohms of impedance
  • 2 SVC 4-ohms can have 2 ohms or 8 ohms of impedance
  • 2 DVC 2-ohms can have 2 ohms or 8 ohms of impedance
  • 2 DVC 4-ohms can have 1 ohm or 4 ohms of impedance
  • 3 SVC 2-ohms can have 6 ohms of impedance
  • 3 SVC 4-ohms can have 1.3 ohms of impedance
  • 3 DVC 2-ohms can have 1.3 ohms or 3 ohms of impedance
  • 3 DVC 4-ohms can have 2.7 ohms or 6 ohms of impedance
  • 4 SVC 2-ohms can have 2 ohms or 8 ohms of impedance
  • 4 SVC 4-ohms can have 1 ohm or 4 ohms of impedance
  • 4 DVC 2-ohms can have 1 ohm or 4 ohms of impedance
  • 4 DVC 4-ohms can have 2 ohms or 8 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:
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 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.

Memphis Audio 16-SRX500D.1

Example:
You have a Memphis Audio SRX500D.1 amplifier and you want it to drive two subwoofers

The amp is capable of 350 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. 

  • MOON from SEOUL

    Posted on 1/18/2022

    Hello. I learned a lot through the this site. thank you. Amplifier: Alpine KTA-30MW Mono Tough Pack Amplifier *1 Power handling: 300 watts RMS x 1 at 2 ohms (600 watts max) Frequency Response: 20-400Hz Variable low-pass filter (50-400 Hz at 24 dB/octave) Woofer: kicker 48CWRT672 *2 (CompRT series shallow mount 6-3/4" subwoofer with dual 2 ohm voice coil) Power handling: 75-150 watts RMS (300 watts max) Frequency Response: 30-500Hz My car is a Jeep Wrangler JK 2017 and my plan to install the amp under the dashboard. The woofer I chose was small enough to fit into my Select Increments JKU-Pods. I learned from this site that the woofers should be connected in parallel. Will this work? I want to know your opinion. have a good day.

    Commenter image

    Buck Pomerantz from Crutchfield

    on 1/20/2022

    Moon, If you have two DVC 2-ohm subs rated for 150 watts RMS each, they can be wired safely to that amp like this. In the diagram, the voice coils of each sub are wired in series, while the two subs themselves are wired together in parallel.
  • Austin from Homestead

    Posted on 12/31/2021

    So I have 4 SVR-8 | 8" 800 WATT woofers and wanting to know if my amp will power them. It's a older kenwood kac-8103d 1000w mono block class d amplifier. Or if you could tell me what amp will work best for this setup

    Commenter image

    Buck Pomerantz from Crutchfield

    on 1/3/2022

    Austin, That amplifier can power one or two of those subs successfully, but not four. Four DVC 2-ohm subs will work best with an amplifier that can send them up to 1600 watts RMS at 1- or 4-ohms, like a JL Audio HD1200/1.
  • Victor from Suwanee

    Posted on 12/23/2021

    Hello, I have a 2012 Nissan Frontier on 300 watts alpine Amp with 2 10s what do I need to do to get better bass coming out those 2 10s? Maybe higher amp around 809 watts?

    Commenter image

    Buck Pomerantz from Crutchfield

    on 12/27/2021

    Victor, Check out Tuning your subs for some help improving the sound of your bass.
  • Ron from Longview

    Posted on 12/23/2021

    Hello.. Can a kicker 1800.1 push 4 Skar 15"s with a 1200 watt max with a 600 watt rms or should I get a bigger Amp (Watt)

    Commenter image

    Buck Pomerantz from Crutchfield

    on 12/23/2021

    Ron, Without knowing precisely which subs 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.
  • David Hovorak from North Zulch, Texas

    Posted on 12/15/2021

    With Dual Voice Coil Subwoofer, and two channel amplifier. Can each Voice Coil be connected to a separate channel on the amplifier? Hence, one Voice coil connected to left channel, and the other Voice coil connected to the right channel?

    Commenter image

    Buck Pomerantz from Crutchfield

    on 12/15/2021

    David, You can do that as long as each coil can handle the amount of power the amp's giving it, and each amp channel can handle the impedance of each coil, and the signals of the two channels are identical so no interference distortion is created.
  • Bomba h from Tucson az

    Posted on 12/12/2021

    Will a 3500 watt rms amp hook up to two 750 w rms type Rs which exceeds wattage for those subs will it play longer with out overheating because of greater wattage?

    Commenter image

    Buck Pomerantz from Crutchfield

    on 12/13/2021

    Bomba, Sending 3500 watts to a 1500-watt rated sub system will probably burn the coils, blow-out the surrounds and suspensions, and generally destroy the individual component subwoofers. You should not send a sub more power than what it's rated for.
  • William Scott Thomas from Syracuse

    Posted on 12/6/2021

    I have a kicker 1800.1 amp and I'm interested in buying two 12" Alpine SWX-1234D Subs. I was told that they were upgraded to handle 1500watts from its original 1000watts rms. Would my amp be a good fit?

    Commenter image

    Buck Pomerantz from Crutchfield

    on 12/6/2021

    William, Whether you have a Kicker CX1800.1 wired at 1-ohm or a CXA1800.1 wired at 4-ohms, the amp will work with those subs.
  • Eric from Hong Kong

    Posted on 11/25/2021

    Hello, any suggestion for amp to work with a single Focal P25F 10" sub with 300 watts rms and 4 ohm? Would the Kicker 46CXA1200.1T too much for it? Thanks.

    Commenter image

    Buck Pomerantz from Crutchfield

    on 11/29/2021

    Eric, That amp will probably blow that sub to smithereens - it's about twice as powerful as what the sub can handle. A 300 watts RMS rated SVC 4-ohm sub will work best with and amp that can give it no more than 300 watts at 4-ohms, like a Sound OrdnanceM350-1.
  • Rickey Gamble from Houston

    Posted on 11/9/2021

    What is a good amp for 4 kicker cvx 12 that will give me the best I want

    Commenter image

    Buck Pomerantz from Crutchfield

    on 11/9/2021

    Rickey, Those subs come in DVC 2-ohm and DVC 4-ohm models with both rated for 750 watts RMS. Four DVC 2-ohm subs rated for a total of 3000 watts RMS will work well with an amp like a Memphis VIV3000.1V2. Four DVC 4-ohm subs rated for a total of 3000 watts RMS will work well with an amp like a Rockford Fosgate T2500-1bdCP.
  • Chris M. from Bellmore

    Posted on 10/26/2021

    Will using an amplifier that does not have a high-enough RMS rating for the it's respective subwoofer, in my case I have a Soundstream Rubicon Nano Monoblock class-D amplifier (About 1500W RMS @1Ohm) powering my X-Series V.3 18"Inch Sundown sub(RMS rated @2000watt), damage the sub itself?; Or will this just put a lot of pressure and work towards/on the Soundstream amplifier, possibly burn it out? I say all of this, because I'm nervous I could have damaged my brand new sub (Less than 2 months old) and after I was playing the music decently loud and smelt a scent of burning and then the amp cut-off which lead to no power to my sub. I have a bigger amplifier that can handle the sub, I just haven't had the time to install it. I was planning on doing it within the next week but now I'm praying I didn't damage my sub-itself during the process.

    Commenter image

    Buck Pomerantz from Crutchfield

    on 10/27/2021

    Chris, Low power just means softer volume, there's no problem there. It does sounds like your sub amp's gain was not set correctly, allowing clipped signals to cook the sub's voice coil. Check out Tuning your subs for help with that.