Most questions I get are along the lines of, “How should I wire [this amp] with [these speakers]“, or “How should I wire my amp to my subwoofers for the most performance?” and so on.
Because of that, I’ve decided to put together this master guide with great diagrams to show you the best way to hook up an amp and subs for your installation.
In this guide you’ll find:
- How to wire your subwoofers based on the Ohms rating, the number of voice coils, and the number of subwoofers.
- Series vs parallel subwoofer wiring which is best? (It makes a big difference!)
- Diagrams explaining how to wire 1Ω, 2Ω, or 4Ω capable mono or stereo car amps to different subwoofers.
- Amp power output and speaker power differences for different speaker Ohm loads.
- Free diagram downloads you can save, print, and use any time you like!
- The best way to hook up and amp and subs – what to know first
- How wiring speakers in series or parallel affects power
- Single voice coil vs dual voice coil subwoofers
- How do you wire a dual voice coil? (Example and WHY)
- Can you wire a single voice coil sub to a dual voice coil?
- Why is it bad if speaker impedance is too low? NEVER be careless!
- Amp + subwoofer hook up diagrams – 1 Ohm stable amps
- Amp + subwoofer hook up diagrams – 2 Ohm stable amps
- Amp + subwoofer hook up diagrams – 4 Ohm stable amps
- How do I know what Ohms rating my car amp can handle?
The best way to hook up and amp and subs – what to know first
What you need to know to hook up and subs the best way
To hook up an amp to subwoofers the best way we have things we need to try for:
- Wiring the subwoofers in a way that’s the best available option for power and at the same or higher Ohms rating, the amp is rated for. Sometimes it doesn’t work out for the best amplifier power if you’re trying to use subwoofers that can’t be wired to the same min. Ohms rating as the amp for its maximum power output.
- Wiring the subwoofers in such a way we can deliver the most power and drive as many voice coils as we can. That’s if it makes sense in a particular setup. If we can do so, that’s great, as we can drive the subwoofers fully. Sometimes you simply can’t do it.
- For cases where the speakers are mismatched to the amp (the Ohms rating for the speakers isn’t ideal for the amp or trying to use dual voice coils won’t work out well), we’ll have to do the best we can with what we have.
Based on what I’ve seen repeatedly, the important thing to understand here is that many people try to use subwoofers that can’t be matched just right to an amp so you’ll have to live with some compromises.
That may turn out to be not using all of the voice coils available, not getting the full power possible from your amp, or not being able to use all of the subwoofers you want to.
How this article is organized
Since there are lots of different car amps out there but most fall into a few similar categories. I’ll organize the diagrams based on these things:
- The minimum Ohms rating of the amp (the Ohms it’s “stable to”).
- The speaker type (single or dual voice coil), different Ohms ratings for those speakers, and 1 to 4 subwoofers.
Those two things will allow me to help you the most, so all you’ll have to do is look up what you’re using in most cases and then wire your subs and amp according to the diagram and the recommendations in the notes provided.
How wiring speakers in series or parallel affects power
It’s important to understand that there’s no “free lunch” as the expression goes when it comes to speaker wiring, amp power, and speaker power. There’s only so much power or heat an amp can produce or handle.
It makes a big difference how you wire your speakers to your amplifier or car stereo.
Wiring multiple speakers can be confusing because if the speaker Ohms load is too low your amp will run hot and is subject to shutting itself down or even suffering permanent damage. Wire your speakers with too much total speaker resistance (impedance, in Ohms) and the amp won’t be able to put out anywhere near what it would otherwise. That also means each speaker will get a lot less power too.
The truth is that wiring speakers is often a compromise between the number of speakers you can use, available power, and the Ohms load your amp or stereo will “see.”
Series or parallel speakers which is better?
Because of how they work, you’ll get the most power from your amp and to each speaker when they’re wired in parallel. Parallel speaker wiring is generally best for audio speaker systems like in the car or home.
However, as you can see from the speaker and amp wiring diagrams at the beginning of the article it’s not always possible. You can only use a few speakers in parallel before the Ohms load at the amp will be too low and exceed the safe minimum Ohms rating it can handle (also called what Ohms load the amp is “stable to”).
Single voice coil vs dual voice coil subwoofers
Dual voice coil subwoofers can be used with one or both of their voice coils, although you won’t be able to drive with the same amount of power as you could using both voice coils. They can also have somewhat different behavior and lower heat handling depending on the design when using only one set of speaker terminals.
But why are dual voice coil subwoofers useful and how do they work?
What does dual voice coil mean?
Dual voice coils offer a second coil to drive the speaker cone, giving you more options for installation like different Ohm speaker loads as well as more power handling capability.
Dual voice coil (DVC) speakers are very similar to single voice coil (SVC) models but with a few differences and advantages:
- They add a second voice coil winding to the bobbin and the second set of wiring terminals with the same Ohms rating as the first one.
- By driving both voice coils the total power handling is higher and an amp can deliver more power at the lower total impedance (the speaker load, in Ohms). Using only one coil means the power you can deliver is limited, usually at 1/2 of the speaker’s maximum continuous power rating (RMS power usually). With DVC speakers, each coil runs cooler than using one one voice coil by itself as they share the power load & work they do.
- They can be ideal for wiring configurations where you need more Ohms flexibility, would like to drive a subwoofer with 2 amp channels instead of only one, or want a subwoofer you can drive harder.
Dual voice coil speakers behave a little bit differently than single ones. While their technical speaker specs are mostly the same, you’ll measure a bit less sound pressure level (SPL) and temperature handling using when using one voice coil versus two.
Some vehicles with a factory premium audio system use a dual voice coil woofer, for example, to create more bass from very limited space.
Because wiring can be confusing to a lot of people (and because you end up wasting amp power or even worse – damaging your amp!), I’ve put together some clear diagrams for recommended amp and speaker wiring hook up to help you.
Do I have to use both voice coils on subwoofers?
No, in most cases using one voice coil is fine although you’ll get the most performance by using both. Unfortunately using both voice coils often isn’t going to be easy if you’re using speakers you’ve already bought without carefully thinking about whether or not then can all be use for a particular amp.
Using a DVC subwoofer with both coils being powered means:
- More total power can be handled by the speaker and it’ll run cooler than a single one when given more power.
- Better sound pressure level (SPL) performance.
How do you wire a dual voice coil? (Example and WHY)
While they’re really similar to standard speakers, dual voice coil speakers have some considerations when hooking them up:
- Parallel voice coil connections: always connect the terminals using the same polarity on both sides. For example, if you connect your amp’s positive wire to the positive terminal on one set of voice coil terminals be sure to do the same for the 2nd set.
- Series voice coil connections: Similarly, (1) connect the first set’s positive terminal (+) to the positive speaker wire. From there, connect that set’s negative terminal (-) to the positive terminal of the 2nd set. Run the amp’s negative wire to the negative wire of the second set.
In both cases, with dual voice coil speakers, it’s extremely important to use the same speaker wire polarity. That’s because the magnetic field polarity – and which direction the voice coils will try to move the speaker – are directly related. If the polarities aren’t correct the magnetic fields and movement will be canceled, leading to extremely poor function and even potential damage!
Always be consistent when connecting DVC speakers and be careful to check your connections before dumping a lot of power to the speakers immediately. Instead, it’s better to start with a low volume and make sure everything’s working right when completing a new installation.
Can you wire a single voice coil sub to a dual voice coil?
The great news is yes, you can wire a single voice coil speaker to a dual voice coil speaker. In fact this will come in very handy in some of my diagrams below as it makes it possible to use multiple speakers with an amp.
How to wire a single voice coil sub with a dual voice coil sub
It’s pretty easy, actually, but as with other things related to DVC speakers, it’s important to be sure your speaker polarity is correct. To wire single and dual voice coil subs together:
- Parallel-series connection: Wire the positive DVC speaker terminals to the amp’s speaker wire. Wire the DVC negative terminals together, then to the positive speaker terminal of the single voice coil speaker.
- Series-series connection: Connect the first positive terminal of the DVC speaker to the amp’s positive wire. Connect the negative terminal to the 2nd set’s positive terminal. Next, connect the 2nd set’s negative terminal to the positive connection of the SVC speaker, then out from its negative terminal to the amp’s negative speaker wire.
- (Standard) series connection: Connect the positive terminal of one of the DVC speaker’s terminals to the positive speaker wire then the negative terminal to the SVC speaker’s positive wire terminal. From its negative terminal connect to the amp’s negative wire.
Observing polarity ensures you don’t have an issue with the DVC speaker’s voice coils fighting against each other (and possibly causing damage) or causing sound cancellation by working against other speakers.
Why is it bad if speaker impedance is too low? NEVER be careless!
Just like any other device connected to an electrical power source, the speaker impedance will directly affect how much or how little electrical current an amplifier will try to put out in order to supply those power-hungry speakers. (Speaker impedance also affects how some speaker components such as speaker crossovers behave too but that’s a separate topic you can learn about here).
What happens if speaker impedance is too low?
You can connect a higher speaker impedance in most cases without any real problems to worry about. A radio, home or car amplifier, etc will still produce sound and run at normal or low temperatures. That’s because a speaker with a higher impedance than expected will reduce how much electrical current the audio source tries to produce.
As a side effect, you’ll get sound but with a much lower power output than you would with the correct speaker load. Car stereos or amps, for example, have to work with lower voltages than home stereos so they need a lower impedance such as 4 ohms or 2 ohms to produce lots of power.
Home stereos, on the other hand, have higher voltage available and can use a higher speaker impedance (8 ohms, typically).
An internal view of an amp is shown here. When connected to a speaker impedance load that’s too low, the amp will begin to get very hot and this can burn out the output transistors as they can’t handle the heat stress.
However, using a lower speaker impedance is bad because it causes the amp to try and put out twice as much (or more!) current than it’s designed for. When that happens will get very hot quickly and if you’re lucky will go into a self-protect mode and shut itself off.
What usually happens when you use a lower Ohms rating
In my experience, it’s common for the output stage electronics to burn out when connected to a lower speaker load than they should be. The high-power transistors in an amplifier re only rated for a certain amount of heat & electrical current.
When they’re forced to try and handle an amount outside that range they become super hot and start to break down permanently. It doesn’t take long before the damage is permanent and they no longer produce sound.
Amp + subwoofer hook up diagrams – 1 Ohm stable amps
These diagrams show how to wire a 1Ω stable car amp with 1 to 4 speakers. To keep things neat I’ve divided it up into four sections based on the subwoofer Ohms rating and the number of voice coils:
- Diagram #1: 2Ω SVC subwoofers with a 1 Ohm stable amp
- Diagram #2: 4Ω SVC subwoofers with a 1 Ohm stable amp
- Diagram #3: 2Ω DVC subwoofers with a 1 Ohm stable amp
- Diagram #3: 4Ω DVC subwoofers with a 1 Ohm stable amp
Each one has a download button handy at the bottom.
Diagram #1: 1 Ohm stable amp + 2Ω single voice coil subwoofer wiring
Diagram #2: 1 Ohm stable amp + 4Ω single voice coil subwoofer wiring
Diagram #3: 1 Ohm stable amp + 2Ω dual voice coil subwoofer wiring
Diagram #4: 1 Ohm stable amp + 4Ω dual voice coil subwoofer wiring
Amp + subwoofer hook up diagrams – 2 Ohm stable amps
These diagrams show how to wire a 2Ω stable car amp with 1 to 4 speakers. To keep things neat I’ve divided it up into four sections based on the subwoofer Ohms rating and the number of voice coils:
- Diagram #1: 2Ω SVC subwoofers with a 2 Ohm stable amp
- Diagram #2: 4Ω SVC subwoofers with a 2 Ohm stable amp
- Diagram #3: 2Ω DVC subwoofers with a 2 Ohm stable amp
- Diagram #3: 4Ω DVC subwoofers with a 2 Ohm stable amp
Each one has a download button handy at the bottom.
Diagram #1: 2 Ohm stable amp + 2Ω single voice coil subwoofer wiring
Diagram #2: 2 Ohm stable amp + 4Ω single voice coil subwoofer wiring
Diagram #3: 2 Ohm stable amp + 2Ω dual voice coil subwoofer wiring
Diagram #4: 2 Ohm stable amp + 4Ω dual voice coil subwoofer wiring
Amp + subwoofer hook up diagrams – 4 Ohm stable amps
These diagrams show how to wire a 4Ω stable car amp with 1 to 4 speakers. To keep things neat I’ve divided it up into four sections based on the subwoofer Ohms rating and the number of voice coils:
- Diagram #1: 2Ω SVC subwoofers with a 4 Ohm stable amp
- Diagram #2: 4Ω SVC subwoofers with a 4 Ohm stable amp
- Diagram #3: 2Ω DVC subwoofers with a 4 Ohm stable amp
- Diagram #3: 4Ω DVC subwoofers with a 4 Ohm stable amp
Each one has a download button handy at the bottom.
Diagram #1: 4 Ohm stable amp + 2Ω single voice coil subwoofer wiring
Diagram #2: 4 Ohm stable amp + 4Ω single voice coil subwoofer wiring
Diagram #3: 4 Ohm stable amp + 2Ω dual voice coil subwoofer wiring
Diagram #4: 4 Ohm stable amp + 4Ω dual voice coil subwoofer wiring
How do I know what Ohms rating my car amp can handle?
One thing is ALWAYS true: the best way to find out the minimum Ohms rating for your car amplifier is by checking the specifications! Unfortunately, in my experience a lot of people don’t bother and then can’t figure out how to correctly wire their subwoofers to their amp.
The amp’s specifications are usually listed on the box, in the owner’s manual, the manufacturer’s website, or the product info from the retailer.
Car amplifier Ohms rating specification example
Example specs showing the speaker Ohms rating for a typical car amplifier. The Ohms speaker load specification lists the minimum Ohms load an amp is stable to (that it can handle safely) along with the channel configuration and continuous power it can provide.
Car amplifiers nearly always use the same specifications listings. The minimum speaker Ohms load it can support, in “modes” (speaker channel configurations). These are usually shown as “x1” for a mono amp or a bridged pair of channels, “x2” means using two channels where the ratings are per channel.
Similarly, you’ll see “x4” for four-channel amps and so on for others. When you see a specification that includes voltage (such as “14.4V” like shown above), that means the power output is what’s available at that vehicle’s electrical voltage. That’s because cars and trucks fluctuate in the battery & electrical system’s voltage as it charges, once it’s reached a charged state, and also when the motor is turned off.
A lower voltage means the amp will be able to supply somewhat less power due to having a lower input source.
Common car amplifier speaker Ohms ratings
While you should always check to be 100% sure, there are some pretty common speaker impedance (Ohms) ratings for most car amps:
- 2 or 4-channel amps: many today have a 2Ω min. Ohms rating in stereo (2 ch.) mode and a 4Ω min speaker load when bridged.
- 5 channel car amps: Like 4 channel amps, 5 channel amps are usually also 2Ω/4Ω (stereo/bridged mode) rated while the 5th (subwoofer) channel can be 2Ω or 4Ω in some cases.
- Mono amps: mono amps are a case of “it depends”; there are 4Ω stable, 2Ω stable, 1Ω stable, and even 1/2Ω stable amps although 1/2Ω is a bit rare. 1Ω is more available now than it used to be.
It’s also very important to know so that you’re careful about never connecting a speaker load to your amp in such a way that it causes it to run hot and even suffer permanent damage. I’ll cover this in a section below in more detail.