If your car speakers are popping, it can be due to several different reasons. Below, I’ll break these down into speaker pop and amp pop. As well as turn on pop and turn off pop.

What is turn on / turn off pop?

You may have noticed that after installing a new piece of equipment, you will get a pop in your speakers or subwoofer when you first turn the key on, turn the key off, or sometimes both. There can be many causes of turn on/off pop including amp ground, bad amp, or the order the amp is being turned on or off.

Turn On Pop

Usually what is happening is the amp will turn on first, then your radio or whatever source you have feeding the amp is turning on which will cause an inrush current to the already turned on amp which causes the speakers to pop. The problem can also be with the amp itself. How to troubleshoot and fix both of these issues is described below.

Turn Off Pop

Turn off pop is the opposite; the radio is turning off before the amp which sends a signal to the amp that gets amplified as the amp is powering off. This can also be an issue with the amp itself and methods to troubleshoot and fix these problems are found below.

Jump to section:

• How to troubleshoot turn on/off pop
• PAC TR-4 vs TR-7 vs Stinger SGN21 vs Metra Axxess AX-MTR
• How to fix stereo turn on pop
• How to fix amplifier turn on pop
• How to fix stereo turn off pop
• How to fix amplifier turn off pop
• How to fix AudioControl pop

How to troubleshoot car speakers popping

First thing to do is unplug the RCAs from the amp and turn the vehicle on or off depending on when you hear the pop. If the pop is still there, check your grounds. If the pop is gone, go to the next step. If that doesn’t help, it’s likely there’s a problem with the amp or radio itself. One way to fix this is to wire relays  into the speaker wires themselves to disconnect the speakers from the amp at turn on/off in conjunction with a delay module like the PAC TR-4, TR-7, Stinger SGN21, or Metra Axxess AX-MTR. The amp will still be making the “pop” internally, but it wont send that possibly damaging signal to your speakers.

If the pop sound disappears once you disconnect the RCAs, then the problem is most likely from your amp being turned on first. Next, plug the RCAs back in and remove the remote wire from the amp. Now turn the key on and wait a couple of seconds then touch the remote wire back to the amp to turn it on. If the amp comes on with no pop, then a trigger delay device will fix your problems. If there is still a pop, it’s likely a problem with your amp, and you will have to isolate the speakers as well as use a delay module.

You can also use this same method in reverse to troubleshoot turn off pop. To determine if it’s the amplifier or the radio causing turn off pop, disconnect the remote wire from the amp while the vehicle is on with music playing. If it still pops, you have amplifier off pop. If it does not pop, it is likely the radio itself or whatever source you used for remote turn on signal. This can be fixed under the stereo off pop section below.

Most aftermarket radios have a built in delay on the remote turn on wire, so turn on pop is usually not as much of a concern. There are some cases where the delay isn’t long enough, though, and an external delay may need to be used.

Recommended Installation Tools and Accessories:

• Digital Multimeter
• Crimpers
• Butt Connectors
• Zip Ties
• Electrical Tape or Tesa Tape

TR-4 vs TR-7 vs SGN21 vs Metra Axxess AX-MTR

PAC TR-4    (click here for product page)

Buy the TR-4 on Amazon

This is the simplest and least expensive device. It has 2 main funcitons

• Eliminates turn on pop via a 1 second delay
• Add remote turn on from any voltage source over +0.8V. This means you can tap into a speaker wire to trigger your remote turn on. This especially comes in handy when adding an amp to a factory system

PAC TR-7    (click here for product page)

Buy the TR-7 on Amazon (May be discontinued)

This and the AX-MTR are the most complex devices out of the group and the most difficult to setup as they require programming depending on what you want to use it for. The TR-7’s default is Alpine video bypass, so no programming is needed for that feature. As far as this post is concerned, it can delay both amp turn on and turn off to fix either turn on or turn off pop. It has many different functions including

• Turn on pop delay
• Delayed amp turn off
• Low voltage trigger
• Alpine video bypass
• Any other radio video bypass
• Latching outputs
• Double pulse output
• Pulse extender
• Linear actuator controller
• Door lock pulse generator
• Channel splitter
• 3 in 1 timer outputs
• Pulses to timed output

Stinger SGN21 (discontinued)  

Looks like the SGN21 has been discontinued, but if you have one or are able to find one, I’ll include it in this post.

This device is between the TR-4 and TR-7 as far as features go. There is no programming like the TR-7, so this one will be a quicker install. The product page on their website mentions converting speaker wires to RCAs (an LOC pretty much). I don’t see any thing about that in the instruction manual or pictures, so it must be a typo. I have never used this product, so I’m not sure on this.

• Eliminates amplifier on pop
• Eliminates amplifier off pop
• Eliminates stereo off pop

Metra Axxess AX-MTR    (click here for product page)

This is Metra’s version of the PAC TR-7, so I won’t be going over this one in this post either since I don’t think it is worth the programming time just to delay the amp turn on/off. It basically has all the same features as the TR-7.

How to fix stereo turn on pop

This method is used if troubleshooting proved the pop problem is being caused due to the speaker(s) popping .If all you have is turn on pop, then the PAC TR-4 will be the easiest and least expensive module for you, although the TR-7, SGN21, or AX-MTR will still work as mentioned above. It still may be a better idea to go with one of the others just so you have something with more features in the future should you ever remove your system and don’t have turn on pop anymore.

How to wire up TR-4 for stereo turn on pop

The PAC TR-4 comes with very clear instructions, but here’s a quick overview. You can also download the instructions on the product page here.

• Yellow wire: constant +12V source
  • You can run this straight to the battery, to the radio constant wire if you will be taking the radio out, or if you don’t have to remove the radio, I like to tie this into the main power wire at the amp. It’s always best to add a fuse to this wire just to be safe
• Black wire: ground
  • Again, you can tie this in with the radio ground, amp ground, or put a ring terminal on the wire and screw it into bare metal
• Green wire: + trigger input
  • This can be any voltage source +0.8V or higher that comes on when you turn they key. Tap an accessory power fuse in the fuse box or even tie into a speaker wire (one that isn’t an output of the amp you’re connecting of course)
• Blue wire: +12V output (delayed accessory on)
  • This is the wire you will now run for the remote turn on to the amplifier. It takes whatever trigger you gave it and turns it into 12V that the amp needs to turn on with a one second delay to eliminate the pop

How to wire up SGN21 for stereo turn on pop

The SGN21 is almost identical as far as wiring goes but with different colors, and I don’t believe you can use speakers as a trigger source for it.

• Yellow wire: constant +12V source
  • You can run this straight to the battery, to the radio constant wire if you will be taking the radio out, or if you don’t have to remove the radio, I like to tie this into the main power wire at the amp. It’s always best to add a fuse to this wire just to be safe
• Black wire: ground
  • Again, you can tie this in with the radio ground, amp ground, or put a ring terminal on the wire and screw it into bare metal
• Blue wire: + trigger input
  • This can be any +12V voltage source that turns on when you turn the key. Tap an accessory power fuse in the fuse box or radio accessory wire if hooking up to a factory radio, or wire into remote turn on wire of aftermarket radio
• White/blue wire: +12V output (delayed accessory on)
  • This is the wire you will now run for the remote turn on to the amplifier. It takes whatever trigger you gave it and delays the amp turn on to eliminate pop

The TR-7 and AX-MTR can also use speaker wire as a trigger source like the TR-4, but I’m not sure if it can do a delay and this at the same time. I won’t be going over it as the instructions are confusing and it’s too much work in my opinion for something like this.

How to fix amplifier turn on pop

This method is used if troubleshooting proved the pop problem is being caused by the amp itself. Any of these modules can also be used if the amp itself is causing turn on pop. This method is the most difficult and is not listed in the instructions for the modules. It requires a relay for each speaker that is popping when the amp turns on as well as a delay module. Use both diagrams below as a guide but a few changes are necessary. The red and white/red wires in the second diagram will not be used.

What this does is disconnects the speakers from the amp when the vehicle is off, and when the key is turned on, it triggers the delay module which is used to trip the relay(s) to reconnect the speaker(s) after the amp has already been turned on.

• Yellow wire: constant +12V source
  • You can run this straight to the battery, to the radio constant wire if you will be taking the radio out, or if you don’t have to remove the radio, I like to tie this into the main power wire at the amp. It’s always best to add a fuse to this wire just to be safe
• Black wire: ground
  • Again, you can tie this in with the radio ground, amp ground, or put a ring terminal on the wire and screw it into bare metal
• Blue wire (SGN21) or green wire (TR-4): + trigger input
  • This can be any +12V voltage source that turns on when you turn the key. Tap an accessory power fuse in the fuse box or radio accessory wire if hooking up to a factory radio, or wire into remote turn on wire of aftermarket radio. In this method, you are also going to run another wire from this same source directly to the amp. This ensures the amp comes on with no delay so that you have time to delay the speakers
• White/blue wire (SGN21) or blue wire (TR-4): +12V output (delayed accessory on)
  • This wire will be run to pin 86 of the relay shown in the second diagram. This causes the relay to trip with a delay after the amp is turned on so the speakers will connect back after a short delay and the pop will not be heard
• Relay
  • You need to wire up a SPDT relay as shown above for each speaker except the accessory wire hooked to pin 86 in the diagram will be replaced with the white/blue wire of the SGN21 or the blue wire of the TR-4

How to fix stereo turn off pop

Either the SGN21, TR-7, or AX-MTR can be used for turn off pop. The TR-4 does not provide a turn off delay. I will not go over the TR-7 or AX-MTR here since the SGN21 is much easier to install.

How to wire up SGN21 for stereo turn off pop

This method is used if troubleshooting proved the pop problem is with the radio itself. Wiring the SGN21 for stereo turn off pop is similar to wiring for turn on pop, but you just use different wire colors and also wire into the radio accessory power wire.

Note: use caution when using this method on factory radios. It will also not work on all factory radios such as CAN bus turn on systems. I also would not recommend using this method to keep a fuse or other accessory wire that you may have tapped for remote turn on to stay on after the vehicle is shut off.

• Yellow wire: constant +12V source
  • You can run this straight to the battery, to the radio constant wire if you will be taking the radio out, or if you don’t have to remove the radio, I like to tie this into the main power wire at the amp. It’s always best to add a fuse to this wire just to be safe
• Black wire: ground
  • Again, you can tie this in with the radio ground, amp ground, or put a ring terminal on the wire and screw it into bare metal
• Red wire: + trigger input
  • This can be any +12V voltage source that turns on when you turn the key. Tap an accessory power fuse in the fuse box or radio accessory wire if hooking up to a factory radio, or wire into remote turn on wire of aftermarket radio. This wire will run from the ignition source to both the red wire on the SGN21 and the remote turn on input on the amp.
• White/red wire: +12V output (delayed accessory off)
  • This wire connects to the +12V accessory power wire on your radio. This is usually the red wire on aftermarket radio harnesses. This will keep the radio on after the amp shuts off to eliminate the pop from the radio

How to fix amplifier turn off pop

How to wire up SGN21 for amplifier turn off pop

Wiring the SGN21 for amplifier turn off pop is a bit more difficult than the other methods as you will need a relay for each speaker that is popping when the amp turns off. What this does is disconnects the speakers from the amp when the key is turned off, and the delay module keeps the amp on for a second so that the speakers are disconnected from the amp when the amp is shut down.

• Yellow wire: constant +12V source
  • You can run this straight to the battery, to the radio constant wire if you will be taking the radio out, or if you don’t have to remove the radio, I like to tie this into the main power wire at the amp. It’s always best to add a fuse to this wire just to be safe
• Black wire: ground
  • Again, you can tie this in with the radio ground, amp ground, or put a ring terminal on the wire and screw it into bare metal
• Red wire: + trigger input
  • This can be any +12V voltage source that turns on when you turn the key. Tap an accessory power fuse in the fuse box or radio accessory wire if hooking up to a factory radio, or wire into remote turn on wire of aftermarket radio.
• White/red wire: +12V output (delayed accessory off)
  • This wire connects to the remote turn on input on the amplifier. This will keep the amp on for a second once the key is turned off so that the relay can disconnect the speaker(s) before the amp turns off
• Relay
  • You will need to wire up a SPDT relay as shown in the diagram above for each speaker that pops

AudioControl Pop

If you have an AudioControl unit in your system and have determined this is what is causing your turn on/off pop, then AudioControl recommends moving the Ground Isolation Selector. This may also help with other noises such as alternator whine. Their units ship with this in the fully isolated position, “which we know is best” (black jumper in center position). They recommend playing with the different settings to see if it helps you. Move the black jumper to the top position for the 200Ω setting or to the bottom position for the ground setting.

If neither of these settings help, they also provide an Input Ground Isolation Selector on some units you can play with to try and fix your noise. Make sure you turn off the system before making any of these changes.

Check out AudioControl’s products on Amazon

There are many different ways to get cheap lightweight sound in your car. Of course the easiest and lightest is just listening to music on your phone from its speaker or a set of earbuds, but phone speakers suck and earbuds aren’t safe while driving. So here I will cover a few different options you have to get some decent sound in your track car.

First thing’s first. Get rid of your radio and any other sound related stuff like any amplifiers, subwoofers, etc. This is still a race car.

Speakers

Coax speakers are going to be lighter than components in this case, so I would recommend sticking with those. If you don’t know the difference, check out my Basics to Upgrading Your System post.

Factory Speakers

One option for speakers, and often one of the lightest depending on your vehicle, is just keeping the stock speakers installed. Many factory speakers use tiny magnets and have plastic baskets and paper cones. Speakers made like this are usually the lightest but won’t sound too great. But who cares? It’s a race car!

Some factory speakers (cough cough Chevy) are terribly and barely handle radio power, so hooking an amp to them will probably blow them pretty quick. Get prepared to upgrade at some point if you go this route.

Upgraded Speakers

If you want better sound quality than stock speakers even though it’s a track car, find a decent set of coax speakers like these 6.5″ Polk db651 (check price on Amazon). They are some of the best sounding coaxial speakers I have heard for the price. Amazon has the weight listed as 5 pounds. I’m guessing this is shipping weight, so just the speakers should be even less. Or you can get the shallow mount version and save a few dollars and half a pound: Polk db651s slim mount (check price on Amazon).

Some of the lightest 6.5″ speakers I found were these Infinity Reference 6032si shallow mount 6.5″ coax speakers (check price on Amazon). Amazon has them listed at 1 pound. I’m guessing that’s not the total shipping weight like the Polks.

To save even more weight, go with a smaller speaker like a 5.25″.

Most of the weight of a speaker will come from the magnet, so the smaller the magnet, the lighter the speaker generally. But this usually means a less powerful speaker unless you find with a neodymium magnet like the Lanzar VX60S VX (check price on Amazon). Speakers aren’t going to add much weight, though. Maybe 5 pounds at the absolute most.  

Amplifier

This is where most of the weight savings will come in. I don’t recommend you use a big traditional style amplifier like the JL Audio JX360/2. Many companies are starting to make very small, lightweight amplifiers. Check out the mini amp section of Sonic Electronix. As you can see there are many different amps to fit any budget.

My Recommendations

Alpine Power Pack: There are many other amps similar to this one, but this is the only one I have experience with and have nothing but great things to say about it. Great size. Great sound. Great power output. It’s even bridgeable which means instead of using 2 of its single channels to get 45W, you can bridge it to 2 channels and get 90W per channel. It’s also very lightweight. Amazon has it listed at just 2.4 pounds. But that’s not it; this amp is very easy to unplug and take out of the car. So you could very easily just mount it with velcro or something similar, and when you get to the track disconnect it and take it out to save even more weight.

Make sure you get the Alpine KTP-445U model and NOT the Alpine KTP-445A as the “U” stands for Universal and the “A” stands for Alpine. The “A” model is meant to be plug-and-play to an Alpine head unit and won’t come with RCA inputs which is important as you will see later.

This amp has individual left and right channel gain settings as well as a selectable high pass filter.

Lepai LP-2020A+: This little amp isn’t necessarily made for car audio, but it will definitely work and is very light. I have one of these powering a set of speakers in my apartment and it’s a good little amp. Using it in a car, I would make sure it was mounted securely and you will be fine. It’s not quite as powerful as many of the other choices out there at only 20W per channel, but it was also only $20 on Amazon at the time of writing this (click here to check most recent price).

Just make sure to get the right center positive pigtail to wire it into a car like this one, or you might be able to get away with cutting of the AC power supply and using the other end as a pigtail to hook up power and ground.

2021 Update:
Now that bluetooth amps are so cheap and small, they are definitely worth a look for this purpose. This will use the bluetooth on your phone as the source, and all you need to do is hook the amp up like normal minus the RCA inputs and hide it away somewhere. This Herdio marine bluetooth amp also comes with an external controller, so you can keep your phone in pocket.

Connections

Now that you’ve picked out your speakers and amp, you will need to get it all hooked up. You can follow my How to Install and Tune an Amp – With Wiring Diagram post if you need help wiring up an amp.

If you chose one of these smaller amps that don’t draw much current, you can just hook up power and ground at the radio connections (though you may need to run a separate constant power wire to the battery if your amp draws more current than what the radio fuse is rated for your car). You can either cut the wires off the harness or use an aftermarket radio wiring harness to make it easier, and you won’t have to cut into the factory harness. To find what harness your car needs, go to metraonline.com and search for your vehicle. You will be looking for a female plug similar to this:

Now that you have the amp wired up, you are probably wondering what goes into the RCA input. Go buy a cable similar to one of these RCA to headphone jack Monster Audio Cables and plug it into the amp. Run the other end up to where you will put your phone or mp3 player.

Now you control everything with your music player and do away with a radio completely. This method of simple sound also works great in Jeeps or anything else where you don’t need a radio in your car.

An alternate method would be to buy a bluetooth adapter like this one. This might be a little advanced for a race car, but it will get rid of an extra wire that may be in your way otherwise. And this one uses regular RCA cables to connect to your amp.

Now you can do away with your radio and any other factory sound system you have and get way better and louder sound than what came in your car and still stay light enough for the track.

Update

My personal setup in my Miata is a Pioneer mechless single din head unit with bluetooth and the factory speakers. The mechless (no CD player) radio is lighter and has more features than the stock radio. The one I have is very similar to this newer MVH-X390BT (check price on Amazon) and it works great.

In my STi, I have an Alpine Power Pack with an auxiliary cable for the input with a volume control knob where the factory aux input jack was running the factory speakers. I will soon be upgrading the speakers to these Sony GS components (check price on Amazon) / (read my review on them here) and possibly adding some sort of bluetooth. Sony also has a version of a mini amp like this that I have had great success with, but it is not bridgeable like the Alpine (check price on Amazon).

Update (1/20/2019)

I no longer have the Alpine power pack in my STi. I did install the Sony GS components and love them. Check out my review (here) and installation videos of them (here). I also added a Zapco ST-4XSQ amp and Sony XAV-AX5000 head unit. I may do a review on this soon as it is by far my favorite radio out right now for the price, quality, and features offered. I am a Sony and Zapco dealer, so if you are near Baton Rouge, feel free to call or email me for pricing and availability.

Car audio amplifier installation kits, wiring kits, or amp kits, usually include all or most of the things you need to install your amp, but you don’t need the full kit if you already have most of what you need; you can go buy whatever you’re missing separately. It’s usually a lot cheaper to get a kit if starting from nothing. Also make sure the kit you buy includes what you need. For example: most kits only come with one set of RCAs. This is fine for a sub installation, but you will need another pair if you plan on doing 4 speakers on a 4 channel amp.

What do car audio amplifier kits include?

Car audio amplifier kits will include the wires, cables, fuse holders, and connectors you need to install your amp. Some include more pieces than others. This 4 gauge Scosche Vector series OFC amp kit  includes everything you need to get your system hooked up and sounding good. You can get cheaper kits, but the wires won’t be true AWG size, will most likely be copper clad aluminum (CCA), won’t carry current as well as name brand pure copper kits, and will have cheap RCAs.

It’s definitely worth the extra price to upgrade to a high quality kit like the Scosche Vector Series. When looking for a pure copper amp kit, some companies will call it 100% oxygen free copper, pure copper, or OFC. These provide the best conductivity and least resistance compared to CCA.

CCA wire can be used, too, but will be a little larger gauge and from my experience, corrodes faster. Using high quality connections and proper crimping techniques help with that, though.

Car Audio Amplifier Kits include the following:

Power Wire

The Power Wire will be the longer of the two thick wires in your kit. It runs from your battery to your amp. See the chart below or calculator (click here) to determine the power and ground wire size you need for your installation.

Ground Wire

The Ground Wire will be the shorter of the two thick wires, usually less than 3 feet.  The ground wires goes from your amp to the chassis or body of your car or back to the battery. Be sure to take the Ground Wire length into account in your wire size calculations, especially if you run the ground back to the battery with the Power Wire.

Remote Wire

The Remote Wire is the long single (primary) wire in the kit, usually blue. This wire runs from a switched 12V source, like the remote turn on wire on the back of aftermarket radios, to your amp.

Speaker Wire

Speaker Wire is the wire that is actually two wires together. Obviously this goes from your amp to your speakers, one side to positive, one side to negative. Some kits do not include speaker wire. KnuKonceptz makes a good speaker wire at a great price.

RCA Cable(s)

The RCAs are signal cables that run from the output on the back of your head unit, or low level converter (more on that later), to the input on the amp. These probably vary more than wire quality does. You don’t want to skimp on RCAs or you could possibly get engine noise or other signal quality problems. Use high quality RCAs like the Scosche Delta Series here.

Fuse Holder and Fuse

The Fuse protects your car, battery, and amp from getting fried if something goes wrong (actually it protects the wire itself, so the fuse rating in your amp kit can be compared to the fuse rating on your amp to determine if the amp kit will work for you). ALWAYS install the Fuse Holder and Fuse and as close to the battery as possible, usually no more than 18″.

Various Connectors and Terminals

Most kits will come with wire connectors and terminals so you can connect the wires where they need to go. A lot of amps don’t require special connectors, so these may not be used for your install.

How to pick what kit you need

Amp kits are sized by the power and ground wire. For example, if you buy an 8 gauge amp kit, the power and ground wire will be 8 gauge. The speaker wires are usually 12 AWG or less, and the remote wire is usually 18 AWG.

The chart below shows the basic wire size you need based on your power requirements assuming the kits you are looking at are a good brand with true AWG copper wire:

Note that you need to use the total length of your power AND ground wire for the length measurement.

How to Use the Chart and Calculate Wire Size

Just match the max amperage or fuse rating on your amp to the amperage on the chart, find out how long your wire is going to be, and you can find out what size wire you need. Use the general equations below to determine the current your amplifier will pull.

For a Class D amp (assumes 75% amp efficiency and 13.8 volts): 

\begin {aligned}
Amps={Total \> RMS \> Power \above {2pt} 0.75 \> x \> 13.8 \>VDC}
\end {aligned}

For a Class AB amp (assumes 50% amp efficiency and 13.8 volts):  

Amps={Total \> RMS \> Power \above {2pt} 0.50 \> x \> 13.8 \>VDC}

You can also find a calculator here that will tell you the minimum wire size needed for your installation.

Jump up a wire gauge size if you are ever unsure, are going with a cheap unknown amp kit, or if you go with CCA instead of OFC wire.

It’s recommended to go up two wire sizes from what the chart above shows if you use CCA in order to achieve less resistance. You can’t go wrong by getting bigger wire (smaller gauge) just don’t ever get smaller than recommended. The wire will pull more current than it’s designed for and possibly cause a fire if you use a wire that is too small. The inline fuse will blow in most cases, and if that happens, don’t swap it out for a bigger one! Fix the issue, and upgrade the wiring.

This post will explain how to select a subwoofer and/or a bass amp for your setup. I will cover a few different scenarios:

1. You have a sub you want to use but need to find an amp for it.
2. You have an amp you want to use but need to find a sub for it.
3. You don’t have either and are looking to get both a sub and amp.
4. You will be adding speakers and a sub and want to find a single amp to power them all.

1. You have a sub you want to use but need to find an amp for it.

If you already have a sub you want to use or want the same sub as a friend, etc. then you need to find out the specs of the sub. You can usually find these on the box or manufacturers website or a website that sells products (soon to be this one) like Sonic Electronix or Amazon.

What you are looking for in these specs is the RMS (root mean squared, or continuous) power rating, how many voice coils your sub has, and the impedance (ohms). Many subs will have a power rating listed that is max power. This is not what you are looking for when selecting an amp. Your sub and amp will spend most of its time at RMS, not peak power.

Once you find these specs, you need to find an amp with the same (or similar) RMS rating at the impedance your sub is. You can get a more or less powerful amp, but with less power your sub won’t hit as hard. And with more power, you risk overpowering your sub if you don’t tune the amp right (more on that later).

In both of these cases, you run the risk of blowing you sub. If underpowered, you will likely try to turn the gain on the amp up to get the most out of it. This sends a clipped signal to the speaker and can fry the voice coil(s). If overpowered, the speaker tries to play past its max excursion which can break or tear the voice coil, spider, or surround and ruin the sub. Here is a great article explaining this on Crutchfield.

So, it is best to find an amp with a similar RMS rating to your sub. This can be more difficult when going with cheaper brands, though, as they tend to overrate everything. It’s hard to say with these without testing, but if you go with a CEA compliant amp and sub, you know you will be close in ratings.

Here’s an example:

Say you have a 4 ohm single voice coil JL 12W3V3 sub ($240 with free shipping on Amazon) with an RMS power rating of 500 watts. Now JL also has a recommended power range for this sub of 150-500 watts RMS. This means any amp with an RMS rating between 150-500 watts at 4 ohm will work fine with this sub. But we’ll assume you want to get the most out of it, so we’ll look for a CEA compliant amp that puts out 500 watts RMS at 4 ohms.

[amazon asin=B0035VQ5BY&template=add to cart]

Would you look at that! Sonic Electronix has a whole list of CEA Compliant amps. If you are just looking to power a sub, a monoblock amp will be what you are looking for. You can also use a 2 channel amp and bridge the channels, but doing that you can usually only run a 4 ohm sub (which is fine for this situation, but if you add more subs or have a 2 ohm sub may not work – more on this later). So I’m just going to go down the list and find the first 500 watt at 4 ohm CEA compliant amp I see: the Pioneer GM-D9601 ($165 on Amazon with prime shipping).[amazon asin=B00CLFM596&template=add to cart]

Of course if you are set on a different brand or lower price or smaller amp you can sort through and find something else, but that’s it! You’ve found an amp for your sub.

Note: For a dual voice coil sub, the impedance will not be what to look for on the amp. If you have a dual 2 ohm sub, you can either run it at 1 ohm or 4 ohms. If you have a dual 4 ohm sub, you can run it at 2 or 8 ohms. When you add more than one sub, this changes, but there will be more on this later if you are confused.

2. You have an amp you want to use but need to find a sub for it.

This is going to be very similar to scenario number 1, so please read that and I’ll explain the differences here.

So this time you are going to look at the specs on your amp: RMS power at different ohm loads. In the first section you have to match the sub’s impedance with an amp, but in this section you have an amp that can probably handle different impedances. This gives you a little more selection on what sub to get.

If you have a monoblock amp, it may be stable all the way down to 1 ohm (usually 2 ohms, though). If you have a 2 channel amp you plan on bridging, it will probably only be stable down to 4 ohms, though some are stable down to 2 ohms. So find out what ohm sub you want to go with.

Here’s an example:

Assume you have a Kenwood KAC-5001PS ($112 on Amazon with Prime shipping). This amp can put out 500 watts RMS at 2 ohms or 300 watts RMS at 4 ohms. In this case a 2 ohm sub will be louder, so let’s go with that. Now check Sonic Electronic’s (or others’) list of CEA compliant subs. We’ll be looking for a 2 ohm sub rated at 500 watts RMS, or a dual 4 ohm sub rated at 500 watts RMS (see the note above).[amazon asin=B00B8B0Q9A&template=add to cart]

The first one I see on the list is the Alpine SWS-15D4 – 15″ dual 4 ohm sub ($120 on Amazon with free shipping) rated at 500 watts RMS. This can be wired to 2 ohm and get the 500 watts RMS from your amp.[amazon asin=B0081JFX8G&template=add to cart]

There you go. That’s all you need to do to find a sub for your amp.

3. You don’t have either and are looking to get both a sub and amp.

For this one you will simply combine steps 1 and 2 from above, but this can be tricky since there are endless possibilities. You may have a certain budget you are shooting for, or you may have a certain brand you definitely want or don’t want to go with. The best thing to do in this situation is listen to other people’s setups and find one that is right for you and go with a similar setup.

You could also just randomly pick something. Say there is a nice name brand sub or amp on sale, so you get it. Then just go to the section above to find out how to pick the other.

Maybe you think a certain power range sounds good, so you randomly pick 500 watts RMS. Then go find a good 500 watt sub and 500 watt amp.

Once again, there are endless possibilities here, so it is best to read the above sections to get the gist of it.

4. You will be adding speakers and a sub and want to find a single amp to power them all.

For this section, you may already have the speakers and sub you want to use, or maybe just the amp you want to use. In any case, read the above sections to learn how to match power ratings of amps and subs. Matching speakers and amps is coming soon, but is the same  thing as matching single voice coil subs with their respective amps for sake of argument.

To use one amp to power all your speakers and your sub, you can use several different setups:

• 4 channel amp
• 5 channel amp
• 6 channel amp

4 Channel Amp

For this setup, you can either run just your front speakers off the first 2 channels and bridge the rears to power your sub(s) or wire the front and rear speakers on the left together and front and rear speakers on the right together to run on channels 1 and 2 and bridge the rear to power your sub.

Either way, to power a sub and speakers with a 4 channel amp, your sub will be powered by bridging two of the channels on the amp. So in this situation, you will need to find the output ratings for the amp when 2 channels are bridged and match a sub to that or vice versa.

5 Channel Amp

A 5 channel amp will have 4 channels for speakers and a single mono channel specifically for a sub. In this case you will need to match the speaker channels to speakers with the right rating (more on that later but pretty much the same thing as matching subs with amps) and match the sub channel with a sub with the right rating. This is exactly the same as sections 1 and 2 above when matching subs to a monoblock amp. The only difference is you have 4 other channels to power speakers.

6 Channel Amp

This is the same as the 4 channel amp situation, but instead of having 2 speaker channels and 2 of them bridged to your subs, you will have 4 speaker channels and 2 of them bridged to your sub.

Well there you have it. Now you can go find the right sub or amp for your setup. If you still have questions, let me know in the comments or send me an email.