Car Speakers Popping? How to Fix On/Off Speaker Pop in Your Car

How to troubleshoot and fix car speakers popping

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