Aftermarket Audio System Broke My Car?

[WI_Mirage]

I installed a new a audio system in my Mirage a few months ago.

• Kenwood eXcelon KDC-X702 Receiver
• JL Audio M500/3 Amp
• Two Hertz DSK 165.3 150W Component Speakers
• JL Audio CS112TG-TW3 12in 400W Subwoofer

I'm a cheap *******, but I LOVE LOUD MUSIC. I wanted to hurt my ears and feel that bass in my chest. I did not want to cheap out on this hardware.

I watched lots of videos, read lots of forums and articles, and went to town on my Mirage. I installed everything properly. Except I didn't do one very important thing... The Big 3 Wiring Upgrade.

My entire system was working 100% fine for a couple weeks after the initial install. I am now dealing with a feedback issue that is causing my speakers to "whine".

One day, while I was cranking my system to its 100% capacity, I hear a loud POP. At first I thought this was a car's exhaust driving by. Now, I know I will get poop for this, but because it was a few months ago, I cannot be 100% sure when I say that this "whine" problem started immediately after I heard this POP sound. What I can say, is that the "whine" did start after the POP sound. I will also say that pre-POP I was smelling something like a burning or melting? I KNOW, THIS IS DUMB OF ME, I IGNORED IT. Additionally, post-POP the smell started to go away (it is completely gone now).

I had a lot going on, winter was approaching, and I just had to put this project on the back burner. My memory is not the greatest. Sorry I cannot be more specific.

I spent this weekend troubleshooting my car. Trust me, I did everything possible. I narrowed my problem down to this:

1. With the RCA cables unplugged from the amp, and everything else still connected to the amp (power, ground, remote, 2 speakers, 1 sub), there is a very slight "whine" noise
2. With the RCA cables and the recevier plugged in, the "whine" noise is much much louder

Yes, I have checked the radio fuse at the interior fuse box; it is fine.

Tomorrow I will bring in my car to the audio shop to have both my receiver and amp tested. This will rule out either of those being faulty (or, maybe one of them is faulty). If neither of those are faulty, then that POP noise came from my car.

I will be doing the big 3 upgrade, as mentioned above. However, if the amp is OK, and the receiver is OK, and the stereo fuse is OK, then what the hecking heck made that POP noise? Because like I said, the entire system was working 100% fine for a couple weeks before POP. Even if my amp is fine, receiver is fine, and I do the big 3 upgrade, the whine will still be there until I figure out what happened. Does anyone have any ideas?

[BecauseRaceCar]

Where did you ground the amplifier? Also, what is your audio source, bluetooth or a flash drive? I know when I useb a bluetooth dongle connected to my aux port on the base stereo that I would get noise if I used my accessory outlet to charge it. I would definitely start with tracing your grounds and ensuring that there is a clean power source to the radio and audio input.

[WI_Mirage]

Where did you ground the amplifier?

Underneath the passenger side seat belt, on the piece of vertical metal that runs the entire length of the car. I used a sanding bit on a drill to get it down to bare metal. Then I used self-tapping screws and wire teeth washers to secure the eye terminal. The ground cable is 4 AWG, about 16 inches long.

Also, what is your audio source, bluetooth or a flash drive?

I've tried radio, aux, CD, bluetooth, and USB. All have the same issue.

I would definitely start with tracing your grounds and ensuring that there is a clean power source to the radio and audio input.

The power source running to the amp is a 4 AWG wire which connects directly the battery in the engine compartment.


Also, the ground for the receiver is a spade terminal attached to a bolt going strait into the metal bars behind the dashboard.

[BecauseRaceCar]

I have no complaints about your grounds. It sounds like they are solid. After looking through the manual for the receiver my only other thoughts are possibly the gain settings for the High pass Filters or maybe the pop was the amplified sound of a filtering capacitor internal to the radio failing. if your harness is still complete I would suggest trying the factory stereo again to rule out any issues with the car's electronics.

[WI_Mirage]

After looking through the manual for the receiver my only other thoughts are possibly the gain settings for the High pass Filters or maybe the pop was the amplified sound of a filtering capacitor internal to the radio failing.

I turned off the EQ on the receiver. Is this what you mean by high pass filters?

If your harness is still complete I would suggest trying the factory stereo again to rule out any issues with the car's electronics.

I do not have the factory stereo. I actually installed this Kenwood receiver about two years ago when I got the car. The factory stereo was pretty beaten up. The display was half broken. When I put a new battery in the car, the stereo turned off completely. The On/Off button wasn't working so it wouldn't even turn on after that. But, when I'm at the audio shop tomorrow I will ask if they have a spare Kenwood with the same harness port as mine that I could use to test this.

[BecauseRaceCar]

I was looking at page 30 of the PDF manual from Kenwood's website under the "X'over" heading. it refernces levels from -8 to 0. After seeing the pictures of your sound deadening install and the grounding method you chose I can only think that it is either a fault in the radio or possibly a minor setting in the radio or on the amplifier.

[WI_Mirage]

After seeing the pictures of your sound deadening install and the grounding method you chose I can only think that it is either a fault in the radio or possibly a minor setting in the radio or on the amplifier.

I believe those pictures have the prior ground I was using, which was the hump running under seat that holds the bolts for the two front seat mounting points. I moved the ground here just to be 100% sure it had a better flow. This is under the passenger seat. I just snapped a couple pics:




I just noticed all the grime under the seat I spilled a soda on that seat and never cleaned it.... there's another project for me haha.

[WI_Mirage]

I was looking at page 30 of the PDF manual from Kenwood's website under the "X'over" heading. it refernces levels from -8 to 0. After seeing the pictures of your sound deadening install and the grounding method you chose I can only think that it is either a fault in the radio or possibly a minor setting in the radio or on the amplifier.

I see the X'over settings now. I will mess with those tomorrow and see if I can produce a good result out of it. However I doubt this is the issue, because for the two weeks the system was working all the receiver settings have remained the same since.

[BillAce]

How many RCA preouts are you using from the Kenwood head unit? Can you try a different output? My guess is the preamp in the amplifier was damaged by overdriving it. The smell was likely caused by excess heat from clipping.
I woud normally power the amp from a power supply outside the car to rule out the electrical system then check the head unit preout by running an RCA to another system(amp) then swap the amp if the source of the issue wasn't found. Good luck

[WI_Mirage]

How many RCA preouts are you using from the Kenwood head unit? Can you try a different output? My guess is the preamp in the amplifier was damaged by overdriving it. The smell was likely caused by excess heat from clipping.
I woud normally power the amp from a power supply outside the car to rule out the electrical system then check the head unit preout by running an RCA to another system(amp) then swap the amp if the source of the issue wasn't found. Good luck

I'm using 2 RCA preout pairs, one for the front speakers and one for the sub. I can try plugging the front speakers in the RCA rear speaker preout.