OhEightGT

Hello everyone!

First off, you'll have to forgive my ignorance to this stuff. I know absolutely nothing about systems, which is probably why I cannot find the answer I am looking for as I don't even know where to begin or terms to search. I recently installed a pair of MTX 12 inch subs, Thunder TS55 with a MTX Thunder Elite 8010 amp, and a capacitor. The dash unit is a Pioneer Avic X930BT I believe (I don't have the box anymore).

Now, the subs and amp and all were given to me. The subs came in an enclosure together, and worked perfectly after I got everything wired and installed. But the trouble was, they are so massive in that enclosure that they would not fit in the trunk. I had them sitting in the back seat, just to test them out. Worked perfect, like I said. I bought individual boxes for them, and mounted them in the trunk. Nothing else has changed, at all. Now, when the car is off, the subs and everything work perfectly. When the car is running, at random times the bass will hit, and the subs will hang in a constant BOOOOOOOOM (regardless of what the music is actually doing) until I literally get out, and unplug everything. Even shutting the car off won't kill them (sometimes). Sometimes they only hang for a few seconds. Sometimes shutting the subs off at the AVIC in dash will kill them, but like I said often I have to pull over and physically unplug everything. Needless to say they just ride around in my trunk turned off right now.

What can cause this? I can listen to them as much as I want with the car off, just the key in accesory, but if the engine is running, every other bass hit they will hang in a constant boom. They worked perfectly until moving them to the trunk in seperate boxes. I could drive around as much as I wanted listening to music and they wouldn't do it. Not even once. The wiring has not changed, the amp/wiring of it and the capacitor has not changed. And they only do it when the engine is actually running. In accesory/key off, they never do it at all, they work fine. Someone suggested that the RCA cables to the Amp from the dash unit being crimped or damaged can cause that, I bought a new set, and they are not damaged or crimped in any way, shape, or form.

Sorry for the vagueness of my post and if it could be found easily in a search, like I said I know nothing about sound systems, this was just given to me.

SUPRA88

There is missing ground signal on the rca jacks when the wires are damage cut burn it makes that noise, in your case the problem is the pioneer radio
typical problem with pioneer radio, if the rca jacks touch ground or power for a second it burns a small trasistor resistor on the radio, get a piece of wire and connect it to chasis ground
next time there is a noise ground this to the rca jack on the amplifier only one jack any of them, if this helps pull the radio out and move the rca jacks to the front or woofer output
i believe Avic X930BT comes with 3 parts of jacks,
good luck

OhEightGT

Yeah, I have heard it can be the RCA jacks, but like I said I know in this case for sure that is not the situation. And it's not the Pioneer Avic either, sadly. Put a Sony in out of my wife's car to test that, and it did the same thing it was doing with the Avic, so I put my Avic back in. You're saying I need to attach a ground wire to the RCA cable itself? The RCA jacks are already plugged into the woofer output. There are three, jacks, but not three pairs of jacks.

Thanks for replying and helping me try to narrow it down!

SUPRA88

Just to test , when the noise is there ground the outside ring part of the RCA jack it can be any of them just one not all

Thundersteel

FYI...capacitors are a waste of money.

If your headlights dim, then you need to upgrade the "Big Three." The "Big Three" upgrade means improving the current capacity of three cables: 1) alternator positive to battery positive, 2) battery negative to chassis, and 3) engine ground to chassis.

This requires adding additional cables, or replacing the stock cables with heavier gauge cables.

Shaft

Capacitor is a last resort. Red Top Optima battery first, then high output alternator, 2nd battery, then capacitor.