hey all, i'm having a hell of a time trouble shooting this one.

i have a 2010 a4, and i've tapped into the existing sub connection in the trunk to use as an input on my amp. the amp is only powering two subs.

the battery, stock amp, stock sub line, remote wire etc. is all in the trunk, so it's a pretty convenient set up - if it only worked properly!

the set up pounds when it's on auxiliary power. it will run full blast for however long (i've kept it going for many minutes)

however, when i turn the engine on, it will cut out after a certain amount of time (this time varies, could be 20-30 seconds, could be 5)

the lights on the rockford sub will flash as if they're still recieving a signal from the stock sub line (flash along with where the bass should be) but the subs are dead.

everything magically comes back to life as soon as i restart the car, whether or not it's on aux. or engine power.

since everything is hooked up right to the battery, i'm having a hard time pinpointing it as a problem with the alternator etc... as only the subs will kick out.

this was even happening with my old sub set up, same style, but it was a cheaper MTX JAckhammer amp and a 10" MTX sub...this time it's a better rockford amp w/ 2x12" rockford HEs (although i've hooked up my old 10" MTX to the current set up and it still cuts out...)

any ideas?! they'd be greatly appreciated!

(go easy on me, by the way...i'm no expert )

 

With a name like fckaffplz it makes me wanna do this:

But I'll be nice... If you tapped into the existing sub connections, did you tap into them before the factory amp or after? What did you use to determine what wire was what? Have you been blowing any fuses?

 

Try running the RCAs from the H/U stright to the amp imput. Sounds like it might be a Factory amp issue

 

thanks guys - the sub input im using was right at the subwoofer, so after the amp. (i just unhooked the sub woofer and ran that line to the input of the amp.)

i just don't understand why it works great on aux. but cuts out on the engine! guess i gotta start rippin up the dash...

 

what did you use for the amp turn on? seems like the amp is turning off with the engine on, try jumping the remote wire to the positive on your amp and see if the problem is still there, then you know if you need a better or different remote source.

 

thanks kygreen - although the amp is actually saying ON, it's just the subs that are cutting out. the amp is even still recieving some sort of input as the lights on the amp 'flash' with where the bass should be. it's just not outputting to the subs i guess?

 

Could be overvoltage somewhere. With the engine off, not charging the battery, the amp still operates without going into voltage protection. But when the car is running and the battery is charging, the voltage of the system is higher.

You said you added a subwoofer amp after the stock amp? Are you using the high level inputs on the 2nd amp? If not, that could be your problem. In that case you would want to use a pre-amp signal to your new subwoofer amp.