Odd sounding sub

[Jaminizer]

I have a 2002 Audi TT with the upgraded (factory) Bose soundsystem and I have installed an aftermarket amp and subwoofer. It worked great and sounded perfect for about 2 years. I then had it out of the car for a few months (due to a few trips to race city), and after putting it back in, it sounds strange. It was instantly noticable that muffled voices are playing through the sub, even when I set the low pass filter below 80Hz. When I lower it to 40hz, the voices are mostly gone, but the sound is still muffled/gurlging/farting... it just isnt clean.

I have:
- Peripheral Sven2 Line Out Converter
- JL 500 1v2 amp
- 2 JL W3 10 inch subs

I kept the factory system in place, and ran wires from the back speakers into the LOC and then the RCAs from the LOC to the amp's Input section.

I have tested the system with another set of speakers and the same problem occured, so it is not the subs.

Any ideas what could cause it, or advice on how to approach pinpointing the cause without breaking the bank? ... I am thinking the LOC might be to blame ... but not sure if those things ever fry/overheat/fail.

[Graham_A_M]

Your RCA's may have been damaged/pinched somewhere. I doubt its your LOC, but that is a possibility. If there is wiring exposed anywhere on your RCA. then random radio waves & other electrical interference may be whats causing this. Try running a set of RCA's that you know are good, and see if this isolates the problem, if so: thats what it is. If not, try powering your sub amp using an Ipod/Iphone or home theater receiver. If THAT fixed the problem: its the LOC.

[Jaminizer]

I tried powering the amp with an iPod and a headphone-to-RCA adapter and the problem still occurs.

I managed to track down a friend who has a monoblock/sub that wasn't installed in his car. So I tried a few different combinations and found my subs are great, the LOC is fine, my signal is fine... it is the JL 5001v2 amp that is causing the problems. I am quite surprised because I have never really pushed the amp too hard. :S

I see a lot of threads on 'amp repair shops', so I am going to look into that. Since the amp is still relatively functional, I am hoping the repair isn't to expensive.

Thanks for the help Graham_A_M!