A few weeks ago, I did a complete stereo overhaul in my car. Thanks to all the info on the forum, the install went smoothly... it was even fun!

However about a week ago, I lost pretty much all output from the sub. When I'm right next to it, I can barely hear it although it was damn loud when it was working right.

Following JL's guidelines, I originally set the gain so I was seeing ~44V output, now I am getting about ~10V, so it's not the speaker. Also, powering the sub with the other amp produces significantly more volume, even though it's 1/3rd the power.

I get the same result when I swap inputs to the amp, so I don't think it's the head unit or wiring.

I checked the x-over settings on the amp, and it looks right. Turning off the low pass filter didn't make any difference.

To me it seems the amp crapped out on me, I bought it used off ebay so it's not out the question. Anyone have any good ideas of things to try before I go off and buy a replacement?


System specs:
Pioneer 7900BT
Modifry DCI
A/D/S 6.5" components
10" eD sub in a WLaurent enclosure
JL Audio 300/2 for components
JL Audio 500/1 for sub

 

I would suggest double checking the amp's ground. Make sure it's solid (use an ohmmeter). Also, double check the fuse(s) for the amp. Try replacing them (I know I've had issues where the fuse wasn't exactly bad, but because it had arced between the fuse block and the fuse, there wasn't a solid connection for passing power).

Other than that, yeah, it's probably dead.

 

Thanks, I'll check the ground tonight.

JL's amps don't have a fuse in them, so it's not that.