Sound coming from JL Audio F 113

If it's under warranty, I certainly would send it back to JL for repair.

JL makes great subs, but if my experience is typical, not enough work is put into durability engineering in the design. My two F112s have been back to JL a total of four times (twice each). To JL's credit, they comped the last repair, even though the sub was about 12 yrs old.

Stuff fails. But when its a 100-lb subwoofer, the failure is really painful.

A few weeks ago the amp in one of my six year old F113V2's died, when turned on just made a "thump, thump, thump..." sound.

I contacted JL Audio and they have a "fixed price" update for out-of-warranty subs, where they not only repair the unit, but they also bring the componentry up to date with the updates they've made over the years.

The JL rep sent me detailed instructions on how to properly remove and reinstall the backplane amplifier.

I am super pleased with the service I received from them, I'd recommend you do the same.

I will check, but I am pretty sure the sub is out of warranty. What is strange, is that I hear the white noise when the sub is switched to off. When I switch to on, it stops.

Sounds like some caps going bad. There is a switch on the back to lift the ground as well. I would flip the position of that if you haven’t already and see what that does. Mine has been out of commission for several years. I finally pulled the plate amp and am planning on sending it in for repair. It’s $450 plus shipping.