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.
Sound coming from JL Audio F 113
I have had a weird noise coming from my JL Audio sub a few days ago that sounded almost like white noise, or maybe a wind tunnel. It continued when I turned the sub off, not stopping until I unplugged the unit. I plugged it back in and It has worked fine. I heard the sound again for a few seconds when I turned it on today. Anyone have any idea what would cause this. Could it be a capacitor issue? I hate the thought of sending it in for repair.