When my car has been off for awhile and I turn it on, my subwoofer and amp emit a loud bass tone at near full volume. I thought at first it was a poor ground, but I have tried everything to correct that, and after watching videos online about ground loops/poor grounds, it seems like a different sound. The issue gets weirder in that when I open my trunk, the sound goes away instantly, or if I roll my windows down, a few seconds later it will usually stop. It's as if pressure builds up and causes some kind of feedback/reverb...
Anyone know what my issue may be?
I am running a DUB a11000b amp with a 12' Kicker Comp sub in a ported box, connected to factory Accord stereo via a line level converter. The sub and amp are located in the trunk. Main POS+ line ran directly from battery using large gauge wire (forget gauge, but definitely big enough). Ground is connected directly to chassis, paint sanded. Ground has been checked using a megger and is more than sufficient.
