Unwanted Thump Noise

I previously addressed this issue in this forum under this thread.      My problem is that I am having a random, deep-sounding "thump" that randomly comes from my sub. It sometimes is just a single "thump" but it has come in twos, threes, and even more in very quick, machine-gun-like sucession. This is a real booger of a problem. I thought I had solved the problem but I was incorrect. I have tried everything I know to do and I have checked every connection multiple times. Tonight, I even ran a 4 gage ground wire from my amp directly to the negative battery terminal just to eliminate faulty grounding. No dice. The thump noise is still there. I have also disconnected all inputs to my amp and even the outputs except for the sub's speaker wires. In short, the amp had a 12V turn on wire, power wire, ground wire, and a single set of sub wires going to my sub. I did this to eliminate the head unit as a source of thump noise. The thump was still present which told me that the head unit was not to blame. The only components left in the equation are the sub and the amp. I am betting it is the amp but I would like to here some of the expert's opinions on this problem. Please let me know what you think. Thanks, Mike My Installation My Recent Posts In The Polk Audio Forum2000 F150 Supercab Lariat, Alpine CDA-9831, Polk MMC570 in Doors, One Polk MM2104 Sub, One Polk Carbon C400.4 Amp.

John 3:16

I was having the same problem. It was my amp. If you have another amp just switch it out and see if the thumping goes away.'85 Toy

Thanks for the reply! What type of amp did you have? Was it a Polk?2000 F150 Supercab Lariat, Alpine CDA-9831, Polk MMC570 in Doors, One Polk MM2104 Sub, One Polk Carbon C400.4 Amp.

John 3:16

No, it was a Crossfire amp.'85 Toy