Thumping noise (long)

Reply Subscribe

Thread Tools

Search this Thread

09-01-2004, 05:56 AM

2 8's AKA Jeepbeats

4000 Watt CAFz'r

Thread Starter

iTrader: (19)

Join Date: May 2001

Posts: 5,644

Hey, my bro has a Clarion DXZ-535 deck, a Punch 40 running some mids in the doors, and some 3.5's in the dash, and an MTX 251D mono sub amp running a single 8" sub in his 1986 Toyota pickup. Before this, he was running my RF 400x4 to the mids and the sub, he had another Sony deck in there, and had no noise problems. We swapped in the Clarion deck (virtually new), and then did the RF amp and the MTX amp. He has 4 awg that I ran for power, and each amp has an 8 awg ground that we ran together to a common point on the rear wall of the cab (single cab truck). The ground has had the paint removed, and is held on tightly by a nut and bolt with a lock washer. We tested the ground, it was reading around .4-.6 ohms, then we swapped the RCA's, and it still came back, but the only noise cam from the sub amp (MTX), no problems with the Punch 40. He used both sets of RCA's before without any issues, one for the amp, one for his cd changer that he ran before. With the truck on, he is getting a solid 14 volts at each amp, the remote wire is split between amps, and we have not used a relay. One thing is that the remote lead on the RF amp is a bit loose, on the PC board itself, and sometimes the RF shuts off, even though I attempted to solder it before (am going to try hot gluing it in place). I would think that if the remote was the problem, both amps would just shut off, wouldn't they? Here is the problem, he will be listening to the system, and he will start to get a bad thumping noise through the sub only. He exchanged the amp for another one, it happened again. I think maybe he should try another spot to ground to, it is better for each amp to share the ground to eliminate any chance of a ground loop, is it not? Use a star washer, also? Maybe try a 4 awg ground? Another possiblilty is that the deck has a problem with the sub output. I could always try another source, correct? Any info would be appreciated. Thanks!