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I recently decided to upgrade and rearrange my setup and now im experiancing an odd problem. My setup is now an eclipse cd 7000 HU sending out a full range rca signal to my AX606.2. Anyone not familier with this fine piece of ampage it is a 6 channel amp with a built in crossover (its actually a 404.2 + the pro art 50) so the 606.2 breaks up the signal into highs, mids, midbass then it passes on the bass through rca into my 600.2 which powers my subs. The subs are wired serial into a 4 ohm load bridged onto the 600.2.
I had my 606.2 and the 600.2 checked by a local dealer. He found a loose rca on the 600 and fixed that for me. He had the 606 on the bench and was tapping away at the gains and crossover settings while switching back and forth between the channels. He told me the biggest issue hes seen with this amp is that the switches and crossover knobs will tend to cause distortion when adjusted but he was very surprised by the overal condition of the amp. Never once did it make any noise not expected while he had it on the bench.
so I get everything setup properly and find that every so often my system goes nuts (for lack of better term) and makes a ear blasting pulsing sound, it almost sounds like pure voltage going across the lower range speakers. Including the sub woofer which is connected via rca and on a seperate amp.
I double checked all my speakers thinking it was a short and found my midbass connection had fallen off in the door. Great i think , problem solved. Then it happens agian. So I tape up all the speaker output connections on the back of the HU and tape up the extra rca's on the back hoping that maybe they were shorting. This seemed to have had an effect because now instead of it being a long continous sound it will only "pop" once and go back to music. Im wondering if I didnt tape the HU speaker outputs well enough and they are still shorting or if there actually IS something wrong with my 606. I cant make the system cause the noise by any means and there is nothing connecting cause wise the noise at all times. One time i was turning, one time i was just starting my car, one time I was adjusting the gain on the 606 and the last time I was turning the volume up on the HU. Im at a lose. Any ideas would be great.

I found that my ground wire was loose and might have been speradically loosing connection. Obviously that would cause a problem, but would it cause the type of sound that im describing ?

My truck did this once and found that the gains on my amp were set too high. Once I lowered them a bit then bang there was no more problem.

The gains are set as low as possible since the HU puts out 5v max and the amp takes 4v max.

Dragon_fire wrote:I found that my ground wire was loose and might have been speradically loosing connection. Obviously that would cause a problem, but would it cause the type of sound that im describing ?

Yes, a loose ground can cause all sorts of strange things. The ground is no joke, you'd better make sure it's adequate and secure, before something worse than a "pop" occurs.

okay, so far after firmly securing the ground I have not experianced the issue agian... YET. However, im still a puss and scared as hell about hearing that sound agian. So I did what anyone else wouldnt do. I yanked the ground wire while the amps were playing, lo and behold they just shut off. So my new question is could a momentary short caused by the ground wire bouncing off the distro block cause the amps to go nuts like I described ? I'm thinking this is what was happening because I saw the burn marks caused by jumping voltage on the distro block.