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I have recently begun hearing a fluttering noise from my subs, which becomes more apparent when I turn up the bass remote knob. There is also a thud sound when the amp turns on or off. BTW, I'm running 2 Comp VR dual 4 ohm off of an Arc 1000.2t with an Audio Control 3xs.

Naturally I thought there was a problem with the ground, so I checked that and everything seems fine. I also checked the RCA's going to and from the crossover. I even adjusted the gain on both the crossover and amp, but that just resulted in less volume of both music and noise. I will pull the HU out tonight and see if the RCA's are loose or something, and I may try Ryan's tip and use some electrical tape on the RCA's.

Another interesting thing is that my component speakers sound fine; no engine noise or anything. The 2 amps do share a ground point with the crossover, but there doesn't appear to be a ground loop problem due to the components being ok. At this point I'm lost, but I'll keep trying to find the source of the problem. If anyone has any ideas please let me know. Thanks.

Does anyone think there is a problem with the amp? I sure hope not

check your amp turn-on wire...i had the same thing happening to me as far as the popping sub when you turn your car on/off and it turned out to be that the amp never turned off so that pop was the signal or something...still never fully understood what it was but i know after i fixed the remote wire it stopped

I will be sure to check that out.
The amp does turn off, but I forgot to mention that when it turns on the power light flashes quickly and then slows down to show a constant light. I'm not sure if it is supposed to do that or not, but I will check the manual and try to find out.

I'm thinking it's either a defective sub amp (that thump can be caused when the amp is damaged internally) or the subs have a problem, but without hearing it I can't say for sure. I'd bet on the amp if I had to pick one of the two.

KikiTheCat wrote:I'm thinking it's either a defective sub amp (that thump can be caused when the amp is damaged internally) or the subs have a problem, but without hearing it I can't say for sure. I'd bet on the amp if I had to pick one of the two.

I was hoping that wasn't the case. Thanks for your help. I will swap out my sub amp with the one for my components and see if the problem persists. I'll probably try a different grounding point for the amp too.

If I recall right my subs made a thud when the amp turned on and off.

I never seen it as a big problem.

Now the noise your talking about coming through the subs.

If I had to guess I would say it has something to do with the input voltage coming out of your crossover. Look at your crossovers manual and see what the RCA output voltage is. I think the KAR series can only handle like 8-9 V input...

Or better yet try bypassing the crossover on the sub amp. The KAR amp has the required stuff built in already, so no need for it there!

I checked it out some more tonight and I think it is the amp. I hooked up my component amp and it powered the subs fine with no noise (the MTX 302 actually pushed the subs pretty well). The constant fluttering noise is much louder when the engine is running; I can't even begin to explain that. The noise disappears when I turn down the gain or the bass remote knob, so I may have to live with a little less bass for a while. I think the problem started when the ground came loose on the amp a few months ago and the current arced and burned the negative terminal. I guess I'll have to send it in to arc for repair

Did you check into the voltage side of it?

I didn't check the voltage because I don't have a meter. What would I need to check it?

Look up product specs for the crossover and amplifier.

Se what the line out Voltage of the crossover is and what the maximum input voltage to the amp is.

I had this problem many years ago with my Audiocontrol 3XS eq/line driver. It actualy over drived the amplifier and had some strange (Yet I now forget) effects.