QuestionI have an alpine v12 600rms digital amp and only 2 preouts on my deck but 2 amps. my 2nd amp mtx 400.2. the alpine has a pre out so i connect alpine to deck and mtx to alpine. But for some reason I'm getting a humming, not if I connect mtx directly to deck, and only in the mtx spkrs when connected to alpine preouts.
Also I have a pioneer DEH-P3000IB and with my system all connected working fine. I re arranged my subs and ruined my rca cables in the process maybe shorting them? not sure. now the deck hums from all preouts any ideas why? I have a good ground and good rca's now I did my best to check the wiring all looks good. It all worked fine prior to my rearranging the subs, I'm at a loss. Can shorting the rca's cause permanent damage like that? what happened is the end of the rca cables were loose and when I pulled them from the amp the gold male end came right out of both ends so if that was shorting??? The regular speaker wires all work fine no humming. And yes when I start the engine it gets worse for both issues! Thanx in advance!!!
AnswerHi Scott,
Noise issues are always the hardest to find, insolate, and fix.
Start with a fresh set of RCAs just run through the car for testing -- don't bother hiding them under panels or anything just plug them in and listen.
Another option is always grounding. You might think your ground is good, but some amplifiers are more prone to bad ground noise than others. Make sure your ground wire is cleanly connected to bare metal that is not welded, and preferably < 18" long. (Even shorter is better.)
Make sure your RCAs are not running parallel to any major power source (such as the amp's power cable).
Shorting RCAs very very rarely fries them as the voltage running through them is incredibly low.
Unfortunately, your only option is to go step by step through each of the parts in the circuit until you find one whose replacement eradicates your problem.
Try just fiddling with wires too -- if that affects your noise, then you might have a wire that needs replacement.
Justin
