I added an amp and this happened...

[Micky7]

Hey, so the other day I came across a nice pair of 5x7's that I wanted to throw in my car because I had the room, so to power them, I put in an old amp I had lying around, except it seems to cause alternator whine at times....

Originally I just had one alpine mrp-m350 amp running my subs for me, no problems. When I put this other amplifier in ( kenwood kac-625 i think) all I did was split my 4gauge power line with a distro block into to 8's and sent one to each amp, and the grounds are just the opposite, except no block. I left the ground attached to my frame where I originally had it. Anywasy it seems that at night when I have the lights on, which are pretty strong I get some alternator whine.... is this a sign of a strain on my cars electrical sysytem? or is this simply some sort of ground loop I have to work out?

- my power and rca's run opposite sides of the car

- there were never any problems with only the one amp

- the rca's are split in the trunk to give each amp its signal

if you needed to know anything else just ask, its a pretty high pitch noise, bot from the speakers, from the alt im sure. Just wondering about all possible causes / solutions, Thanx guys

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[allyourblood 10+ year member]

i've never experienced this myself, but i've read a half-dozen posts that mention replacing the RCAs can solve the problem. try out a few different brands...

abe m.

 

[nosaj070 10+ year member]

Very possibly could just be the amp, many amps are more susceptible to alt whine. Try it on your other one, and reground it.

 

[InhumanAcura 5,000+ posts]

One amp is simply less efficient than the other, Im telling you man, your alternator is your weak link.

 

[nosaj070 10+ year member]

One amp is simply less efficient than the other, Im telling you man, your alternator is your weak link.

First how does efficiency induce noise into the system, second the alternator would not just magically induce more noise due to a higher load.

 

[InhumanAcura 5,000+ posts]

First how does efficiency induce noise into the system, second the alternator would not just magically induce more noise due to a higher load.

I appaulagise smart one, no need to magically be a dick. When I saw alternator whine I assumed it was the alternator whining not alt noise coming through the system.

Having metal shielded rcas is an easy fix.