Alt Whine With Sub Amp...

[The_Grimy_One 10+ year member]

Ok, so I have a fairly simple set up. 2 way component set on 2 channels of a 4 channel amp.

And a single 12 on an amp at 4 ohms...

Well when I disconnect the RCAs from my sub amp, I have absolutely no noise. However, when the sub amp is connected, I get a decently loud alternator whine.

What might cause this? I thought that alternator whine was only introduced through highs when there is a bad ground or interference with the mid/highs amp... Didn't know the sub amp could introduce noise through the mids/highs. I have the power wire running on the opposite side of the car as well.

What should I try first to tackle this? Thank you in advance for any advice.

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[The_Grimy_One 10+ year member]

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[The_Grimy_One 10+ year member]

Thoughts?

 

[maylar 10+ year member]

Grounds, grounds, grounds. Relocate the ground wire for the sub amp. Ground loops happen when the HU ground is at a different potential than the amp's ground and ground currents flow through the RCA cable's shield. And yes, the sub amp can most definitely have an effect on that. I had a similar problem on an old install and the only solution was a ground isolator. But the car was old and rusty and the trunk was far from being a solid ground no matter what I did.

 

[The_Grimy_One 10+ year member]

Grounds, grounds, grounds. Relocate the ground wire for the sub amp. Ground loops happen when the HU ground is at a different potential than the amp's ground and ground currents flow through the RCA cable's shield. And yes, the sub amp can most definitely have an effect on that. I had a similar problem on an old install and the only solution was a ground isolator. But the car was old and rusty and the trunk was far from being a solid ground no matter what I did.

U actually used a ground isolator on the sub RCAs? Thanks for the info. I am gonna step up all my ground before I put my new sub stage in.