I recently installed an aftermarket sub and amp and everything works good except for this 'hum' i get. I moved the RCA's as far away as possible from the REM cable and its still there. When i start the car the subs and the hum follow the exhaust note of the car and when I hit a switch like the windows you can hear it in the subs. Any possible solutions?

 

What wiring did you use? You'll want decent, shielded signal wire going from your head unit to your amp, ideally running on the opposite side of the car from your power lines, but as long as they're not right next to each other you should be ok.

Do you have the factory Bose system? If so, I believe the HU on those has a very low pre-out voltage, which leads to a lot more translated noise when amplified with an aftermarket amp.

 

I am using 8 gauge wiring from those rockford fosgate amp wiring kits so its extremely strong stuff. I have the stock bose system to

 

Are you using the same signal wires from the factory HU to the amp? You may want to consider rewiring the amp if that's the case.

Where are the power lines wired in relation to the signal?

 

I actually dont have any wires running from the stock HU, i spliced into the stock sub/amp. I tried to get the power lines as far away as possible because I thought that could be the problem as well and there a good 2 feet away from each other and the hum did not get any quieter. Im completely stumped as of now

 

I think you're issue is in the factory wiring. Like I said, the stock deck has a low voltage pre-out on it. You can try wiring a line output converter right behind the factory HU and then run shielded RCA's back to the amp, might help.

Also, make sure you have a solid ground out of your amp.

 

Maybe I didnt explain the wiring like I should, my fault. I have everything wired to the trunk. My RCAs are plugged into a line output converter which is spliced into 4 of the stock sub cables. The REM is spliced into the stock amp power wire. The ground is as solid as it gets.

 

Ahh, ok. For some reason I'm thinking that you're replacing the Bose amp with a 4 channel amp, but you want to run your stock amp with your new aftermarket to power your sub (which I should have understood from the fact that you're installing a sub...slow night for me).

That being said, my first recommendation for you would be to run a new power line to the aftermarket amp straight from the battery, make sure the contact point for the ground is sanded free from all paint and imperfections - it should be metal on metal, and splice into the factory wiring before the amp with a LOC, running the RCA's to your new amp and the spliced signal wires to the factory amp.

Involves a lot of rewiring, but is probably better in terms of quality and reliability than just splicing straight into your factory connections.

Edit: you are splicing from the factory sub cables? That means you're using an amplified signal (from the factory amp) as a pre-out for your aftermarket amp...?

 

What you explained is exactly what I have. Are you trying to say that splicing into the stock sub was a bad idea because it is already an amplified signal?

 

Right. As you said, you're splicing in to the factory wires between your factory amp and sub. I'm saying you'll get better quality splicing in from before the amp.

 

Any recommendations on what I should splice into that can give the amp power?

 

You'd be better off running the wire directly and not using the factory wiring - not sure how much power the factory wires can handle. But it shouldn't be too much of an issue to splice off the factory amp power.

 

Alrite ill use that as a last resort, thanks for all the input. Any other suggestions on things I can try?

 

Double, and triple check your grounds. Including the factory amp ground.

Other than that, you haven't done anything to the factory wiring anywhere in front of the trunk, so I would focus your initial efforts strictly on what you have changed - just moving that LOC to before the amp and making sure you're using shielded RCA's.

 

yup grounds are you issue

im running two 4ga wires right next to 4 channel rcas, no problems at all

I have had the same issue in the past, and moving your ground to a better spot is the fix.