Loud nasty engine whine that mirrors rpm.

[An-i-no 86]

Ok so some of you may have read my other thread about the RF amp. Well I put my AQ 4X90 back in and bridged it on my fronts and got a naaaasty engine whine.

I checked the ground, it was tight.

I tried both my sub rca's and another pair of rca's they both make the noise.

Sub amp makes no noise.

When I disconnect the rca's the noise stops.

I moved the ground so that my sub amp and the AQ's grounds were seperate, still got the noise.

The noise stays loud regardless of head unit volume.

I put the RF amp back in and it makes the same noise.

I'm very clueless and frustrated. I followed the noise guide but none of it helped.

Edited October 28, 2011 by An-i-no

[Quentin Jarrell 671]

Unbridge the highs and see if it stops

[jcarter1885 995]

Hook an Ipod or Mp3 player up directly to your highs amp while the car is on and see if it still makes the same noise, if it doesnt then it could be your radio.

Was this noise there when you first hooked up the Rockford Fosgate amp?

[Shogen 325]

Hook an Ipod or Mp3 player up directly to your highs amp while the car is on and see if it still makes the same noise, if it doesnt then it could be your radio.

Was this noise there when you first hooked up the Rockford Fosgate amp?

this... Jay helped me with this before..

[95Honda 486]

There is a difference in ground potential between the equipment. The current travels on the RCA's to try and level out the difference. There is an AC component in the current from your alternator and that makes it through the coupling of the different amplifier stages.

Only way to get rid of this is to equalize ground potential.

If you have a long piece of say 4 awg cable, hook it up to the HU ground and your amp that is making the noise. Keep the original grounds in place. If the noise drastically decreases or goes away entirely, you will have to find a way to permanently do this. Could mean a big piece of 4 awg.

This is the problem 99% of the time if the equipment isn't bad (broken).

Also, when you use this cable, don't be afraid to try it on a few different ground points of the source (h/U). You could try touching it to the case or the RCA grounds (outside, not the center pin).

Good luck.

[An-i-no 86]

I will try both Audibel & Jay-cee. I have to go buy of those cables though. I'm in the house chillin now I had to get far far away from car audio.

[95Honda 486]

IPOD is waste of time, if you unhook the RCA's and the noise stops, it will not be there with an IPOD.

[An-i-no 86]

So what could it be Honda?

Edit: reading fail

Edited October 28, 2011 by An-i-no

[An-i-no 86]

When you say "hook it up to your amp that is making the noise?" Do you mean into the terminal or ground it where the amp is?

[Tirefryr 1,742]

Do you have a Pioneer HU?

[95Honda 486]

The battery (-) terminal. Or the RCA ground if that doesn't work.

Under NO condition connect anything but a speaker to the (-) speaker output!!!! You could fry the output stage of the amp if you ground out the speaker (-) terminal!!!

[Impious 1,476]

Noise Troubleshooting Guide

[An-i-no 86]

Tirefryr, nope I have a Kenwood.

Impious I tried that but i got all the way to he point where I need someone else's car and couldn't continue.

Honda, I meant the ground terminal on the amp like power and ground. Sorry for the confusion, thanks for the help.

Edited October 29, 2011 by An-i-no

[ricksi30 923]

Do you have a Pioneer HU?

Same issue with some Kenwood units. Look up "pico fuse pioneer" and you'll find info on it.

[An-i-no 86]

I'm familiar with the pico fuse issue. Are you sure that carries over to Kenwood? It's a KDC-X794 if you need to know.

[ricksi30 923]

I can't say that I'm 100 percent sure but I do remember hearing about a similar problem with Kenwood. I could be making it up though haha. Just trying to help. Ground the rcas behind the hu and see if it goes away.

[ricksi30 923]

And the fact that you were switching amps also hints at it being that.

[An-i-no 86]

I guess it's worth a try. I'll look into it tonight

[ricksi30 923]

Cool really hope it solves your problem. If not you can check it off of the list at the very least.

[An-i-no 86]

Amps switched, rca's grounded, music loud and clear! Thanks everyone for all the help.

[jcarter1885 995]

Glad you got it fixed, which amp are you using?

[An-i-no 86]

The Audioque. I have mixed feelings about the Fosgate, it sounded fine on my rears (Punch 6.5 components) when I tested it.

[jcarter1885 995]

Are you running it bridged, if so how do the speakers output compare to it being unbridged?

[An-i-no 86]

Bridged. Gains and xo's not fully set so it clips a little on midbass heavy songs. For now I just have them crossed high. They have much more impact now. The drums make you blink and the ticks in rap songs are very loud. Midrange is super super clear. I might not buy new fronts for awhile now. It completely changed my plans.

Lolrant.

[ShagggDiesel 25]

I had this problem with a Hifonics Brutus 2610D.. There was something wrong with the inputs on the amp. I bought a ground loop isolator for like 8 bucks and it eliminated the problem. However, I think there was some sort of low end rolloff built into it because I didn't feel like the lows picked up as good with the isolator installed. Just an idea if you're still wanting to use the old amp.