engine noise (yes again)

[brandontw 10+ year member]

i am no stranger to installing car stereos, i have installed in 2 of my cars and 4 of my freinds, and have had slight problems with engine noise, but were easily fixed with all of the regular solutions. But my current car is the DEVIL! it has engine noise that just wont quite. I have:

-Regrounded amps(5 times)

-Ran RCA's separate from power(supposedly a myth, but still tried it)

-Got new RCA's (Esoteric noise- destryoyers)

-Tried other amps(4 different amps)

-Bought some of those ground loop isolater filters (1 for each pair of channels)

-Yelled at it

-Prayed(and im not even religious)

i am at my wits end, asked a local car audio shop(i knew more about stuff than they did), and they were not helpfull. I am thinking of running a wire from my HU's Ground to the ground point of my amps. but this seems like overdoing it. the ground loop[ filters softened it, and i thought i could stand it, but its just too annoying!I have a CDA-7995 HU, and my 4 channel amp is now a hifonics zx6400.

any ideas?

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[squeak9798 5,000+ posts]

Tried grounding your amp & HU directly to the battery? If you do that, and you still get noise, then there is a more serious problem.

Also, where is your gain set? If your gain is up high, you might simply be getting noise from the amp.

 

[brandontw 10+ year member]

gain is at less than half, and like i said, i have tried other amps.

my amps are in my trunk, so grounding them to the battery wouldent be practical, unless i had a batt back there

 

[bonesninja 5,000+ posts]

gain is at less than half, and like i said, i have tried other amps.
my amps are in my trunk, so grounding them to the battery wouldent be practical, unless i had a batt back there

it would be practical if it worked right? Did you set your gains by the tutorial or just by ear because you could still have the gains set too high if you didn't do it with a multi-meter.

 

[squeak9798 5,000+ posts]

Unplug your RCA's from your amp. Is the noise still there?

 

[brandontw 10+ year member]

Unplug your RCA's from your amp. Is the noise still there?

good idea, lemme go do that right now

 

[brandontw 10+ year member]

ok, im back, and the noise went away when i unpluged the rca's, so this means that it is engine noise, not just amp noise., but how can i get rid of it?

and grounding the amps all the way back up to the battery would be another 50 feet of 2 gauge wire, and a buttload of work. not worth it.

so would my idea of grounding the hu to the amp's ground be a good plan to try?

 

[squeak9798 5,000+ posts]

Have you tried using a different source unit? Buddies car, walkman, home stereo, computer/laptop....anything other than your current HU? And have you tried using your HU to send the signal to a buddies system?

What kind of noise is it? Are you absolutely sure it's alt whine (changes pitch as the engine revs)?

 

[DBfan187 5,000+ posts]

ok, im back, and the noise went away when i unpluged the rca's, so this means that it is engine noise, not just amp noise., but how can i get rid of it?

I think your HU is the culprit here. Try regrounding it.

 

[Scarenius 10+ year member]

I can vouch for re-grounding your HU. I just did that tonight. Your HU is only running like, 18 guage stock wiring with a million terminal points. Lots of resistance. Just run something like 16-10, anyhting bigger than what you have, directly to a solid ground and battery positive. It killed the alternator whine in my car, and I'm running 2 amps, and possibly a bass knob in the future.

 

[brandontw 10+ year member]

yes i am positive it is alt whine, i have heard it before and that is what it is, the more i think about it the more i thnk that it must be the HU, i guess this weekend ill be ripping it out and regrounding it, i hope that will fix it, i think ill run like a 16 gauge wire all the way back to the trunk and ground it to where the amps are