Dark Shark

So I just installed a new amp under the drivers seat to power the rear 6x9's, I finished and listened to it with the car off and everything sounded really good and was working properly. Then I turned the car on and this ugly buzzing/whining noise starts coming from the amped speakers. I ran the power and RCA's away from each other so I wouldn't get noise that way, but I'm not sure what's causing this. The noise changes pitches with the engine RPM's too, sooo.... Car Audio guru's, Any Suggestions?

UrS0NvS

you got the dreaded alternator whine my friend. you need a ground loop isolator, i think that is what it is called.

I'm sure DTN will answer this soon.

Nex

Its your grounds. If you hear the buzzing change as you drive thats pretty much a dead giveaway. Perhaps you chose a bad ground spot?

Dark Shark

I started researching ground loop isolators and a few people have said they lost SQ when they used it sad.gif I'd really hate to lose any quality of my music... But that was a RadioShack isolator so possibly its just RS's crappy product.... Id SO buy one if I knew it didn't hurt the SQ. Anyone bought one before?

Hmm, I guess Ill try a new ground spot to see if that helps...

DTN

A ground loop isolator is a band-aid. The best thing is to move your RCA cables away from the power wire. Usually alternator whine is caused by the power wire running right along side of the RCA. If you can run them as far away from each other as possible, and have them intersect only at 90 degree angles, it should eliminate that noise.

Rixshark

My power line runs on the driverside, RCAs on the passenger side. No distortion or noise at all.

DTN

^^ same with mine, but reversed. I've got a video line for my backup camera running by my power wire for my amp. When the bass hits, the video goes fuzzy.

I didn't think video would be effected. It's not an issue though. The only time I use my backup cam is in a parking lot. Shouldn't have the bass up anyways.

Nex

weird, i have my rca close to the power line and i dont have this prob, i actually changed the ground spot and the buzzing went away.

If its not buzzing anymore should i just leave it? will it be affected later? im confused

Dark Shark

I re-grounded everything, even cut the HU's ground and ran it to the amp to make sure it was grounded properly, bought new Signal wires, checked all the connections.... Still get the whine when I rev it. I even tried a Ground Loop Isolator a few weeks back... COMPLETE CRAP. I tried 3 different ones and they all got rid of the whine, BUT also got rid of all the quality in the music as well (Bass didn't hit, Highs were crackly). So I just decided to live with it...

Until Today. While cruising around CarAudio.com I ran across this thread-----> Pioneer HU, Alternator Whine Fix If you are getting this whine and you have a Pioneer Head Unit, TRY THIS FIRST! It will save you alot of hassle if you did indeed wire up everything correctly the first time. I wrapped that wire around the outputs and it fixed my problem completely. I like Pioneers products but I have to say, this was retarded that I should have to do this to have it work properly, but I am glad it is finally fixed.

For those of you too lazy to click the link:

radu_rd2

Glad you made it work. Thank you for posting the solution. I also have a pioneer HU and thinking of adding an amp; I have no idea how to mount it under the seat though - any tips on that? Is it straightforward, just remove the seat and there is enough room? How did you mount it in place, did you drill any holes for screws or anything?
Or you could do a `how to install an amp under the seat' DIY puppy_dog_eyes.gif fingersx.gif