Alternator Whine after amp/deck install - 986 Forum - The Community for Porsche Boxster & Cayman Owners

BluBYou · 11-28-2006, 06:04 PM

I installed a Soundstream amp and Alpine 9856 deck my 03 Boxster, and have been getting a lot of alternator whine from it. I have tried re-grounding the deck to the chassis, regrounding the amplifier (I have it tapped off a bolt in the front trunk).

Two weird factors about this -- when I have the key in and I push the gas pedal in, I can hear somewhat of a whine from the speakers, and it varies with how far I push it in. Strange. Also, when I plugged in a ground loop isolator to my RCA's, and the whine got WORSE.

I have the amplifier mounted in the front trunk, and the power cable runs from the battery down the passenger side of the front trunk and right into the amp. I don't think there is a way to separate these and keep the power and the inputs from running separately when installing it here.

Any advice for me? Help!

Also -- which antenna adapter will I need to plug into the stock antenna? I can't find one locally.

Playing music loud to not hear the whine--Matt

insite · 11-29-2006, 04:16 AM

you really need to run the power cables and the input / output cables on opposite sides of the car if possible. other options:

- get higher quality RCA cables that have groundable shielding
- get a power line stabilizer (noise reducer) that wires inline with the positive
positive power cable running to the amp
- make a torroid inductor inline with your power cable (loop the power cable
through a circular magnet multiple times

mjstallion · 04-26-2007, 02:16 PM

I just got my system installed, and there was a little bit of whine when the music was very low or when the navigation was going. I went back to the installer and he put in a filter and now there is no whine.

It seems that filters are viewed as bad on these boards, and I was just wondering if I should go to a different installer and have him remove the filter and fix the whine by other means...

insite · 04-26-2007, 02:29 PM

Quote:

Originally Posted by mjstallion

I just got my system installed, and there was a little bit of whine when the music was very low or when the navigation was going. I went back to the installer and he put in a filter and now there is no whine.

It seems that filters are viewed as bad on these boards, and I was just wondering if I should go to a different installer and have him remove the filter and fix the whine by other means...

it depends on how powerful your amp is. if you went to a cookie cutter type installer (best buy, circuit city), they won't re-wire it for you. if you went to a high end place, there's really no excuse for not properly routing / shielding the cables. if your amp is low power, the filter is fine. if you're concerned with overloading the filter, add another one in parallel.

chitowndad · 05-18-2008, 04:24 PM

Ok, so when I installed my Avic D3 I grounded the parking brake and mute to the radio ground and had the same issue. When I redid the mute and parking brake ground to a metal part on the frame (actually grounded it to the area where the old amp was installed on the frame) my whining sound went away! Go back and retry your grounds!

-Steve

chitowndad · 05-18-2008, 04:28 PM

I forgot to mention that I also tried grounding to the brown wire behind the drivers front headlight and I also still had the whining sound. That brown wire is the ground from the head unit. It wasn't until I found a fresh ground source did my whining sound go away. Now I just need to figure out why I'm getting a pop sound when I turn off the car!

Daryl80 · 05-20-2008, 12:09 AM

Hi chitowndad

I too faced that dreaded alternator whine. Ended up pulling everything apart, as I just had no idea where the fault could have been

Never occurred to me, that it was the FACTORY ground!!! Aaargh,

Anyway, can you please advise on where did you hook your new ground wire?

More so, do you have an amp?? I'm trying to install one in the front boot, but am not seeing anyway around avoiding the battery.

Thoughts?

Thanks

Daryl

rick3000 · 05-20-2008, 04:19 AM

That is weird because normally, the whine gets worse at louder volumes, also the whine increasing with RPM is normal (mine did that). I would recommend a few things, that may help: ground everything to the same ground point, buy a high quality ground loop isolator, and/or like insite said, get higher quality cables.

chitowndad · 05-20-2008, 06:56 PM

For the Avic D3 mute and parking brake bypass I simply grounded to the bracket for the old amp. Worked for several days but oddly, my whine came back today, so I'll need to find another source! Grrr.

I'll mess more with this over the weekend.

-Steve

chitowndad · 05-21-2008, 05:47 PM

Ok, so I bought a ground loop isolator from Radio Shack (hate that store) and my humming is gone. I recommend this solution.

-Steve

boxs2000 · 05-21-2008, 10:23 PM

Alternator whine can also be reduced by adjusting the line level input on the amp. Sometimes when the amp is turned up too high it creates this. Check ground sources, preferably only ground the audio units to one round and dont share it with sources like the headlights as those are known to cause a noise. Also you did not mention what kind of soundstream amp, I had an older (10y/o) one that I had in a prior vehicle that sounded great and worked flawless (no noise etc) but when I installed it in my Boxster I got a alot of engine noise. Took it out and installed brand new Alpine amps and no noise or issues. Just new technology is my guess. As far as antenna wire adaptors, use any german style ones will work.