mlenox

Shortly after purchasing my 2007 997.1, I decided to upgrade the sound and navigation system. I went to our local mega-electronics store, ABT. ABT has an extensive auto stereo section, along with a myriad of other products.
I had the following installed in the 997:

Kenwood eXcelon Double DIN DVD Bluetooth Navigation Receiver

Focal Digital Power Class D 6-Channel Amplifier

Audiofrog GS Series 6" Midrange Car Speaker

Audiofrog GS Series 4" Midrange Car Speaker

Audiofrog GS Series 1" Silk Dome Car Audio Tweeter

After the installation a whine tied to the engine revs became quite noticeable.

I took the car into the installation shop at least three times to see if the whine could be eliminated, to little effect. They replaced wires, tried a high-pass filter, etc.

In addition, the amplifier developed distortion in one of the channels and had to be replaced. During the replacement the tech blew the tweeters, so those, too needed replacement. Everything was covered under warranty, and the whine still remains.

I believe that the common issue of poor amplifier grounding has been addressed as it looks well grounded.

Not sure if amplifier placement plays a role as the amplifier is located at the front wall of the trunk, mounted vertically, near the battery compartment. I tould think that this would improve the issue however.

Has anyone else had this problem or can someone suggest a good stereo shop that can properly diagnose and correct this issue?

Thanks for reading!

FearTheAardvark

I had a similar issue when attempting to add bluetooth integration to the existing OEM system (2007 4s). I had the car back in a half dozen times trying to get the stereo place to diagnose the buzzing before I finally had them take it out and refund me.

Well, fast forward about six months I started to have other electrical issues, it turns out my car was running way under voltage and the whole electrical box needed to be replaced. There was a pin that was completely corroded that distributes charge to the box. It was never confirmed, but I strongly suspect that was responsible. I proceeded to do a self install of a Dension unit after the electrical gremlins were banished and it's crystal clear now. Maybe take a look into that?

TheBruce

I have limited understanding of stereos, or electricity, for that matter :-) Take what I say with a grain of salt.

After installing a LaPower Bluetooth module mine did the same, but far less pronounced. Its a ground loop in the system likely created by powering my external bluetooth module from a different ground than the PCM itself. I tapped the power in the passenger footwell instead of the PCM power.

I havent confirmed this because I found a much simpler way to eliminate 95% of it by just turning the volume up to max on my iPhone. Your iPhone will remember the volume settings for any external sources. It has separate volume controls for phone calls and music so you need to set each independently. When on a call in your car set the volume to max. Do the same when playing music. This allowed me to turn the PCM volume down which virtually eliminated the noise. I can only faintly hear it at high revs if the PCM is on but I have no music playing.

Thinking of my example with the iPhone volume, my second theory is that your amp is underpowered for your new setup making the issue more pronounced.