Battling alternator noise in stereo? Here's your solution!

[parsonsj]

I have finally eliminated alternator noise from my stereo system. My system is very simple: one 2 channel amp, 1 sub (powered via amp bridge), 2 mids and 2 tweeters, with a crossover per side. My head unit is my iPhone. The iPhone works great as a head unit: PAC makes a powered adapter that connects the dock connector to the amp, and a non-powered volume control.

Now I listen to MLB.com for baseball games, Pandora for radio, or XMSirius, or the iPod app, and (best of all) my Navigon app. That's right: I have a working GPS-based navigation system in my Nova. All because of the iPhone as the head unit.

I use a Bluetooth headset for talking on the phone, since my car is so loud at most cruising speeds.

That's the good news. I've had all this working for awhile (the Nav system for a couple weeks), but the bad news is that I have had significant alternator whine.

I tried different cabling techniques, different grounds methods, and different power methods. No luck. Then I tried power filters and ground loop filters, but found them unsatisfactory... the power filters didn't work at all, and the ground loop eliminators all took my mid-range away. I tried different vendor's products, and nothing really worked.

Then I found this:

http://www.davidnavone.com/cart.asp?14&pid=178

It's an isolated power supply. It uses your vehicle's power, and provides a completely separate output power. It's as if your stereo components are being powered by another battery that is not connected to your alternator.

Alternator whine: gone. There isn't even a trace of it anymore. I've been searching for this for a year!

Anyway, I thought I'd share my discovery.



jp