Ground loop problem

**Mattkins99** · 04-18-2005, 11:23 AM

I've just been hacking my system together in the last couple of days in order to have a computer for the trip to Bimmerfest next weekend. I'm almost positive the ground loop problem isn't coming from my audio system. The grounds are VERY good an all in one spot. I can disconnect the audio from my laptop (temporary) and the whine goes away. But as soon as it's connected it's there. it doesn't matter if I have the laptop running off the battery or off the AC converter. How can a ground loop come from an isolated battery powered laptop?

Anything anyone can suggest I try? I leave for Bimmerfest in two days early in the morning. That means I only have tonight and tomorrow night to get this fixed. Please help.

**Mattlocked** · 04-18-2005, 12:21 PM

Hi... I'm facing the same problem... whether running on the laptop's battery or DC/DC power supply, and everything grounded to one spot... the humming noise seems to be there to stay... There's also a loud Whine which eventually causes feedback noise when accelerating while the volume is the up.

I've tried a Ground loop isolator from Straight-in but it blocked all audio to my connects2 interface... so it was worse the remedy than the disease...

Hope someone may finally show up with some kind of solution for this Issue, I'm starting to lose my never

**Mattkins99** · 04-18-2005, 01:00 PM

ya, ground loop isolators are really just a patch. I have one in my other car I might rip out just to see what happens.

I lied, my entire audio system isn't grouned to one spot. The Capicator isn't and the factory deck which is plugged into the Aux input of my EQ aren't. I'm going to disconnect the factory deck and then reground the Capicator (can't put it to the same point as everything else without a really long ground though) Which is more important though... having a short ground, or having everything grounded to one point?

I also posted this problem in the Power supply forum for anybody interested
-Matt

**Dave_Perth** · 04-24-2005, 12:05 AM

do you have long RCA's running down the car or near power wires? perhaps its the RCA's picking up the noise. or maybe its just not a very good sound card in the laptop. imusing a laptop and had some MAJOR noise. soon as i switched over the using the soundblaster ZS notebook (PCMCIA) ALLL of the noise was gone

**electron** · 04-24-2005, 12:11 AM

I just installed my CD adapter, and can hear a whining noise which gets louder the more I acccelerate, I assume this is the problem you are discussing? I ran long RCA cables, but used the passenger side since it doesn't have as many power wires, is there anything one can do to 'shield' these RCA wires (besides running 2 RG6 cables)?