ill do my best to type this all out and make sense of my mess.

i just bought my player and am installing it into a center console. i already have a eclipse deck that i wanted to run it through, using its aux. the eclipse is too old and doesnt have that option so i tryed a whole mess of "y" connectors . after i had all of that worked out and started it up i got a terable buzzing noise. it was shooting a 50 hertz note into the subs and the mids and highs both had different tones coming out of them. after i couldnt take the buzzing anymore i took the connections off the back of the empeg. i drove by my local car audio store and asked a few questions . they seemd to think i was getting feedback through the rca's. so i started looking at pre amp eq's with aux switches. after getting one of those and installing everything again i still had the same buzzing. so in this situation i should have absolutaly no way to have feedback through the rca's. then i tryed unplugging the rca's from the eclipse and just running the empeg.
WORKS BEUATIFULY
so basically as long as i have only one deck hooked up, doesnt matter wich, everythings honky doory. when iether or is hooked back up it starts with the buzzing again...
im at a loss. every1 i know is dumbfounded.
i even went as far as to give them there own grounds, power and memory wires. they almost are compleatly separated from each other.
anyway, any help or advise you could give would be gladly appreciated.
thanks

ground islolation transformers and switches...

I agree with Alan. You could put in ground isolating transformers or switches to separate the units. To test if it's a ground loop, try connecting [u]only[/u] the signal (center pin) of the RCAs to the Y cables and to the amp. This isn't a permanent fix but may point you in the right direction.

well, to add more confusion to my mess...after all the ways i hooked them up, running the eclipse through the aux of the empeg worked...its not exactly what i wanted to do but it works...kinda makes the expensive eclipse deck pointless.

But if it runs through the aux of the empeg and it was a ground loop i would still have the noise correct?

ive had alternator noise and al those other spark plug type noises befor...this doesnt seem like a grounding problem. the noise im getting is too loud and is coming out even when the car isnt on.

Please read the notes on ground loops and noise in the FAQ at www.riocar.org under "Car installation questions."

Jeez, people, I go away for the weekend and you're not keeping up with linking the FAQ for me.

yea , been there done that. thats why i tried complealty separate grounds. and like i said...since i have it plugged in the aux of the empeg and i have no noise anymore , doesnt that rule out the loop aka alternator noise or whatever you feel like calling it?

No, it doesn't rule anything out. The problem you described sounds like a ground loop, I don't know what else it could have been.

i guess im at a loss then...
ive had countles systems in my cars and have heard numerious ground loop noises out there. but the sound im getting i just cant see being a grounding problem.
and the worst part is it likes my 6 15"ns right behind my head.
o well... im getting used to having the empeg hooked up as the primary deck already anyway.
thanks