Mighty Shilling

Whelp, we have a whistle coming thru the radio depending on the revs in the Turbo S...What could cause this? Yes, I'm sure it's through the radio, and yes, I'm sure it's not the turbocharger or anything in that system.

Anyway, What could cause this? voltage regulator? bad ground?
Thanks guys!

Zero10

Sounds like a ground loop. Check the grounds on the radio, and any amplifiers connected to the system.
Also check for any speaker wires that may have been grounded.

Mighty Shilling

Awesome thanks. Yeah, the car has a couple amps, and way too many speakers, so this is gonna be a PITA. but hey, it'll be worth it...

Chris_924s

DONT FORGET THE FRIGGING GROUNDS. Resistor wires are the schnizzitt, but bad grounds cause excessive resistance in the circuit and will cause static. listen the the RPM'S, if the signal to noise ratio is too high check the grounds..

Thank you Sid Viscous.. wherever you are.

Zero10

Hmm, if it has a couple amps, then when they were installed, they may have run the grounds from one amp to the next. Try grounding each amp to the same point. The aforementioned method can induce a small difference in the electrical potential at the ground terminal on the amp. This small difference can fluctuate slightly, as the alternator produces a pulsed current (although it's pretty well regulated), these fluctuations cause the electrical potential at the grounding point to vary, especially in relation to the ground at the deck (which is also grounded through the shell of the RCA plugs), which can induce a whine on the output side of the amp. I'm not 100% sure on how that last step happens, as I'm not that deep into electrical/electronic engineering, and all of that transistor logic makes my head hurt =)

So, long story short, ground all of the amps seperately (a common ground point should be alright, just don't chain the ground wire), and check all other relevant grounds.