alternator noise through high

"Alright so your power wire that runs from the battery to the amp and your RCA cable’s run parallel thru the car am I correct?"

My power wires and RCA's run to the amp in the same general direction however they are in close proximity to each other.  Due to the undercarpet heating ducts and other obstacles, they run as close as 18" apart for about two feet.  Due to the same, the speaker wires and individual power wires run together to go back under the carpet. I have no problems with whine thankfully.  How about other noise?  I do hear some good static (pink noise??) when the volume is very low.  Help please.

Factory Honda head unit - Stinger SALOC output converter - Zapco EQ preamp balanced line 8volt output - Zapco Mono amp with pass through to Zapco stereo amp.  Least amount of noise is achievable when:  gains on the output converter are higher and preamp input/output boosts set to 0db, instead of the other way.

Is it a hissing sound that you get?

Yes, it is a hissing sound.

I think it might have been there before, but just not as pronounced now that I have the EQ installed, just put it in Sunday. 

Im just trying to make sure I didnt do anything incorrectly wiring wise.

Hey bberman.  Thanks for the good link.

This article relates to clipping and doesnt address the hissing Im experiencing however, it did give me some other ideas that I could try to minimize the noise.   

I dont compete, so I set up my systems so that there is no way to induce a huge amount of distortion by accident.  I turn all the gains up, and down, so that the head unit's max volume level is just starting to distort.  Though, I may have to do some fine tuning to get rid of that hissing til I get my new head unit. 

Thanks for your help.

Good suggestion bberman1 - I will try disconnecting the converter and see what comes out. 

Interesting... dcash18 - I hope this isnt elementary, but where do I get a CD with a 0 bit track?  Can I burn an 'empty' track?  How?  Never thought about listening to  "          ". 

Alrighty then.  I unplugged the converter and still a hiss.

Deviated from my normal routine and tried re-adjusting all the gains, everywhere.  Tried changing the selectable input voltage on the amps, played with the 0, 6, 12db input and output boosts on the EQ.  I ended up right back where I started with the exception of the EQ volume and Amp volumes at 3/4 full vice all the way full.  Hiss has almost gone!  Gimme a break.  I spent half an hour trying those different combinations.  I was getting EQ hiss from full volume and Amp hiss from full volume.  Just tweaking those two did the trick.   

Interesting note - while I was tuning, I noticed the hiss would go away between tracks.