Originally Posted by ctuna
If the Head Unit is putting out a diff signal with a typical RCA that would mean one of the signal pair is running on the shield . It the shields should touch in a cable bundle that would mean the outside signals are shorted to each other.
Is there a different kind of RCA for differential signals? How do the amp
manufacturers handle this?
If the first proposition is true and there is anyplace where jumped RCA's can touch then it looks like you should put some tape or some kind of insulator around them.
Amp manufacturer's really don't handle it, but if you use a twisted-pair RCA with plastic barrels, it's not an issue. If you use coaxial, or if you use metal barrel RCAs which are touching each other or metal some other way, it can be a problem. Usually that problem manifests itself as RPM-related whine.