Using a Pioneer Headunit in my EX:

According to other postings on the forum, the EX's subwoofer connector uses the red/blue as a positive and the red/white as a negative connector. On an RCA, the pin is considered positive, the shield is considered negative.

So, the wiring should be:
RCA pin -> red/blue
RCA shield -> red/white

However, wired this way to the non-fading outputs of my headunit, the subwoofer would continually shake even with a CD on pause, giving evidence of a probable ground loop of some kind. When I tried reversing this wiring and connecting the RCA *pin* of my sub-out to the red/white and the shield to the red/blue, there was no reverberation at all, and the bass was deeper and much more correct.

A similar situation had occurred with the other four channels when I had the cheap speaker-to-line-level adapters in place, where reversing the wiring mostly mitigated the problem. The real fix for those four channels was using a more expensive converter that had ground loop circuitry (capacitors) integrated into the unit.

Any takers as to what's going on with the sub connection? It works fine now, but I wonder if I'm setting myself up for electrical problems, dead batterys or fire due to the reversal...

Perhaps there's something odd about the headunit? I'd consider putting capacitors inline with the two sub-out wiress, but they're much more likely to cause sound problems down in that frequency range, being high-pass filters, after all...

-brendan