so, i have a head unit with 3 pairs of rca putting out 2V. pioneer 5850. a few guys swear by other units with 6V preamp outs.... but i havent heard a good reason for that can anybody explain why the higher voltage is supposed to be better? also, i´ve been offered a used rockford fosgate (RFX 9220) headunit for a good price. 3 pairs of rca with 5V outs... worth the change over my almost new pioneer? thanks!