Just finished installing a pair of Rev10's with the SYN4 amp which is run through the WS420.
Input Mode Switch: Bridge (R IN)
Cross Over Settings: 110, switch set on high
Bass Boost 0
Source Select: 2ch
After connecting everything I am getting a hissing noise from rev 10's when nothing is playing. When play a song cant hear the hiss because music is most likely covering it up and music sounds good.
Gain was set about half way. If turn the gain all the way down still hear slight hiss. Louder as gain goes up. Also if you adjust the frequencies on the ws420 then hiss gets louder as highs are turned clockwise.
I switched the RCA's with in boat speakers amp RCA's and get same results. I switched in boat inputs and tower inputs on ws420 and still get hiss from Rev10's. No hiss from in boat speakers regardless of RCA's used or input used on ws420.
The tower amp and in boat amps are run to a distribution block and don't have separate runs to battery