05-07-2013, 04:48 PM
Sounds like channels 3&4 is set to low pass filter (to power a sub). There should be a switch for each channel with HPF/Off/LPF, stick it in the middle.
If you've tried different RCAs for channel 2 it sounds like there may be something wrong with that output.
If you've tried different RCAs for channel 2 it sounds like there may be something wrong with that output.