To set the amps gain without any equipment check out the Rockford Fosgate method:
ADJ USTING GAIN
To adjust the gain setting,turn the amplifier gains all the way down (counter-clockwise).Turn
the source unit volume up until distortion is audible and then turn it down a bit until the
distortion is inaudible.This will be about all the way up on most source units.Next,increase the amplifier gain
setting until adequate volume is achieved.
should i turn the loud off too ?
what the LPF freq. should be ??