Here's my head unit specs:
5v peak/ 2v RMS RCA output on all channels
100 ohm low impedance pre-amp outputs
bass frequency adjustment - 60, 80, 100, 130, 150 and 200hz
bass q factor - 1, 1.25, 1.5, and 2
treble frequency adjustment - 10, 12.5, 15, and 17khz
sub x-over - 80, 120, and 160hz
sub phase - 0 - 180
sub level - variable
5v peak/ 2v RMS RCA output on all channels
100 ohm low impedance pre-amp outputs
bass frequency adjustment - 60, 80, 100, 130, 150 and 200hz
bass q factor - 1, 1.25, 1.5, and 2
treble frequency adjustment - 10, 12.5, 15, and 17khz
sub x-over - 80, 120, and 160hz
sub phase - 0 - 180
sub level - variable