I recently installed the M Class 16-MC4.75 on two sets of Boston Acoustics Pro 6.5's and the M Class 16-MC1.1100 on two Boston Acoustics 10 inch subs. The head unit is an Eclipse AVN 726E. I have the gains turned all the way down on the 4.75 amp and I still can't turn the volume on the HU all the way up, without distorting some. I noticed that the amps have a switch that says X1 at one position and X10 on the other position. It is labeled input sens. I have these switches on both amps on X1. If I switch them to X10, the sound is greatly decreased. Do I need to have them on X10, then increase the actual gain on the amps, to increase the sound, or am I going about this wrong?
Head unit supposedly has 5V preamp out......Thanks for any help on this matter 