I have LS speakers and 2 mono 200w power amp. With these speakers, I can't go above of 9 o'clock with the preamp volume knob. But at this position, subwoofer is too quiet.
If I switch off my 2 power amps, and go to 10 or 11 o'clok with the preamp, the sub works perfectly, but at this volume, I'll become deaf immediatly.
So, the solution I've found is to reduce the signal between the preamp and the power amps, in this way, I'll be able to go up above 11 o'clock with the LS.