When you get that drastic drop, is it a brief dip or is it an extended step down to a different (lower) level? If your crossover in the receiver or processor is at 80Hz and you haven't got the system and subwoofer/SMS-1 volume levels equal, you will see a sudden and rapid change in level at the crossover point. Check out pages 16 and 17 of Outlaw's SMS-1 guide ( click here to download ) for a guide to help you get the volume levels equal between the sub and the rest of the system.