Hope this belongs here and not in setup thread. I have Denon 1603, Paridigm Monitor 7s CC370 and Pw 2200 Sub. Room is 12 by 20. Sub is 3 feet from side wall 18 inches from back wall next to left speaker. Crossover on reciever set to 80 HZ crossover on sub wide open at 150HZ. All speakers set to small. When I run a low frequency sweep with AVIA I get a few little dips and bumps (not too bad) until about 80 HZ then I get a huge dip until about 65 HZ and then back up again.(USING RS sound meter) Have I done something wrong in my setup or could it just be my room. I don't have HUGE choice in placement. I tried a few small changes but the hole is still there. Can anyone help me?