I have recently been messing around with my RS SPL meter and placement of my Paradigm PW-2200 subwoofer. Well, I finally found the best placement in the rear corner of my 17X12X8 room. Now, when calibrating my sub to 80 hz, and using the corrected RS meter values, I'm +/- 5 db across the entire spectrum with 2 exceptions. First of all, I have an 11 db spike at 30 hz. That seems pretty normal. Now, here's the weird part...I'm getting a 10 db spike at 18 hz (90 db's)and the fact that I'm still hitting 82 db's at least down to 14 hz using the corrected values is puzzling me too (I haven't made tones any lower yet)! Is this possible, or am I doing something wrong? I'm scared to generate any more test tones any lower. I'm afraid I might actually be hitting 10 hz or something! hehe Thanks! David Smith PS I used a freeware tone generating software called NCH tone generator and just burned the files to a cd to play on my system.