Today I tested the in-room bass frequency response of my system. I used: 1. Stereophile's Test CD #3, Track 17 (bass warble tones) 2. Sony 222 SACD/CD player 3. Denon 3803 receiver 4. Polk LSi15 front left/right speakers 5. Radio Shack analog SPL meter I played the test CD through the front left and right speakers only. The speakers are 4' out from the wall and 8' apart. The SPL meter was set to C-weighting/slow response and mounted on a tripod at the listening position, pointed forward and angled up. I set the receiver's volume so that the 200Hz tone from the Stereophile CD was showing 75db on the meter. Anyway, the readings for the bass tones were as follows (I normalized the 200Hz reading to 0 for reference): 200Hz.....0 160Hz.....+0.5 125Hz.....+1 100Hz.....-7.5 (!) 80Hz......-9.5 (!) 63Hz......-1.5 50Hz......+0.5 40Hz......0 31.5Hz....-8.5 (OK, we're below Polk's lower limit) So there's a huge dip in the 80-100Hz area. Thing is, I was standing several feet to the side of the meter and both the 80Hz and 100Hz tones sounded pretty much as loud as the other ones. I decided to move the meter away from the listening position and while I was moving it I saw the needle start to climb. When the meter was 4 feet to the right (or left) of the listening position the levels for both 80Hz and 100Hz were in line with the other frequencies. There's obviously huge cancelation going on at the listening position for certain frequencies. But how representative are stereo "warble" tones of typical source material? Obviously, if the sound were coming from one speaker and not the other there would be no cancelation. Also, this seems to argue for setting the front speakers to "small" and letting a single subwoofer handle the lower bass (or even 2 subwoofers since subwoofers can be moved around pretty freely until the ideal spot is found). This is probably familiar ground to old timers but I'd appreciate hearing any comments. Thanks! PS I don't use the "sub out" channel; I have an old Velodyne which I drive from the Denon's preamp L/R outs. I set its low pass to 40Hz and it blends pretty well with the Polks. I'd hate to have to use the LSi15s as "small" speakers, and my sub doesn't have an unfiltered input so it wouldn't be happy attached to the sub channel.