I'm having a bit of trouble calibrating my HSU VTF-2 subwoofer with the rest of my system (receiver-Marantz 7300; fronts Polk RTi150; center Polk CSi40; surrounds RTi38; and back CSi30). I've set all speakers to "Small" in the Marantz receiver's set-up menu and set the crossover to 80 Hz. Using a digital spl meter, I've used the Marantz calibration menu to adjust all of the speakers and the subwoofer so they are outputting 75dB when the receiver's volume is set at 0. I've also used the Avia DVD to double check to see that the subwoofer and the front speakers output levels match. Ok, now here is my trouble. First, and this just seems odd, to get the sub to match the other speakers at 75db, I have to turn the volume knob on the VTF-2 to something like 10%-15% of its potential. This doesn't seem right to me, the VTF-2 only has a 10" speaker, and I'm in a 14'x14' room with lots of openings into other rooms. Does this situation sound right? Second, to my ear, the bass isn't strong enough. However, the spl meter is saying the subwoofer is cranking out bass at the same level as the other speakers. Am I doing something wrong?