I'm using REW and a BFD DSP1124P for the first time. When I set the levels to do the measurements, I have to put my PB13-U gain down to 7 o'clock and the sweep level down to -17 to acheive 75db on my RS SPL meter. The meter is set to C weighting and slow response. My laptop has input and output line jacks so I'm using the internal Realtek soundcard. I have the REW test tone output through the headphone jack into the BFD, bypassing the AVR. The RS meter is input to the laptop line in jack. I did calibrate the soundcard. The measurements produce normal frequency charts and the applied filters flatten the results out. But I have to crank the gain on the sub to 12 o'clock to get any resonable amount of bass. The trim level for the sub is set at -6 to keep the input level to the BFD from clipping at the levels I listen at. It appears to me the levels for taking measurements are low and I'm not sure if I'm doing something wrong or if they're fine like that.