Hello - I'm getting ready in the next few days to measure my HT room with REQW. I currently have temporary use of a B&K model 2230 SLM with B&K 4155 mic & preamp that has been ISO calibrated and certified. Basically it is flat from 20Hz to 2K. I'm assuming a cal. file is not needed, but need opinions? Also, the B&K SLM has a 2.5VAC output. Does this sound compatible? I will be using a laptop with a Creative Audigy NX 24bit USB card. I plan on reading all the help files for REQW before I start. Any help is appreciated!