Room EQ

Sarcher30- Try one of the TacT Audio systems(with a MauiMods power supply). If you are not opposed to actively bi-amping: the RCS 2.2's are transparent enough not to lose a bit of ambience, timbre, soundstaging(width/depth) or image information, while providing a beautifully clean mid/high response. I own a DEQ 2496 to test/verify my steady-state freq. response. You can't beat the price for a 6th octave RTA. It's never IN the system though, for the same reasons you've stated.

Shadorne: Are you using the E-mu 0404 USB recording interface or the E-mu 0404 USB Audio/MIDI inerfact. I believe they both have microphone amps, but different output capabilities.

I'm using E-Mu 0404 USB. It is nothing special - although it does have 24 bit capability - but honestly you really don't need anything special for in room bass measurements and the ECM8000 microphone is good enough. I am not sure is if the room EQ wizard allows averaging but a useful feature of Fuzzmeasure is the long 10 second sweeps which you can also average as many times as you want. If you want to get accurate RT60 measurements down to 20 Hz then you need a quiet room to begin (all AC's, furnaces, dishwashers, laundry off and nobody moving around the house) AND you'll likely need to do some averaging (noise level goes down as the square root of the number of repeated measurements and remember that RT60 is the time to decay to -60 db SPL and that is very very low when dealing with bass frequencies that tend to hang around as well as pass through walls).

Remember that your analysis plots cannot see below the noise floor - although our evolutionary honed ears/brain can usually pick out harmonic structures about 15 to 30 db below the same noise floor.