I just realized I posted this in Hardware rather than the Coffee House. My apologies to the hardware nerds. Although this forum does attract a better class of clientele. (Bapu? Is that you peeking around the bouncer at the door? Kitchen entrance is in the back, bub.)
bats, that's a good suggestion. Dregs will be in rotation today. I'm trying to listen to every world-class recording I have, from every genre and decade. That alone has been an interesting experience. Some records just sound good no matter where you play them - Dream Theater's "Pull Me Under" has never sounded bad anywhere. Anything out of Nashville is a pretty good test, too, whether it's pop, current or classic country or bluegrass. That Nashville sound is perfect for calibrating one's monitoring system.
Part of my setup involved tweaking my room EQ. I use an external hardware equalizer for that rather than software (hey, there's the Hardware connection!). It's a cheap equalizer (I paid, IIRC, $150 for it new), a Behringer FBQ2496 (now discontinued, I think).
It's marketed as an automatic anti-feedback controller for live sound, but I've never even tried using it that way. In manual mode, it features 20 independent parametric filters. What I do is start with a SONAR test project with white noise, stepped sinewaves and some reference songs, and tweak a software EQ for the flattest response. I write down the filter frequency, Q and gain settings and then transfer them to the FBQ as my starting point.
Next, I set an omnidirectional microphone in the listening positing at ear level and turn on input monitoring. Two instances of SPAN, one showing the spectrum of the test signal/song, the other showing what the microphone is hearing, allow me to compare what's coming out of the speakers versus what's in the source. Doing this prevents me from making adjustments that just sound good, versus adjustments that improve accuracy.