Cdc,
If you must use a broadband noise signal, use pink noise. White noise will be irrelevant. If you use a broadband noise signal like pink noise, you need to have a spectum analyzer to really be able to measure the in room response. These will generaly give you a graphic display with frequency on the x axis, and absolute level on the y axis. Much like the graphs we all see in Stereophile etc. Measurments of this type get tricky and expensive.
Stereophile's discs do miss much of the spectrum, but what they include are tones that actually apply to areas in your listening room that you might actually have realistic control over. They also assume the average listener is going to have a radio shack SPL meter that has poor frequency response in the low and high end.
