"3.4.5 Individual Level Calibration
There are typically two types of pink noise available for speaker/channel calibration:
pink and filtered. For setting relative levels, filtered noise is recommended, as any
room anomalies will not be factored into the level calibration process. For spectral
balance of each channel, pink noise is used with an RTA to adjust the system for
proper frequency response."
Here's another one: I quote from Dolby's DP562 User's Manual (
http://www.dolby.com/products/DP562/562_3.pdf) page 26
"There are two settings for test noise in the DP562: “PINK” or “FILTERED.” If no bass
redirection is chosen (“NONE” - default), calibration of the monitoring system should be made
using the “PINK” test noise option. This option uses a full-band pink noise signal.
If a Bass Redirection option other than “NONE” is selected, calibration of your monitoring
system should be made using the “FILTERED” test noise option. This will compensate for the
absence of low frequencies in your main monitoring speakers. These selections can be performed
in the Setup menu. See Section 5.10 for complete instructions."