I've read DOSBox's wiki article about its mixer to set up the CD audio volume (I find Redneck Rampage's soundtrack way too loud compared to SFX) but it got me stumped.

MIXER channel left:right [/NOSHOW] [/LISTMIDI] […]
Show full quote

MIXER channel left:right [/NOSHOW] [/LISTMIDI]

Channel can be one of the following:
MASTER
DISNEY
SPKR
GUS
SB
FM
[, CDAUDIO]
CDAUDIO is only available if a CD-ROM interface with volume control is enabled (CD image, ioctl_dx).

What am I supposed to put in place of the [, CDAUDIO] parameter ?