Peter, The Mackie CFX allows me to stay in stereo or mono with allocation buttons..The main mix ,left and right are controlled by sub out sliders[left and right..being sub out 1 and 2]..This volume is controlled by the master volume..
My sub woofer is controlled by another sub out directly to the sub woofer[my sub out fader #4] is used to control the volume independently from the master fader..

You are correct I have seperate control of the 12's[individually,sub out 1 and 2]overall with master fader..and the Sub woofer with Sub out #4 directly to the powered Sub woofer.

BTW..the Mackie also allows me to feed two seperate monitor mixes[each channel independently] ..Tape out to a recorder, and Unity outs to a house system or another external sound system..
My set up also allows me another send via subout#3 to another sound system..
This Mackie is the most flexable mixer I have owned[including decent effects[32bit]]..

[This message has been edited by Fran Carango (edited 09-04-2005).]