Hi Folks,
I have been mixing subs-on-an-aux for about fifteen years.
Some folks link the sub-aux-master with the L/R master, but usually I control these separately.
If wanted, on the DL1608 The L/R master and sub-aux-master could be controlled by a single VCA.
I often have delay-fills, and occasionally center-fills, on auxes as well. These ARE linked with the L/R master with a VCA.
Thanks and good health, Weogo