I use it to bi-amp my front stereo speakers plus manage the subwoofer. This includes providing the required crossovers as well as notch filters to address cone breakup of my dynamic drivers and filters for dipole equalization of my electrostatic panels. I also use it to time/phase align each driver and I do the parametric EQ of my sub with it also.Good advice!
The DCX seems to have what I need in a single device: 3 separate channels with parametric and dynamic filters.
According to the manual, It should be possible to control signal to the sub and the mains.
Do you use the DCX this way and is it possible to apply REW corrections on this device?
REW works fine in the "Generic EQ" mode but doesn't download the filter values into the DCX if that is what you mean. The DCX has a PC based GUI so entering the REW filter values is straightforward.
Having said all that, it's not clear to me what you are actually trying to do. If it is just EQ'ing your sub then the 1124 is good enough and much cheaper. What do you intend to do with your mains?