Although the VSX-48 has no computer interface capability, it is still a very viable Loudspeaker Management DSP.
If you are determined to have a unit that can be controlled transparently in real time, you owe it to yourself to have a look at the Digitool MX
Owners Manual: http://www.peavey.com/media/pdf/aa/80303050.pdf
GUI (Graphic User Interface): http://aa.peavey.com/downloads/software/
Then click on: Download Flash and Utility program version 3.42b
Yes it is more money than the VSX-48, but it is so much more than a X-Over, with 8 Inputs x 8 Outputs it can be a complete system mixer, providing management and more.
Some even run it wirelessly via Bluetooth and other technologies.
I know of one world famous nightclub (Tootsie's in Nashville) that uses one to drive their FOH system, another to Bi-amp their monitors, and a third Digitool just to use the compression capabilities on channels and sub mixes.