NHT 3.3 with SA3 Amps????

I have been driving a pair of NHT 3.3 with a pair of NHT SA3 amps on the subs and a 5 channel amp on the upper speakers and center , rears. I just purchased a Proceed Processor, it only has one sub output.
I have two options;
1. Use an RCA splitter on the sub output
2. Use the built in x-overs in the SA3 Amps

Is the Proceed a discrete digital audio processor such as Dolby Digital? If so, do use the Proceed's sub output. If not, use the built in cross overs on the amps.
If it is the AVP it can support dual subs with the latest software.
Thanks, I'm trying to locate the software upgrade website... do you have it?
RCA splitter and let the processor do the crossover at 100hz if I remember correctly. I used an EAD Signature with my NHT 3.3's with a monosub signal. Bi-amping those speakers really wakes them up. Using an EAD Powermaster 2000 with 500watts to the top and bottom on each side is really impressive.