Rowland Synergy question with Subwoofer in System

Guys, I have a Synergy IIi in my system and want to experiment with a subwoofer in a two-channel set up. How do I hook a subwoofer up when using a Synergy IIi? Currently I have the main out running balanced R and L to my Rowland 302 amp. I have another output, the Rec Out L and R. But my understanding is that this is different than Pre Out's in that I couldn't control subwoofer volume with the preamp via Rec Out. If true, that doesn't sound so good. Thanks in advance for any suggestions or instructions on subwoofer hook up with the Synergy IIi for two channel listening.
Ok, I feel stupid. I just realized I have a second set of main outs. I'm guessing this is what most use for hooking up a sub to the Synergy IIi.
Unless the second set of mains have a volume control independent from the first set you still won't get what you want. If that is the case you can still use your second set of mains and buy a sub that has it's own remote volume control. There are many out there. I use a Velodyne DD10 which has DSP and room equalization too. My pre, a McIntosh C45 has a sub out and combines all the available low frequencies from all channels and is still completely analog. I need only the McIntosh remote because pushing the TRIM button and the up/down allows quick and easy volume control for the sub. This is not a P match between Mc and Rowland (which is superb). I mention this because the Mc C45 is the only analog pre I know of with this feature.