My Onkyo 989 has dual pre-outs for the sub. If I get lucky and am able to pick up a 2nd SVS, what benefit, if any would I see by using this? My current setup is: Onkyo sub pre-out1 into BFD1124p left channel (input #1) into Samson input #2 (stereo mode). If there's no benefit to using the 2nd pre-out, I would save some $$ by not having to get more interconnects (Onk to BFD to S700), and could just change the BFD #1 out to S700 input #1, change to parallel mode, and only need some speaker wire for the 2nd SVS. If I use the 2nd pre-out, I'd need an interconnect from the Onk to the BFD, then from the BFD to the S700. However, this would allow me to use the 2nd channel (engine) of the BFD to set up different filters (of the same preset) to control the 2nd sub. Right now I have only one BFD engine running (to cut down on light pollution). I guess another alternative would be to get an RCA to dual 1/4 Y adapter for the receiver to the BFD? Or is there a downside to splitting the one pre-out from the Onk? If I do nothing but just change the S700 input to #1, switch to parallel mode, and connect a 2nd sub, the current filters I'm using on the BFD would apply to both subs, right? And maybe that would work if they are both in the same corner? Help! My brain is full! Is there an optimal setup for the above?