One or two subs

Guys, thank you for all your responses. Ive decided to go with two Rel T7s. My pre is the yamaha cxa5000, has dual sub outputs but the second output saids for rear sub, should i just plug into that or get a RCA splitter, thanks and will update once i set everything up.

See "SWFR Layout" settings, page 108 in the owners manual.

I'm going to ALWAYS advise against some recommended loudspeaker location recommendation layout in an owners manual, as there's simply too many unacounted for variables to consider for best results. Each layout and seating situation is different. Bottom line is loudspeaker / subwoofer placement in the room for any given room layout and seating locations, acoustics, etc, is going to vary greatly. And while some owners manual or recommended setup in a book can give you a rough idea, you still need to find the main seating location, and set speakers and subs according to those first, and then plot other seating after that. Then measure and listen for all, and maybe make tweaks and adjustments.
Never follow some random piece of literatures setup instructions for your space! Your ears are final judge - but measurements will always need to fall somewhere near accurate for good sound and performance. -especially when it comes to bass response! EQ the rest...

Hey everyone, just wanted to give you guys an update. Finally got the Rel T7s and started the dial in process. I must say, i couldn't be happier, the balance, soundstage is something i never thought was possible. I would always recommend dual subs for anyone who has the budget. For music i used, Royals by Lorde, Seven Nation Army by White Stripes and for movie used Dark Knight and Frozen.