Sorry for the crude drawing. I just threw this together in MSpaint.
I have a small theater build going, and I am going to be placing 2 subs in the room. I ran wires to "X" for one of them, where would you guys suggest for #2, position "Y" or maybe "Z". Or someplace else. I can always move things around a bit once its installed, but i need to run wires this week.
I'd run a wire to each of the three positions, and once the room is built and the subs are in, try various combinations of locations and go with the two locations that work best.
That was my immediate thought too. Plus if you end up buying a 3rd sub down the line, it's already wired for it. Based on my recent experience spending an entire Saturday running wires through my attic crawlspace, and considering how cheap you can buy cables, I'd definitely go that route.
As long as you buy long enough cables to move the subs around and don't mind having visible cables running along the floor, outputting them in the center front and back isn't a bad idea either.
There is actually a lot of science to sub placement.
In a rectangular room with similarly built walls you can pretty much use a room mode calculator to work out where the modal peaks and dips are going to be in the room and use this to inform sub placement. I like to put two subs at the 25% and 75% of width positions in the room. That gives very even bass across one row of seats by putting the subs in the null for the 2nd axial width mode and by canceling most of the 1st and 3rd room modes.
The proper way to do it in a non-rectangular room is to build a model of the room using boundary element or computational fluid dynamics software. That will be accurate enough to show you if your seat to seat variability is low. If your seat to seat variability is low then you can use EQ to deal with the rest.
For example...1 sub
2 subs, carefully placed but still off center in a room
Real life...if you do it right
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