Where you place your subs depends a lot on their design and the design of your mains, as well as your reasons for using them in the first place. Consider where they are crossed over to the main speakers, the crossovers slopes, as well as room acoustics. If the crossover point is high and the roll off is shallow the subs will have a lot of audible stereo info and if not placed close to the main speakers will screw with your stereo imaging.
If you plan to run your mains full range and they go fairly low, like 40to50hz, and you have a low cross over point on your sub you may be able to place them most anywhere that adequately provides the additional bass reinforcement you are looking for. If your cross over is low and the slope is very steep you have more flexibility.
Personally, I'm sort of fussy about good stereo imaging so if I were to use subs I would always have them as close to the main speakers as possible unless there was a bass node or null creating problems in that area that needed to be delt with.
Have fun. Good sub integration can be a PITA.
If you plan to run your mains full range and they go fairly low, like 40to50hz, and you have a low cross over point on your sub you may be able to place them most anywhere that adequately provides the additional bass reinforcement you are looking for. If your cross over is low and the slope is very steep you have more flexibility.
Personally, I'm sort of fussy about good stereo imaging so if I were to use subs I would always have them as close to the main speakers as possible unless there was a bass node or null creating problems in that area that needed to be delt with.
Have fun. Good sub integration can be a PITA.