Another thing to try: Place one sub where you set in your prime listening postition and disconnect the other one. Then, play a repetitive track and walk around the rest of your room. Where the bass sounds the best to you is where you should place the sub. If you want to do even better, use an SPL meter and a Rives audio test disc and walk around the room and measure the response at different locations. Repeat the above process with the second sub. I use two subs and this has been the best way I have found to balance multiple subs in a room.