I am in the process of building a dedicated home theater right now. The room is about 10'x17'x7'. The TV is on the 10' wall. The problem that I have is that I do not have enough room the adequately place a pair of front speaker on the sides of a the TV and still have room to put subs in the corners. I am building two shiva sealed enclosures (down firing). The question that I have is: Can the sub enclosures be mounted in the front upper left and right corners of the room? The enclosures would be mounted so that the drivers fire toward the ceiling. This would be to save floor space and still keep the subs corner loaded. I know that special consideration is needed when designing down firing subs to account for gravity effect on the driver. But what about upwards firing driver?