Multiple low frequency sources spread around the room either symmetrically or asymmetrically (my preference) will result in smoother in-room bass. This is in part because there is a unique peak-and-dip pattern at the listening position for each subwoofer location, so the sum of multiple subwoofers will average out smoother than any single unequalized sub. This smoothing effect has been demonstrated by several researchers (Welti et al, Geddes).
Duke
dealer/manufacturer
Duke
dealer/manufacturer