I am building new desk top speakers and they will die at 60hz. I'd like to do multiple subs and looking for an existing project that uses 4 small cube subs, maybe 6" drivers each, so I can get some smoothing.
For best results in an enclosed space, room, use one sub. That will stop the phasing effect of no bass in certain places in the room caused by reflections. Not so noticeable with higher frequencies.