Millercarbon, now you know I use 4 subwoofers but with a smaller system two subs can work fine but two subs is the minimum. I used a two sub system for years until I graduated to line source speakers then two was not enough to match the power projection of the speakers. I did not know the acoustical benefit of multiple subs in terms of minimizing standing waves.
Yeah that's what got my attention in the first place. One sub creates standing waves. Every sub. Every room. Its physics. We know this. The epiphone was to figure out the answer is lots of subs. With more subs in more locations they no longer have to be very big or powerful because there's so many. And being in so many different locations the modes or standing waves they create are all over the place. So instead of a few really big standing waves you get to where they are so small and so many its almost like no standing waves at all. Its just brilliant, creative, genius!
I recently had a guest over and he is one of those guys who has been to a lot of shows and heard a lot of really high end systems and even he was impressed. Which is freaking amazing considering my subs cost about $3k all together and my whole system is probably about the sales tax on a lot of them nowadays. Yet his comment was, " I heard fabulous clarity and fat, full soundstage. I’m not just saying. I heard and felt it!"
Note the "felt it" part. And what he didn't email but did say in person is the bass is totally integrated and at one with the overall presentation. In other words the "fabulous clarity" includes even the deepest bass.
This is because Duke and Geddes, et al, are right. Smooth bass is fast bass and the more subs the smoother it gets.
The physics is the same regardless of the room or the system. The only thing I can see changing if the system or the room gets a lot smaller is the subs won't need to be as big or powerful. But they will need to be many.