Setting up a swarm

They do. To whatever extent they put out bass they are serving as separated bass source locations. The whole idea is to have moe low frequency location sources.

This applies to all speakers. There was a guy last year asking what is the best way to use his four speakers? Stack them with teeters close together?

I said take one pair, disconnect the tweeter or put a pillow over it, and put them down on the floor facing the wall. They need to be facing the wall because without a proper sub crossover they will put out high frequencies that can be localized, and we don't want that. We just want the bass.

Well much to my surprise he tried it, and was real impressed. The best bass he ever heard from those speakers, including running them all together. So this totally works. Even without a sub. It's that good.

Yes the drivers face the wall. About 2" away. Not that it is all that big a deal. Bass waves are so long direction hardly matters. What does matter though is they look better that way! Honestly, that is the reason!  

Powered subs are no different. Sound doesn't care if the amp is on the floor or on a plate inside the sub. Only difference is how you hook it up and make adjustments. Four of mine are passive, powered off Dayton SA-1000 amps. The fifth is a powered Talon Roc. 

And yeah I respond to PM's. All the time. Heh.