Small or large sub for music

TBC, having the space and money to have 4 subs is not the normal music lover's situation. 

@mapman  was talking to that. He was not discrediting the use of 4 subs. 

I too will never be able to have more than 1 sub in my listening area so to me, the 4 sub array point is moot.

That doesn't mean I don't see the merits. From a cost/performance space situation, the bass traps + eq are the far better and cheaper option, but hey, I make my own loudspeakers so the measurement and calibration is waaay easier for me than the average music lover. 

noble yes for 20 hz in large room you need at least 1 larger sub up to teh task (check specs) or multiple subs or drivers. Distributed multiple subs or sub array allows more  for smoother bass response throughout a room than extending low end frequency response..

Ideally I would want  2-4 larger quality subs distributed around a room but practically I do not want to have to deal with all that so I go with just a single smaller sub that is easier to manage.   This is in a second system.  My main system has full range speakers so no subs needed. 

Why does anybody care if the bass is distributed evenly around the room? Is this so you can enjoy accurate bass while doing your yoga headstand against the wall? Weeping about things in the corner until the housekeeper finds you? I use 2 subs that seem to help cancel some room standing wave issues, but I do serious listening from my specific sweet spot (like most audio geeks) which is where stereo mixes actually work. If anybody wants to really appreciate my rig along with me, it's necessary they sit in my lap or stand behind me while I sit in my "magic" spot. Also, it's possible to get great (and musically rewarding) sound from one sub as this is generally better than no sub at all. Movie sound is the McDonalds of audio...lots of salt and fat to make you feel good initially, but it has very little to do with good food...as a reference for audio, film sound is a ridiculous mix of extremes that isn't really designed for music appreciation. If you spend your time listening to and enjoying the digital reproduction of Army tanks and explosions, you're unique and hat's off to you!

I hardly ever sit in the sweet spot. and I have never been concerned with getting the deepest bass. I can't think of any of my guests wanting to stack up on or behind the sweet spot either, but we all want to hear good sound wherever we are in the room, or house for that matter. Not to mention I disliked having my guests ask me about all the acoustic panels I had and why. They appreciate my art collection that hangs on the wall now much more. Thanks to the 4 box distributed array we can eat, drink and enjoy music. Room size is 14 x 20 so with their small footprint they fit quite nicely and nobody trips over them.