16 x 12...ideal sub size

Multiple small subs can also work wonders for mitigating room modes and providing the proper SPL to compliment your mains.

A big sub always has an advantage. The old saying still holds true . . . there's no replacement for displacement . . . and a large driver doesn't have to move much to get that displacement.

My room is 12X19X7 high.
I was using JL F-113's in there and no matter where I put them I couldn't get the bottom end to sound the way I wanted(I have tried everything).
one of my dealers I was talking about this told me after he demoed me a monster of a sub in his 4X the size of mine.
He told me it doesn't matter the size of the room.
I have never heard better bottom end like that in all the rooms I've been in.
Try to make this short,he gave me the demo disc he was using(Jeff Beck Live at Ronnie Scott's)Bluray.
I tried that disc at home with my JL's,it totally sucked,talk a let down.
I phoned him and told me it was probably my small room as his was huge compared to mine.
As stated above it doesn't matter the size of room(HE WAS RIGHT).
He brought the sub over for home demo,we hooked her up and put in Jeff Beck,even before he did any vol setting or anything else as soon as that track started I yelled THAT'S IT.
I couldn't believe it,but I was and am so happy.
The bottom end in my room sounds so superb and mids and highs are so much more free on top.It's very hard to describe the sound but when you hear it you know instantly.
Quality sound up the ying yang.
THe sub he brought over and it is a monster is the discontinued Velodyne 1812.I've never heard such quality for the bottom,almost as if I had a sound engineer in my room with Jeff Beck and I have a front seat.
What this sub does for music and movies the F-113's make solid end tables,there's no comparison.
I now know that room size doesn't matter as was proven to me.
Hopefully your dealer(S) has a few different makes of subs and you can audition them.
I believe you cand do 12's to 18 " in your room.
Subs do take up realestate,but it's the sound I'm after not
cute small boxes that go boom boom.
This 1812 sub is over 300lbs and is 40"Hx25"wX18"D.
Some said she looks like a front loading dryer.
As soon as I demo the disc they are speechless and complain when I only play part of the tracks(LOL).
Ive had some dealers say my JL's were to big for my room.
It was the sound that sucked not the size of them.
I think he just wanted to sell me a couple of his subs.I'd go big as you can if THAT sound is what your after, to hell with looks.
Hope you find the sound your after as I did.

**Dealer disclaimer**

I don't think you are limited to a sub that small. Thats not to say you can't get good results from them though. I would think a good quality sub of 12"-15" would be fine. My main room at home is 16X20, and I use a pair of 12" Velodynes for stereo. I also have an 18" Velo in that room which I add for home theater. The JL's are great too. You didn't mention a budget, but the PSB's are real musical, and a lot less money. If I ever go with new subs, they would be on my short list as well.