bass suggestions 12 x 16 room....

Hopefully, through positioning, you can reduce the problem to a narrow range of bass frequencies (ie. 50Hz-->60Hz) If it still bothers you, it might be necessary to change out the speakers for ones that roll off below about 60 Hz or use a parametric equalizer or low pass filter.

You may need a sound level meter, a tripod and some test tones (on a CD or otherwise) to fix these issues.

My room is 13x15. I stick to sealed box or front ported speakers. Could never get the bottom end under control with anything rear ported. And my room is well damped. Don't have the luxury of putting the speakers 4 feet from the back wall.

Wouldn't hurt to try some bass traps in the corners. Another thought, does your amp have adequate power for the speakers? The rest is all about speaker placement. Good Luck

You need bass trap pure and simple. This is your bottom line need and it will get you what you are looking for period. Buy GIK corner bass traps stacked floor to ceiling in your corners and you will be amazed.

The suggestion for sealed box speakers is a good one, in my experience. I've got a room of similar size, and had good luck with a pair of little Spendors (forget the model), and I'm back to using my beloved Celestion SL-700s. It took about eight months, but I finally got 'em positioned just right. (Long wall, about a foot and a half from the rear of the speaker to the wall.) I tried several ported designs, but couldn't get any of them to work in that room.
Good luck.
-- Howard