Audiophile equipment is new to me, though old(er).
For the last few years I'v been trying various speakers: Some can benefit from a sub, I believe. Currently I own Tylers Mini, Rain Makers, Silverline SR11&&17, ERA D4 and most recently a pair of Triangle 202, which I like alot.
Yes, I'm infected and probably need help. I'm therapist, which is of zero help, of course...save the humour.

I presently use an inexpensive Yamaha sub. My room is 10x12, 10 ft ceilings. Power is Harmon Kardon 3470 or NAD 7175 PE. Any suggestion for an all around good sub with flexibility for the various speakers and those to come?

Thanks in advance. Cheers.
That room will never be right for bass. It's lousy advice, I know, but... change the room. There's a limit to how much you can fight the physics.
My room is 10X13X8 and the bass is wonderful. I've had several people comment on how clean and articulate the bass is.
Drew, that's odd, when I tried the "learning" subs (velodyne specifically) when I had a system in a very small room in the basement my experience was that sure some manipulation could affect performance in specific areas (frequencies), but the sub just wasn't very good.

Applying filtration to a sub that just doesn't produce a strongly musical sound performance and the ability to stay caught up with my speakers (at the time a pair of Wilson Audio Duettes) didn't do it for me.

All the digital manipulation didn't make up for a somewhat lacking sub in the first place.

My recommendation is to find a sub that has high performance characteristics and good speed, whether with or without all the digital filtration/adulteration components built-in.

A finely tuned Yugo is still a Yugo and no matter how good of a condition its engine is in, it's performance will always be limited.
I agree with Drew.

The best bet that I could point to is either the Velodyne SMS-1 sub-controller (app $400, I use one in my system) or the SVS Audyssey Box (app $800 plus the cost of the required external active cross-over). The specific choice of subwoofer (while important) is -IMHO- less critical in a small room than the use of room correction.

I will disagre with Drew's "auto calibrate" advice - for the most part. The Velo automatic option sucks, it is primitive and doesn't even scratch the surface of what the SMS can do. In fact, all of the auto-calibate systems that I've heard come up short of manual calibration (although they are way better than no correction at all).
IME, manual correction - while a major PITA -is still the best way to go. Disclaimer: there may be good auto-calibrate systems out there which I haven't heard.

As to the sub choice, I use 12" Rythmiks. Very good sounding, very flexible (adjustible Q), and reasonably priced.

Good Luck,

IMO ,your getting bad advise outside moving the system to another space.I doubt a room 10-13 room has"wonderful bass"as stated(unless youve never heard a really great system then maybe).To suggest a sub choice for a 10-12 room is quite comical as your basically listening nearfield,again My opinion.