Thanks, transmaniacon and andzieglj01. I checked the SB-12 NSD, and it looks it is being replaced by the new SB-2000, and is in the same price neighborhood. I found little information on Mordaunt Short Aviano 7; will read some more.
Meanwhile, I did some more measuring and thinking. STF-2 and VTF-1 will be too large for my room. Size-wise, these SVS cubes look really attractive.
Since I have never has a real sub, I decided to educate myself first a bit. On my way home from work I stopped at Magnolia Audio store, and asked if they can recommend something compact and musical. The salesperson recommended REL. He turned on the T-Zero first. It has a 6.5 inch driver. Strong sound, but a bit too forceful. I could tell that the sub is trying to make its way through, and it wasn't blending well with the Martin Logan Motion 15 bookshelves I asked him to play it with. Next, he switched to the REL T-7. The sound was much more refined, gentle and fluid, and I could not really pinpoint the sub's position. I guess this is what I should be looking for? Anyway, I liked it a lot. The REL T-7 has an 8 inch driver on the bottom and a 10-inch radiator on the front. In the store, I didn't realize it is a radiator, and in fact I had to look up the definition once I read the specs. The T-7's size is very agreeable, too. Just a tad over 14 inch, right between the SB-1000 and SB-2000. At $999, though, it is more than what I think of as a reasonable price for my situation. I asked him to switch to the Martin Logan Dynamo 700. In comparison to the REL's T-7, the Dynamo sounded really bad. It is all relative, of course, and perhaps it was not tuned properly, but to me it was clear which one I liked better.
I am sharing this, as I am more and more leaning toward a sealed SVS based on their size and great reviews, and would like to ask if someone has heard the REL subs and whether SVS SB-1000 or SB-2000 can compare to the T-7 in terms of musicality.
Edited by stgatev - 2/3/14 at 11:21pm