Set up will be the most critical factor for not getting "boom, boom, boom" for you. Bass is the most placement critical factor for speaker placement. The best subs in the world will sound boomy and one-notey, with little definition, and have other challenges or shorcommings without proper set up, placement, and calibration(phase, level, coherence, EQ(?), etc) Get that right and you'll be amazed at the sound quality!!
However, the sub itself being almost half the sound itself(the room, set up, etc, being the rest), you need a good choice for your room size, yes.
My suggestion would be between the M&K MX series subs(probably MX200 or above for your room), or the Earthquake MKIV 12" 580 watt sub!(yeah, it sounds boomy, but it's not). The M&K"s are widely used by pro studio's(including Lucas film THX), they're VERY MUSICAL AND ACCURATE SOUNDING, and are very efficient and quick designs. The Earthquakes have a bit more "growl" to them, but are also tight and musical. Infact, the 15" version was rated Jan 2003's Stereophile Guide to HT's "sub of the year" award!(see review).
I've used a lot of subs over the years, and for the money, for your purposes, you'll not really do much better.
Good luck
However, the sub itself being almost half the sound itself(the room, set up, etc, being the rest), you need a good choice for your room size, yes.
My suggestion would be between the M&K MX series subs(probably MX200 or above for your room), or the Earthquake MKIV 12" 580 watt sub!(yeah, it sounds boomy, but it's not). The M&K"s are widely used by pro studio's(including Lucas film THX), they're VERY MUSICAL AND ACCURATE SOUNDING, and are very efficient and quick designs. The Earthquakes have a bit more "growl" to them, but are also tight and musical. Infact, the 15" version was rated Jan 2003's Stereophile Guide to HT's "sub of the year" award!(see review).
I've used a lot of subs over the years, and for the money, for your purposes, you'll not really do much better.
Good luck