Originally Posted by AV Science Sales 5
The recommendation for a bookshelf over the tower applies when looking at what you get for the same dollar value. You combine that with losing the low end ability of the tower to the sub and I still say there is not a compelling argument to go with towers.
This is correct.
Having a speaker that goes down far past 80hz doesn't matter in a multi-channel system because the speakers, when setup correctly, will never... ever see that from the processor/amp. In-general, signals under 80hz get cutoff and rerouted to the subwoofer. Why? Because bass under 80hz offers no localization, Dolby Labs set the AC3 standard this way to allow for the best subwoofer placement for the room. This yields, in properly set systems, the best sound for a MOVIE sound track. Again, this has NOTHING to do with 2 channel listening and is NOT part of this reasoning or setup.
There is one particular reason (performance wise) to go with larger speakers for HT use and that is if your room is incredibly large and you will need the extra extension to hit reference volumes. Even then, there are some really large "bookshelf" speakers that are designed for maximum output all the way to 80hz in large rooms. Can you run some of those as full range or "large"? Sure. Does it do anything for you? Not unless you are without sub.
Klipsch THX Ultra2 & Atlantic Technology's 8200e systems are designed for large rooms and neither of those are floor standing. Phase Technology dARTS will play reference level sound pressures in incredibly large spaces and that system uses 6 1/2" woofers in very compact speakers. ADAM-Audio has two GTC models that will do high output in largish rooms. PSB has speakers like this as well. Many many companies do.
BG Radia has an in-wall, the SA-360 http://bgcorp.com/PDFs/SA-360%20ProductSheet.pdf
that is not particularly huge at 32" tall. It utilizes 2, 8" woofers for the low end. While you can run these as "large" and use them as 2 channel stereo speakers if desired, this speaker will absolutely crush a HUGE room when crossed over to 80hz. We used this coupled with a Parasound 5250 in a 40' wide x 50' deep open basement behind a 165" screen and it was unreal. Absolutely did NOT flinch at reference at the seating position 20' away. Crystal clear and dynamic without breaking a sweat.
My point is that if you look at most manufacturers theater system offerings, you will not find many floor standing models. In fact, it's quite the opposite: A great many large monitors. Typically, you are going to get a much better system, with higher quality for the $$$$ if you stick with models engineered for high output down to 80hz. One exception to this would be line arrays where a larger wave form is needed to cover multiple rows of seating.
Hope this helps someone!