Why "bookshelf" sspeakers?

I believe a more compelling reason is that bookshelves can be arranged in space for improved imaging and soundstage. Additionally, the option to add subwoofers allows for flexible placement to avoid peaks and valleys, ensuring more uniform bass.

@grannyring    Yes, exceptions always exist. The Seawave Acoustic AM 23($20K) might exceed the Totem Element Metal V2($18.5k) but I have not heard a better allrounder for < $20k regardless of speaker size or type. In general the consumer is getting more value/sound for his money with a tower speaker.

There are several points I don't understand:

1. "Bigger floor-mounted boxes may have coloration from cabinet vibrations and resonance which can impact the coherence and detail of the midband."

It seems to me that any poorly designed cabinet can have issues, small or large. For a comparison to matter I think we'd have to compare well designed towers vs well designed bookshelfs.

2. The point keeps getting made that stand mounted speakers and subs are easier to position in a room to optimize room acoustics. Why would this be any different from floorstanders. The Aerial Acoustics 5Ts on heavy stands were no easier to move  or position than the 6T towers. And subs aren't exclusive to stand mount systems so they can be used with towers too.

I'm just playing devil's advocate here. I'm not in the market for speakers and this was just something that puzzled me.

You can only make a small speaker so big, which is to say that a stand-mounted speaker is usually just that: small.

However some larger speakers, albeit mostly pro segment, aren’t shaped like towers - like ATC’s pro, active monitors SCM150 and 300 models - and so need stands. The Meyer Sound X-10’s (big speakers) needed short stands, if not flush mounted in the wall, to be at proper ear level. The S.P. Technology Timepiece speakers I owned +10 years ago were fairly bulky, weighed over 60 pounds per cab and needed taller stands to be lifted to ear level.

Obviously such speakers don’t qualify to be placed in the typical category of stand-mounted speakers, but being there are a range speakers that defy that category as stand-mounted items, why not just call their typical segment for what they are, i.e.: smaller speakers? So, why smaller speakers vs. bigger dittos?

I would say that if you’re high-passing your main speakers - be they small, medium or larger sized - then adding subs makes very good sense to find the better placement both for what the mains are supposed to do best, as well as the subs for their range of reproduction (I mean, you’re hovering on either side of the Schroeder frequency). Not to mention that you’re freeing up the mains from LF-signals, with all that entails of advantages. Ideally you need what’s essentially the same amps top to bottom, including subs, but that’s for another thread..

EDIT: actually, if your mains reach down into the 40Hz range you could experiment with running them full-range, and thus placing subs at a proper, minimum distance would add to the number of bass sources (mains + subs) for an effective DBA and smoother acoustical response. That’s two scenarios (vs. high-passed mains) that could be looked into and compared, and depending on the circumstances I guess could go either way with regard to preference here.