This should be the case. You can probably find performances that do localize well. My experience is that this is not generally true. I have played in large bands and orchestras (flute, BTW), and I now play in a recorder consort. Localization WITHIN the ensemble is not good. Music stands, risers, you name it. The whole acoustic environment is dirty. If the performers are lined up is a single line at the front of the stage, localization should be good. Not the normal arrangement for an acoustic group, though. Sorry for rambling, but.... Within an acoustic group, it is important that all of the musicians hear each other. This leads to a semi-circular seating arrangement. I did a church performance recently where our recorder consort was lined up across the stage. I was playing bass recorder at one end and I could not hear the soprano at the other end. The performance was terrible. Finally (I promise), It is getting increasingly difficult to find unamplified performances. Even the Met opera is now amplified.

>>Based on the above discussion, perhaps imaging is good to create the illusion of a live umaplified performance, even if it were not really that way. That's probably one of the reasons why so many folk like single driverspeakers that image so much better (beaming etc) when listening to small arrangements (like one singer and 4-5 instruments).

Certainly. As you said in your original post, creating an illusion is everything. I will take exception to the the statement that "we" like single driver speakers because of the imaging. IMO, the draw of single driver speakers is the lack of cross-over phasing problems in the 300-3000 Hz range where our ears are most sensitive to phasing. With the phase rotation in the cross-over region, our poor little brains become confused and don't properly reproduce the sound stage. This is why a single driver speaker is clearer and has more "life". IMO-YMMV

>>Keeping the room treatment constant, it makes intuitivie sense that speakers with higher directivity will image better. What do you & Wayne think?

Exactly. A highly directive speaker will image even in a poor room. Of course, nothing is free. The sweet spot may only be an inch wide.

Bob