Is the most efficient speaker the best speaker?

I've read though the post... The op says "All things being equal" no debate on horns vs planars... Two identical horns, playing exact frequency curves, playing exact impedance & phase curves, playing the exact music... Or two exact matching planars or two exact matching dynamic drivers.... ALL THINGS BEING EQUAL, The more sensitive speaker will be more dynamic... The answer is Yes.

...And allow more noise in.

06-24-11: Timlub
I haven't read all of these post, so it might have been answered...The answer to the exact question is yes.... In theory. If all things are totally equal except for sensitivity, the two speakers will sound identical except in the area of dynamics. The more sensitive speaker will be more dynamic. Next... This is impossible
06-24-11: Timlub

Will have to disagree more sensitivity does not mean more dynamics...

regards,

Mapman`s analogy ignores that obvious fact that those portable devices are built to a price point and meant for very affordable(cheap!) entertainment purposes. The truth is within all speaker catagories there exist a hierarchy of performance. Some low efficiency speakers are wonderful and some poor sounding, same with higher efficiency models.

The goods news is there`s room in high end audio for us all. Now on the other hand, tubes vs solid state....

Well, I suppose if we were to take this somewhat academic question literaly, both speakers would be equally dynamic and equally capable of the same level of noise rejection, and equally capable with the same amplification.