So the story usually goes like this.
Back when tube-based amplification was the only option, and most tube amps were really low powered, designing speakers with high sensitivity was the only way to go--there was simply no alternative if you wanted to reproduce voice or music.
With the advent of transistors, and then ever "cheaper" watts, designers started creating lower sensitivity speakers. Think Thiel, Apogee, and a bunch of others. It's reasonable to assume that they had specific design goals that led them in this direction, and that it wasn't the result of a lack of effort on their part.
The renaissance of tube amplification has seen a similar movement among suitable speakers, so nowadays there are plenty of options for everybody. Of course, it's preposterous to rule out all speakers under a certain sensitivity.
Another major factor here is impedance; speaker sensitivity doesn't exist in some kind of electro-acoustic vacuum. A certain well-known brand makes speakers with 86dB sensitivity but about an average 12 ohm impedance. Go figure.
The long and the short is: find the speaker first that most pleases you, then find the right amp to drive it. This advice has already been repeated many times over on this forum.
Back when tube-based amplification was the only option, and most tube amps were really low powered, designing speakers with high sensitivity was the only way to go--there was simply no alternative if you wanted to reproduce voice or music.
With the advent of transistors, and then ever "cheaper" watts, designers started creating lower sensitivity speakers. Think Thiel, Apogee, and a bunch of others. It's reasonable to assume that they had specific design goals that led them in this direction, and that it wasn't the result of a lack of effort on their part.
The renaissance of tube amplification has seen a similar movement among suitable speakers, so nowadays there are plenty of options for everybody. Of course, it's preposterous to rule out all speakers under a certain sensitivity.
Another major factor here is impedance; speaker sensitivity doesn't exist in some kind of electro-acoustic vacuum. A certain well-known brand makes speakers with 86dB sensitivity but about an average 12 ohm impedance. Go figure.
The long and the short is: find the speaker first that most pleases you, then find the right amp to drive it. This advice has already been repeated many times over on this forum.