Low-sensitivity speakers — What's special about them?

Al was a really nice guy. I miss having him here.

A 86/87dB 1w/1m speaker referred to often as "low sensitivity" is only 3dB away from a 90dB 1w/1m - referred to as a "high sensitivity speaker".

Although most of the post from which I extracted this is good information, this statement really isn't right. A 'high sensitivity speaker' is really going to be more like 96dB at the lowest; there's something called 'medium sensitivity' which is about 90 to 96dB.

What is special is that the crossover is so large with parts and parts that most if not all the music is sucked out....more power ain't going to help.

@atmasphere --

Al was a really nice guy. I miss having him here.

Indeed - a very knowledgeable guy, well-spoken and always with a balanced and to-the-point approach. 

.. A 'high sensitivity speaker' is really going to be more like 96dB at the lowest; there's something called 'medium sensitivity' which is about 90 to 96dB.

Was going to bring this up as well. I guess it's illuminative into the inertia of hi-fi speakers being by and large rather inefficient, and that anything that hits higher at 90dB's or slightly above this number is then deemed "high efficiency." It certainly is not.  

@lonemountain --

The thermal compression you speak of is purely a function of the driver's ability to dissipate heat, not the amplifier, as all voice coils get hot when "powered up" by any size amplifier. Its the inability to cool the driver that causes thermal compression and reduces driver performance.

Definitely, and therefore it also goes to show that compensating for low efficiency by simply adding more wattage will, all things being equal, more easily meet the drivers saturation point in regards to thermal compression. 

Thermal compression happens to high and low sensitivity speakers at all price points.

But at different SPL's, that's the whole point. 

Listeners will wonder why their speakers "sound different" when played loud for periods of time, this is a voice coil heating up and reducing its dynamic range. Since its impossible to see this in action, its within the driver itself, we cannot assess this externally or by any spec.

Speakers like ATC, certainly the bigger models, use large diameter (though sometimes rather short) voice coils that will more effectively dissipate heat. Large voice coils (+3") generally are not not implemented in low(er) efficiency hi-fi speakers, and so thermally are more challenged. Moreover many ATC speakers - when best, to my ears - are actively configured, and this makes them impervious to the influence and effect of a passive cross-over at higher SPL's, while also having the amplifiers work seeing into an easier load - all of which contributes to a sound that is less "stressed" at higher levels. 

Nothing “special” bout them. 
   You may need a more powerful amp. 
  Or depending what the speaker load is 4Ohm?

  Mine are somewhat higher, BUT, the highs are rolled off, so they seem and ARE warmer sounding. Recording dependent is huge, a good recording is fine, a HOT recording will sound too bright, even on my speakers 

especially the scorpions remasters several years ago, they are so bad, it’s like the sound guy, pushed up every lever of the treble, they are not even listenable,......which is why I use my old original pressings. 
    I personally like warmer speakers, so, if you like the sound of them, keep, and enjoy the NON fatiguing sound. 
Enjoy. 

Focusing on efficiency as a measure of speaker technology or quality is like judging a passenger car based on miles per gallon.  MPG does not measure or reflect the quality of seating, the quality of materials in the car, the car's performance, its reliability or safety.   There have been many terrible high MPG cars that are uncomfortable, don't handle well, don't look good, are unreliable and unsafe.  

Brad