Higher sensitivity - more dynamic sound?

Both speakers can have the same dynamic range assuming a sufficiently powerful enough amp for the lower efficiency speaker.

@jonwolfpell This statement is false; the reasons why explained on the first page of this thread.

Electrostatic speakers can have compression from transformer saturation at high power levels

Just to clarify on this comment, at the point the transformer saturates it will also be making distortion and thus describe an upper limit on the range of the speaker. Sound Lab is known for using dual transformers, one for bass and one for treble to get around this problem a bit.

The 86dB efficiency speaker on a 250W amp has more total dynamics to cover incoming source material of a wider dynamic content than the 102dB/20w amp system.

Huh? Why? The dynamic range is a function of the recording being played back. Its not as if a system using more sensitive speakers is somehow only being fed signals of less dynamic range :)

The 250 Watt amp has slightly over 10dB more power than the 20Watt amp, but the 102 dB speaker has 16dB over the 86dB speaker; your numbers don’t seem to add up.

Or am I misinterpreting what seems to be written here?

@deludedaudiophile ESLs are immune to this problem as I stated earlier since their MO uses a power supply plugged into the wall. Field coils are as close as you can get to this with ’conventional’ drivers. Of course both technologies do have their practical limits. Both easily measure and sound more dynamic than their permanent magnet cousins.

IMO/IME your surmise about horn speakers isn’t quite correct (although we are starting to see more line arrays in PA applications). You may not be taking into account the controlled directivity of horns which line arrays and planars lack.

In a home instead of a PA application, you are probably correct since the energy needed to fill the room is so much less. But some horn systems are pretty efficient; over 104dB and so only need a fraction of a watt for 90% of all listening. ESLs and all the line sources I’ve seen so far need considerably more...

@audiokinesis Thanks Duke!

Is there a hardcore technical speaker designer in the house?

@deludedaudiophile there is- his name is Duke @audiokinesis 

I would think that the frequency effects of compression would be more worrying than a change in maximum output?

@deludedaudiophile Good point and one more problem to add to the list...  If the speakers are inefficient, powering them really won't help the dynamic issue. You simply need greater efficiency to get around that.

Higher sensitivity is better as long as its not achieved by simply paralleling drivers, resulting in a lower impedance.

Lower impedance causes amplifiers regardless of type, to make more distortion.

If the speaker is low sensitivity, one common result is something called 'thermal compression' where the voice coils heat up with things like bass notes, causing the driver to be less efficient. This is quite audible and is why people with horn speakers often talk about how much more dynamic they are.