Higher sensitivity - more dynamic sound?

A 110db horn running off 20 watts will not see any heat that can cause compression a 86db speaker requiring over 250 watts will be near melting at peak SPL levels. A horn also has better throw so at distance, its SPL level isn't dropping as fast as a standard dynamic speaker design. Standard dynamic designs can sound pretty darn nice but they are toys when compared to a proper large horn speaker. Now I know most cant house anything over a toaster-sized box or overly slim tower and they don't want to consider that larger is better even though the brand of small boxes they bought most likely has a much larger model as the top of the line.

@johnk , I see no physical mechanism by which a horn speaker would throw better than a dynamic speaker. The impedance matching improves efficiency, but it is still effectively a point source so it must follow the inverse square law.  Only a line array and the equivalent electrostatic or planar speaker would have improved throw. The room response would be different though. @audiokinesis can you comment on room response of line arrays?

@atmasphere @audiokinesis , I expect that electrostatic speakers and large planar speakers must be fairly immune to these power compression / thermal modulation effects within limits?  By virtue of the large number drivers and small amount of power per driver, line arrays must be pretty immune as well.

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!

@deludedaudiophile wrote:

"can you comment on room response of line arrays?

"... I expect that electrostatic speakers and large planar speakers must be fairly immune to these power compression / thermal modulation effects within limits?"

The room response of a given line-array system depends on the specifics. Obviously at frequencies where they approximate a line source the sound pressure level is falling off at about 3 dB per doubling of distance rather than the normal 6 dB per doubling of distance, not counting the contribution of reflections. There are of course tradeoffs to be juggled.

If small fullrange drivers are used, they beam moreso than most tweeters in the horizontal plane, resulting in a pretty big spectral discrepancy between the direct sound and the reflections. If tweeters are stacked alongside midwoofers, the frequency response in the crossover region changes significantly with the horizontal angle. If there is a central tweeter flanked north and south by stacked midwoofers, the tweeter may not approximate line source behavior as well as the midwoofer array.

All of that being said, with a line-source-approximating speaker the direct sound tends to be more dominant than with a point-source-approximating speaker, so I’m not sure how audible the aforementioned off-axis anomalies tend to be in practice.

Electrostatic speakers can have compression from transformer saturation at high power levels, and in extreme cases the transformer can overheat and melt. My impression is that in general they are less prone to compression than cone-n-dome speakers, but also less efficient and/or more difficult to drive, and in general will not go as loud as comparably-priced cone-n-dome floorstander speakers.

Single-ended planar magnetic speakers, those having magnets only on one side of the diaphragm, have a compression-ike mechanism because of the non-linear motor; that is, the motor strength decreases when the panel is further from the magnet, and increases when the panel is nearer the magnet, such that motor strength available for the higher frequencies is modulated by the lower frequencies. A push-pull motor structure eliminates this effect. I don’t know much else about compression mechanisms specific to planar magnetic speakers, but I am not under the impression that they are champions in the realm of dynamic contrast.

Loudspeaker/room interaction happens to be something that I give high priority to. The two types of speakers I sell are large, curved, line-source-approximating fullrange electrostats, and hybrid horn systems. I think full-range horn systems can be superb but they are inevitably larger than what I want to work with.

Duke

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.