I am pretty impresed by all this technical oriented discussion. But I am also surprised that few people discussed how HE speakers sound like.
I need to mention here that HE speakers where originally build for disco and masses.
Actually, no. The first dynamic loudspeakers ever made, way back in the 1920-ies were, er, high efficiency designs. It was decades later, from roughly early 60-ies onwards, particularly in England, that people like the late Raymond Cooke (founder of KEF) started to introduce low efficiency through their quest for stiffer bass membranes. Others, even then offering aluminium cones, like Jordan-Watts, were sent off with comments like the one above.
And I have to disagree with all that stuff about micro-dynamics. I've heard several HE speakers - NONE was able to properly reproduce ANY dynamics, transient or whatever you wanna call it. In today world anyhow most of the speakers are built around 90db.
You were exceptionally unlucky, believe me. But you are right in one thing - when a manufacturer, any manufacturer, has only HE as a card to play with, the sound is not very likely to be much good. HE is only one of a string of objectives which need to met, or, put differently, it will not replace or invalidate other quality speaker aspects.
Talking about driveability - there are 2 other important factors:
- the high-curent delivered by amplifier and
- the impedance
Assuming high current requirements from the speaker, and assuming it is in addition a downright evil load, what do you think, which will tax an amp more, a HE speaker or a LE speaker?
Consider: your 90 dB speaker and a say 96 dB speaker. Under the above conditions, your 90 dB speaker will require four TIMES the power of the HE speaker for the same SPL. So, which one will suck the amp dry first?
I just listened yesterday a pair of floorstanders rated VERY conservative 87db. And they were driven more then loud by a 12W amplifier!!! Why is that? Because the speakers were in 8 ohms and because the amplifier delivered incredible high amoutns of current.
How big was the room? What were its acoustic properties? What kind of music was being played? What were the require SPLs?
As for "incredible amounts of current", I wonder what a 12W amp can deliver to be called so? Let's do some math: let's say the amp is a true voltage source (the ideal amp), and that it delivers the same voltage across anything we want to call a load. So, it should deliver 12/24/48 watts into 8/4/2 ohms, which is 1.73/3.46/6.92 amps.
In amp terms, that's nice, but far from impressive. A stock Yamaha integrated amp, AX-592 (1998), will deliver peak outputs of 470 watts into 2 ohms no problemo, which means peak currents of 21.7 amps. A nominally lowered powered Harman/Kardon 680 integrated amp (1999) will kick 540 watts into 2 ohms in peaks, which is 23.24 amps. These are regular, off the shelf units, and far from being alone - Rotel, NAD, Denon and many more will do about the same.
Careful with those power rating comments.
Horns? As I said - Music for the masses
Some, perhaps even most, are probably orientated towards the masses, but some, as in case of some high end JBL and Klipsch designs, to name but two, put out such sound that few, VERY few can even hope to match.
Beware of sweeping statements; they hardly ever stand in audio for long.
Cheers,
DVV