How come Horn + woofer designs are not more popular?

@mijostyn --

Another issue that bothers me a little is the assumption that horns are more dynamic than other speakers. Horns are more efficient than most other speakers for sure but any speaker can be just as dynamic given enough power and power handling capacity.

That’s just the problem; with less efficient speakers and a sensitivity typically below 90dB’s "enough power" for proper dynamic envelope will largely be converted into heat in the voice coils (and crossover components as well). Depending on one’s size of listening space, distance to the speakers, room-acoustic characteristics etc. the power capacity needed for reasonbly uninhibited, realistic dynamics can very easily reach hundreds of watts, with thermal issues and power compression looming closely or already in full display eating away precious dB’s.

Imagine a not uncommon sensitivity of a direct radiator speaker sitting in the 84-87dB range compared to an all-horn speaker of 104-107dB’s sensitivity (or a horn hybrid sitting between 94-97dB’s, which will also make a big difference with ~1/10 the wattage requirement). The latter will need ~1/100 of the power - probably even less when we factor in power compression - to generate the same SPL as the former, and so full dynamic capacity with an all-horn setup, in a domestic environment, can actually be achieved close to realistically without thermal issues, and headroom to spare. And this, headroom, is hugely important. It’s not only about having "enough;" it’s about having sufficient headroom, even through blasting crescendos, for the speakers and amp(s) to more or less ease along so that the actual perceived sonics feel "at ease."

In the search for dynamic prowess it's also worthwhile to look at the possible sonic implications that follow with the  process of acoustical impedance transformation. A horn couples the cone movement to the air gradually and more efficiently than a direct radiator, and this impedance coupling "latches" the cone movements to the air in such a way, to my ears, that transient snap and dynamic feel (and presence) is heightened. The cones in all-horns also move much less for the same SPL, and therefore inertia is greatly reduced for even better transient abilities.

Headroom, again, is very important. I’d even go so far to state that for headroom to be sufficient, all-horn or horn hybrid setups with ~+97dB sensitivity is a minimum requirement if we’re to attain fairly realistic and effortless dynamics. A radical thought to some, I’m sure..

Horn speakers may have an absolute higher volume level at a given distance but very few of us listen at those levels. Our ears do have a pain threshold.

Most compressed music has limited dynamic range, and thus quite easily feels rather loud. Music not severely compressed will retain dynamics more realistically, and the average volume will feel lower. It’s not as much about loudness per se as it is ease and the overall feel of the music, and a setup sonically at ease will sound subjectively lower (but we should still be aware of SPL’s to spare our ears). When I listen to a proper all-horn setup the uninhibited presence and size/scale is addictive, and makes most direct radiators I’ve heard seem rather tame/less alive and malnourished by comparison. Many mayn’t expect it, but quality implemented horns have a warmth and vibrancy and easy-on-the-ears imprinting that’s anything but strident, shouty, nasal, hard or what have you.

I'm not actually in your discord, but who else in your group has 4367?

Phusis, all that is nice but relative to what? We are not trying to blow up the Empire State Building. If you like pea watt amplifiers then you need all the efficiency you can get but in real life you can get all the volume and dynamics you need with dynamic drivers and good powerful amps. I am a linear array ESL fan and I guarantee you will never get as realistic a presentation out of a horn system all that rubbish aside.

Mike 

Not everyone has enough lines in their house to energize all those panels. Even a pair of Stax ESL 4X are going to draw 4000w idle.

I’m not being facetious guys. I am trying to learn here. Way back I had Heresys and I loved them. In 1970 we did not have much for power. With a Dynaco Stereo 120 these things would rock. No deep bass but then nobody knew about sub woofers. They were three way. So let’s assume we are using a 12" woofer infinite baffle and cross at 1000 Hz to a horn, what does it take to make a horn go from 1 to 20K with reasonably even dispersion and not sound like a goose honking. Duke’s Speaker has multiple other drivers including three tweeters firing out back along with whatever is in the LCS box. It is anything but a two way hybrid horn speaker which to me means one horn and one woofer. I have never heard Duke’s speaker and I am making absolutely no comment on their performance.

@mijostyn Thermal distortion caused by instantaneous voice coil heating is why horns tend to be more dynamic than regular box speakers- horns are really the only way to keep up with ESLs in this regard.

Regarding your question above- cross the horn at 500Hz and you have no worries with the woofer doing everything below that. Duke’s speakers are usually two way designs; the other drivers you see in the online photos are the late ceiling splash drivers. So concentrating only on the two-way aspect, Duke has often used a wave guide horn that looks a bit like a trumpet mouth giving even forward dispersion in both vertical and horizontal planes. I don’t know where Duke crosses his speakers over but I do know he spends most of his time sorting out the crossover to deal with the peculiarities of the drivers themselves- this is the thing at which he excels.


At any rate, modern horns are pretty well sorted and have been for at least the last 20 years. The real trick lately has been getting the driver to interface properly to the horn- so throat designs have improved simply through computer optimization, and after only about 60 years driver manufacturers sorted out that if they had a better surround than just the material of the diaphragm itself, that they could get wider bandwidth and less breakups. Its these latter two things that have caused modern horns to be as smooth as any other loudspeaker technology.