Horns: Why don't they image well?


Anyone have a theory?

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erik_squires
Horns use a very large waveguide - the energy arriving is not a point source for all frequencies they produce  - imaging therefore suffers slightly. The shape of the horn is critical - large spherical horn designs will image best - like Avantgarde. Intermediate horn designs suffer most. Very small horns like the waveguide on a tweeter also work perfectly because they are small enough not to affect imaging.
stirring the pot again......
stirring the pot again......

I admit it, it's true. But I learn a great deal this way too. :) 
Eric,

Why don't you design and build a pair of horn speakers that Images well, and then report back to us? Get yer tools out..........
3 way please................

@gawdbless 

You seem a little bruised. 

Another horn thread.
I’m looking for something that hasn’t been said before. 

Eric,

I was being serious in a jokey way, you seem to knowledgeable  about speakers, cones, crossovers from your posts etc.
It certainly might be a time consuming challenge for you.
My Nagaoka BLH with a single Fostex Sigma 168EZ? 6" cone image quite well.
Another horn thread.
I’m looking for something that hasn’t been said before.

You seem new here... 
@Erik,

He is. I think every possible subject regarding hi-fi has come up already in the past decade or two.....Welcome wcfeil!
Set them up right and they can image just fine.  

My Klipschorns are set in two corners approx 13' apart room length 17'.  They seem to Image just fine to me. Then again, what do i know?
Need big enough room, and enough space from the horns for the waves to disperse proper. Smith horns suck in small rooms.

No idea. I’m only dropping in because, although I’ve heard horn designs here and there over the years, I wish I had more experience with them.  (My room set up has never favored horns, though).

Just for clarity: what exactly do you consider to constitute a horn design? Is it any speaker that uses some form of wave guide?

I felt the jbl Everest speakers were the best (or at least my favourite) at the last audio show I attended. Beautiful timbral reproduction of an orchestra, great dynamics, and I don’t seem to remember thinking the imaging sucked. But then again I’m not sure how much I was paying attention to that.
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>>you seem new here<<

And you haven’t done your homework Skippy. 
Need big enough room, and enough space from the horns for the waves to disperse proper.

Bit late now, I already have them.lol.
Of course they can go ear bleeding loud if one desires, of which I do not do. My level is always  (mostly) a sedate listening level, after all don't want the kitties to do 'a runner' do we? 
How large a room would you say is adequate for the Klipschorns?
Anyone else think my room is not large enough?
Your room is on the very edge of what i would consider large enough.

My room is 15.5 x 26 and I have them on the short wall. Imaging is as good as speakers up to the 15k price point that have graced this room. Extremely happy!

Oz
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@ozzy62,
I have the possible option of taking down a wall and therefore gaining another 17' or so. although the width would remain at 13'.  I just have to bend a certain ear that I am listening to close as horns need to be blasted, not to mention they have no precision and I could loan them to the Broncos if they need a PA system..........
It presents a different perspective than dynamic speakers. I was a very long time electrostat listener (started with old Quads in 1973). I switched to horns (Avantgarde Duo) and SET (Lamm ML2) in around 2006-7. 
A much more 'in the room' presentation, very dynamic, biggest drawback has nothing to do with image, but continuity with bass. 
Frankly, many of the audiophile attributes go out the window for better or worse-- that 'performers in the room' quality is something that gives me a very good sense of the stage if there is one on the recording. (Sometimes it is simply a concoction of multi-tracking). In an appropriately sized room, the overall presentation is sizable and depending on source material, very dimensional.  Much of the dimensional quality I attribute to the upstream components. For example, changes in phono stage made a considerable difference in the very specific placement of instruments. 
All that said, this does not sound like a good dynamic speaker system, something I can also enjoy if it is well assembled and set up in the room. 
I've had pretty good sounding rooms for these systems over the years and that also plays a big part. There is magic in horns + SET if it grabs you the right way. And I've heard my own speakers sound pretty terrible with the wrong amp. 
@gawdbless
based on my research i’d want a room of at least 150m3 also personally i’d rather go for a pair of jubilees over kilpshorns
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Love the topic! Thank you Eric!!

Most horns are designed with acoustic amplification as the top priority. A few are designed with low coloration as the top priority, Some of those have the potential of imaging well.

I’ve been working with horns and waveguides for many years now, and during this time I’ve had the privilege of working with Earl Geddes, whose waveguide-based designs (a waveguide being a particular type of horn in this context) image extremely well and totally disappear as the apparent sound source.

Okay time to get nerdy: The ear/brain system gets its localization cues from the first approximately .68 milliseconds of sound. In that time, sound travels about 9 inches (corresponding to the distance around the head from one ear to the other). A poorly designed horn has lots of opportunities to screw things up within this time window.

Reflections and diffractions within the horn will happen during that first .68 milliseconds. Diffraction (from sharp edges and discontinuities) is worse than reflections. Reflections within the horn are inevitable, but some geometries generate more internal reflections than others, and/or direct more of these internal reflections towards the listener than others.

My understanding is that the best horn geometry from the standpoint of internal reflections is the Oblate Spheroid (what Earl uses). I use a Super-Elliptical Oblate Spheroid which comes very close, and which may have a couple of advantages in other areas.

So to sum it up, proper horn geometry is absolutely crucial if imaging matters. Most horns screw up that first .68 milliseconds of sound, but a few are benign in this respect. Those are the ones that have the potential to image well.

Here is a link to a show report that comments on the imaging of one of my systems. My room is covered starting about 1/4 of the way down from the top of this page, and the writers are Tyson and Pez (Jason) from AudioCircle.com, who for several years (before they burned out) were arguably doing the most precise show reports of anybody because they pre-selected their rooms, listened to the same few short revealing tracks in each room, wrote quickly, and then moved quickly to the next room on their list:

https://www.audiocircle.com/index.php?topic=120504.msg1267150#msg1267150

In his subsequent "Best Of" report, Pez had us tied with several rooms for second place. For some reason I can’t post the link. Anyway, he wrote: "This room had the most locked in soundstage and imaging I have ever heard bar none with dynamics to match. The sweetspot is just an incredible experience and really musical top to bottom."

Did you catch that? A HORN system had "the most locked in soundstage and imaging I have ever heard bar none".

Tyson had us tied with one other room for first place and wrote: "Basically did everything as well or better than any other speaker at the entire show... And, amazingly, they did it with zero room treatments."

(We have good radiation pattern control and we aim those patterns intelligently, so we can get away without room treatments if we want to.)

If anybody is going to be at RMAF 2018 next weekend, you are invited to Room 3002 to find out firsthand whether or not "horns done right" can image well, and/or otherwise compete on the basis of freedom from coloration, natural timbre, disappearing as the apparent sound source, precision, and whatever else horns traditionally are presumed to not do well.

Duke

got dogs in this fight!

I think horns don't image as well as the others. But what you give up in imaging you get in a wider, bigger picture of the sound.  
The problem is the interconnects and speaker wire......
Oh Erik!I am really disappointed in you...and I'm not saying that tongue in cheek either! First, let me say that I have deliberately not read any of the other responses before writing my own. Let me just say that I have owned some vert fine speakers , known for good imaging such as Proac, Nestorovic, Dahlquist Focus Audio and many others. My Klipsch Epic CF-4 speakers image as well as any of them, and larger than most of them. 
I know that you're a smart guy, and much more knowledgeable  than myself, so I will only say that if you truly believe that horns don't image well, you must not have listened to the right ones yet. If you're ever in the Phoenix area, please drop in! 
@audiokenesis
what horns will be in room 3002?
It maybe the speakers in the link he posted. hey Duke can you please confirm what speaker/s you will have in the 3002 ?
I hope to pop in, nay WILL pop in.......
@roxy54 

Ooooh, my bad. I meant to post "Why do horns image SO well." 

I guess I screwed that up... << runs and hides >> 

@d2girls asked: "what horns will be in room 3002?"

One of mine, a new model making its debut. It’s called the Azel Stand Mount, and it’s not up on my website yet.

12" midwoofer, 1" throat Beryllium-diaphragm compression driver on a 15" SEOS waveguide-style horn. Rear-firing tweeter compensates for a radiation pattern mis-match between midwoofer and horn by fixing the spectral balance of the reverberant field. Crossover is kinda neat in a kinda nerdy way... starts out first-order and then accelerates to fourth-order.  Two pluggable ports to work with different boundary reinforcement situations, and user-adjustable treble-tilt via a high-quality external resistor. 

@gawdbless asked: "hey Duke can you please confirm what speaker/s you will have in the 3002?"

The entire system also includes the new "SuperStands" (so named because there just isn’t enough hyperbole in high-end audio these days). The SuperStands incorporate a built-in subwoofer and an adjustable coaxial driver dedicated to the reverberant field, the latter being an application of the "Late Ceiling Splash" and/or "Space Generator" concepts I’ve shown with a few times. The SuperStands will theoretically work with most stand-mount speakers.

Finally we’ll have two (optional) outboard subs positioned somewhere in the room, so that we’ll have four distributed subwoofer modules in total. Placement flexibility is not quite as good as with the Swarm because two of the subs are stuck doing double-duty as speaker stands, but we still expect to get pretty good modal smoothing.

"I hope to pop in, nay WILL pop in......."

SWEET!! Looking forward to it.

Didn’t you show a killer system with Mangers in a rounded upper cabinet once upon a time?

Duke

@erik_squires -
There was a litigant who wrote something really nasty- a paragraph's worth- about the judge and when he got hauled in front of the court on a contempt motion, his defense was;
"Oh, sorry, your Honor, that was a typo." :)
@duke,  Didn’t you show a killer system with Mangers in a rounded upper cabinet once upon a time?

your not addressing me are you?
If you are then, er, not I........

Ooops, sorry gawdbless! My mistake. Must be getting old.

I miss my memories... I think.

Duke

@gawdbless and @d2girls, you might also want to check out Room 542, where Peter Noerbaek (of PBN) will be showing his M2!5’s... same horn and compression driver as the JBL M2, but TWO of the M2’s woofers, if I understand correctly. My guess is that speaker will do a LOT of things very well. Assuming I get a chance to sneak away at some point, probably Sunday morning, THAT’s the room I’m heading for.

Also I plan to hit the Classic Audio Reproductions room, a perennial favorite of mine, another big and actually beautiful horn speaker with amazing field-coil drivers. 

D2girls, you’ve got JBL 4367’s, right? So you are done with speaker shopping. But if you don’t mind, I’d love to get your brutally honest opinion of how my system compares.

And in my comments above where I was talking about reflections in horns, I forgot about this latest generation of JBL horns. I think their unusual internal geometry is specifically aimed at making sure internal reflections are directed away from the listener, and I bet they do an excellent job of it.

Duke

Horns: Why don’t they image well?

Horns can image very well, I find - certainly going by my own all-horn speakers. Perhaps there’s an aspect of horn speakers imaging differently compared to direct radiating speakers due to their dispersion characteristics of directivity, and hereby limiting to an extend early reflections and room interaction as a whole (i.e.: a relatively bigger share of direct sound than reflected ditto), but as perceived sound I find it makes less sense with such a distinction. Whether horn speakers in general (and they span a variety of iterations be that from mostly hybrids to the more rare all-horns and everything in between that, frankly, makes broad statement to claim one or the other seem somewhat befuddling) are to be found to image badly should fall back on one’s (perhaps lack of) experience with horn speakers or be a matter of mere preference due to "something other" about the way they image, that may even have one believe they don’t image at all.

Another aspect comes to mind, and that’s the typically more pronounced sensation of solidity or density and presence in the sound of quite a few horn speakers, that can be perceived as less airy and more as a quality (to some at least) as music happening in-the-room kind of way, that deters from a more a laid-back, "thinner," behind-the-plane-of-the-speakers and at-arms-length sound that may "stimulate" the sensation of imaging. I find the latter quality beguiling, but ultimately prefer the former as the more uninhibited and natural/live presentation.

Many ways to skin your cat, really. JMLC horns can sound wonderful, OSWG’s I’ve owned (and yes, they image very well), and currently, for the last almost three years I’ve used horn speakers with Tractrix mids and tweeter horns (and folded bass horn) which throw a very convincing stage in front of me (they’re present sounding; not in-your-face). Never heard conical horns the likes of OMA, but in any event I find singling out particular horn geometries as "the best" to be more of a marketing ploy to boost business than a marker of the diversity of great sounding horns out there.
Some horns image great depends on the horn dude!!!!!
Higher speaker SPLs mean worse room acoustics problems. I.e., comb filter effects (not good for imaging).
Perhaps some horns don’t image well but the Avantgarde Trio’s I heard some 20 years ago imaged spookily well off an old vinyl playing a Jazz combo.

The only other speaker that came close for sheer imagery alone was an old Quad 57 channeling some male opera voice. The tightness of the image was uncanny. I bought them, and they were just average on Springsteen. They needed space and I didn’t have any.

Is it fair to say that (as well as a suitable recording) plenty of space behind the speaker is essential for good imagery?



Lots of speakers don’t image well. Everything is relative. It’s not black and white. 🦓 Define image. The imaging is not dependent on speakers anyway, at least not entirely. Not by a long shot. Hel-loo!
Hey ozzy,

Are your Klipschorns stock or have you done any of the usual or unusual tweaks/upgrades?

@phusis wrote:  " but in any event I find singling out particular horn geometries as "the best" to be more of a marketing ploy to boost business than a marker of the diversity of great sounding horns out there."

My statement about the Oblate Spheroid profile was based on my understanding that it is the mathematical optimum for minimizing detrimental internal reflections within the horn.  There are other profiles optimized for other things - minimum phase, wavefront preservation, etc. 

Duke

Is this thread serious ? Enjoy ! MrD.
Is this thread serious ? Enjoy ! MrD.

Up there with the best........
What rankles you sire?
I replaced the AA xovers with Volti Audio xovers and damped the mid horn with modeling clay.

Oz

Oz,

How much does the Volti Crossovers Improve the sound of the originals? Mine has the AK3 installed. I've already bought the Volti Mid range throat,  and am going to try the original mid range cone to hear what they sound like with a 2" throat, if not very good then will try and save the pennies for the BMS mid range and crossover and........

Sorry Eric for sort of hijacking your post. 
I thought it was a nice improvement. And my AAs had been recapped, the volti was still better .

If I'm not mistaken, if you change to the BMS driver, you can't use the klipsch xover.
yes, I will have to buy a volti crossover to use the BMS mid range cone. Which are about $1300 approx for the pair. I have been talking to a chap who has gone the whole 9 yards with Volti upgrades and he says its absolutely worth the expense.