Klipsch Klipschorn AK6 loudspeaker Measurements

Sidebar 3: Measurements

Because of the Klipschorn AK6's bulk—each weighs 220 lb—I drove my test gear the 177 miles to Art's place and measured the speaker sitting on a furniture dolly in his driveway. I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Klipschorn's behavior in the farfield and an Earthworks QTC-40 mike for the nearfield responses.

Klipsch specifies the Klipschorn's sensitivity as 105dB/2.83V/m, which is extraordinarily high. My estimate was lower, at 101.1dB(B)/2.83V/m, but this is still the second-highest sensitivity of all the speakers I have measured over the past 30 years. (The highest was the Auditorium 23 Hommage Cinema, which features a measured voltage sensitivity of 102dB(B)/2.83V/m.) The Klipschorn's sensitivity is a whopping 18.6dB higher than the sensitivity of the BBC LS3/5a I always measure at the same time I test a speaker (to ensure that I haven't made an error in setup). This speaker will play loudly even with flea-powered amplifiers driving it. And at typical listening levels, the drive-unit diaphragms will hardly be moving, which implies low distortion.

Klipsch specifies the Klipschorn's nominal impedance as "8 ohms compatible." This is optimistic: Not only does the speaker's impedance magnitude (fig.1, solid trace) drop to 3 ohms in the midbass and 2.7 ohms in the upper bass, but the electrical phase angle (dotted trace) is sometimes extreme. There are current-demanding combinations of 4.1 ohms and –43° phase angle at 44Hz and 4.1 ohms and +43° phase angle at 139Hz. Despite its very high sensitivity, the Klipschorn will not be at its best with amplifiers that are not comfortable driving 4 ohm loads.

819Klipfig01

Fig.1 Klipsch Klipschorn, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

In addition, the very large difference between the average impedance in the bass and the rise to 20.7 ohms at 1.5kHz means that the speaker's perceived tonal balance will be very dependent on the amplifier's output impedance. For example, as I always do, I used my solid-state Krell KSA-50 amplifier for the acoustic measurements, which has a measured output impedance of 0.13 ohms from 20Hz to 20kHz. To investigate the interaction between the Klipsch's impedance and the amplifiers used to drive it, I measured the speaker's farfield response on its tweeter axis with the Krell (see later), then repeated the measurement with the tubed Shindo Haut-Brion amplifier that Art Dudley used for much of his auditioning. The difference between the two responses, which were normalized at 1kHz, is shown in fig.2. I don't know what the Shindo's output impedance is, but it must be high, as this amplifier tilts down the Klipschorn's response above 2kHz, with the difference between the response with the Shindo and the Krell reaching –10.7dB between 11kHz and 13kHz.

819Klipfig02

Fig.2 Klipsch Klipschorn, difference in the anechoic response, 300Hz–30kHz, on tweeter axis at 50" due to substitution of a Shindo Haut-Brion amplifier for a Krell KSA-50 (5dB/vertical div.).

This might seem less-than-optimal performance on the Shindo's part. However, when I asked Art to let me listen to music with the Klipschorns using first the Air Tight ATM-300 amplifier that he reviewed in February 2019, which has a low output impedance of 1.2 ohms from its 8 ohm output transformer tap, then the Shindo Haut-Brion, the latter gave the best sound. Yes, the balance with the Shindo lacked top-octave air, but the high frequencies were exaggerated with the Air Tight, there was no low bass, and the midbass sounded lightweight. Low-frequency extension was still absent with the Haut-Brion, but the midbass now sounded in better balance with the midrange. The sound of this loudspeaker will be very dependent on the amplifier it is used with.

While there are discontinuities in the impedance traces that would imply the presence of resonances of various kinds, with a horn speaker these might also be due to the effect of reflections from the horn's mouth. The only part of the two enclosures where panel resonances might give rise to audible problems is the front of the woofer bin. When I investigated this panel's vibrational behavior with a plastic-tape accelerometer, I found a fairly strong resonant mode at 316Hz, with others almost as strong to either side of it (fig.3). There were also some low-level modes in the upper bass. I could just hear these modes with the noise-like MLSSA signal and my ear close to the panel. They might not be significant with music, therefore, other than perhaps adding some midrange congestion with some kinds of music.

819Klipfig03

Fig.3 Klipsch Klipschorn, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of woofer bin front panel (measurement bandwidth, 2kHz).

The Klipschorn's impedance- magnitude plot has a single peak in the bass centered on 36Hz, suggesting that this is the drive-unit's fundamental tuning frequency. The red trace in fig.4 was taken with the microphone close to one of the low-frequency horn openings; it indicates that the woofer's output rolls off sharply below the tuning frequency. There are also significant peaks in the woofer's output at 103Hz and 190Hz, which I could hear with the MLSSA signal as a "hooty" quality.

819Klipfig04

Fig.4 Klipsch Klipschorn, acoustic crossover on tweeter axis at 50", corrected for microphone response, with the nearfield woofer response (red) plotted below 675Hz.

I plotted the output of the woofer in fig.4 at a level where it crossed over to the farfield response of the midrange unit (blue trace) at the specified 450Hz. The woofer rolls off rapidly above that frequency, but this graph does suggest that the woofer's level is somewhat lower than the midrange's. The midrange unit crosses over to the tweeter (green trace) a little lower in frequency than the specified 4.5kHz; while the rolloff is fast, a couple of resonant modes are visible. Driven by the Krell amplifier, the tweeter appears to be balanced on average 3dB too high in level, with a 6dB-higher peak between 8kHz and 11kHz and a sharp rolloff above 18.5kHz.

Fig.5 shows the Klipschorn's farfield response, averaged across a 30° horizontal window centered on the tweeter axis. Again, the tweeter appears to be too high in level. Some sharply defined suckouts are visible between 2.5kHz and 4.5kHz. The farfield responses in figs.3 and 4 were taken with the grille in front of the midrange and treble horn openings, as that is how Art Dudley performed his auditioning. Removing the grille and repeating the farfield measurement suggested that these suckouts filled in to some extent. Note that I haven't plotted the response below 350Hz in fig.5, as the horn-loaded woofer's output in free space wasn't fully captured within the gated time window. (For this kind of measurement, the FFT is applied to the portion of the impulse response before the first reflection of the sound, which in this case will be from the ground in front of the loudspeaker (footnote 1.)

819Klipfig05

Fig.5 Klipsch Klipschorn, anechoic response on tweeter axis at 50", averaged across 30° horizontal window and corrected for microphone response.

The plot of the Klipschorn's horizontal dispersion (fig.6), normalized to the response on the tweeter axis, is complex. Disregarding the off-axis peaks, which will be due to on-axis suckouts filling in to the speaker's sides, overall the speaker is more directional through the midrange and treble than a conventional, direct-radiator design. This graph also suggests that in free space the woofer horn offers a higher output to the speaker's sides than it does on the tweeter axis. However, that suggestion is incorrect. What is happening is that the time delay affecting the woofer's output (see later) is reduced to the speaker's sides, meaning that more of it is captured in the gated time window. In the vertical plane (fig.7), the on-axis response is maintained over a wide ±10° window. This is a good thing as the tweeter is 51" from the floor and the average listener's ears are 36" high. I do note, however, that AD's listening chair places his ears closer to 45" from the floor.

819Klipfig06

Fig.6 Klipsch Klipschorn, lateral response family at 50", normalized to response on tweeter axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

819Klipfig07

Fig.7 Klipsch Klipschorn, vertical response family at 50", normalized to response on tweeter axis, from back to front: differences in response 10–5° above axis, reference response, differences in response 5–15° below axis.

In the time domain, as with the Auditorium 23 horn-loaded loudspeaker, the Klipschorn's step response (fig.8) is complicated. The problem with a loudspeaker using horn-loaded drive-units but with the horn openings in the same plane is that the outputs of the drive-units arrive at the microphone or the listener's ears at different times, due to the different lengths of the horns. While all three drive-units are connected in positive acoustic polarity, the tweeter's output—the upward-moving spike at 4ms in fig.8—arrives first at the microphone. The output of the midrange unit doesn't arrive at the microphone for another 1.5ms, while the woofer's output is too late to be shown in this graph. (Separate measurements of each drive-unit indicate that the woofer's output arrives 6ms after the midrange unit's.) Does this matter? In theory, even the woofer's output is within the hearing system's tolerance for different arrival times (footnote 2).

819Klipfig08

Fig.8 Klipsch Klipschorn, step response on tweeter axis at 50" (5ms time window, 30kHz bandwidth).

But from my own experience with truly time-coincident, multiway loudspeakers like Quads and Vandersteens, where the outputs of all the drive-units arrive simultaneously at the ear, I feel such time delays smear and obscure stereo imaging precision.

The difference in arrival times of the tweeter's output and that of the midrange unit can also be seen in the Klipsch's cumulative spectral-decay or waterfall plot (fig.9). This graph is difficult to interpret, but the different arrival times make it possible to calculate individual cumulative spectral decay plots. Fig.10, therefore, shows the midrange unit's waterfall plot. It is fairly clean, though with several spikes of low-level delayed energy visible above the crossover frequency to the tweeter. The tweeter's waterfall plot (fig.11) reveals a clean initial delayed energy, but again there are some ridges of delayed energy at the top of its passband.

819Klipfig09

Fig.9 Klipsch Klipschorn, cumulative spectral-decay plot on tweeter axis at 50" (0.15ms risetime).

819Klipfig10

Fig.10 Klipsch Klipschorn, midrange unit only, cumulative spectral-decay plot on tweeter axis at 50" (0.15ms risetime).

819Klipfig11

Fig.11 Klipsch Klipschorn, tweeter only, cumulative spectral-decay plot on tweeter axis at 50" (0.15ms risetime).

The Klipschorn's measured behavior reveals that the performance parameters that are generally held in the 21st century to correlate with good sound quality in both the time and frequency domains have been compromised to achieve that astonishingly high sensitivity. Its sound will also be heavily dependent on the amplifier with which it is driven. I don't recommend using a typical solid-state design with the Klipschorn because the region covered by the tweeter will be too hot.

I wasn't too surprised by the Klipschorn's limited low-frequency extension despite its size. I was reminded of the impact Acoustic Research's first loudspeaker, with its relatively small sealed enclosure and "acoustic suspension" woofer, made in the mid-1950s. "My measurements showed that my little prototype had better bass and less distortion than anything on the market, yet it was one quarter the size," wrote AR's founder, Edgar Villchur, adding "I thought, 'This has got to be the future of loudspeakers.'" (footnote 3) It was.

Multiway loudspeakers with horn-loaded drivers but a flat baffle can be made time-coincident with digital signal processing. As the Klipschorn has separate input terminals for each of its three drive-units, I can't help wondering what a fully DSP-corrected, tri-amplified version of this loudspeaker, with the high sensitivity coupled with optimized step and frequency responses, would sound like.—John Atkinson


Footnote 1: See the diagram at 14:40 in my lecture on loudspeaker measurements.

Footnote 2: See wikipedia.org/wiki/Precedence_effect.

Footnote 3: See villchurblog.com/inventing-the-speaker/ and www.stereophile.com/interviews/105villchur/index.html.

COMPANY INFO
Klipsch Group, Inc.
3502 Woodview Trace
Indianapolis, IN 46268
(317) 860-8100
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COMMENTS
Ortofan's picture

... the First Watt SIT-3 and the Quad II Classic.
https://www.stereophile.com/content/first-watt-sit-3-power-amplifier
https://www.stereophile.com/tubepoweramps/805quad/index.html

RTS13's picture

Definitely agree he should have tried Nelson Pass’s First Watt amps. Also, the reviewer doesn’t state which wall he had the horns on, but guessing from his comments bet they were on one of the short walls. Unfortunately for 99% of the people can’t rearrange their music rooms, but if he had tried them on the long wall and tight as possible in the corners and clean smooth walls on each side of the speaker of at least 4 feet, the sweet spot would have been 8-1/2 feet from the front wall. Having smooth full height walls adjacent to the speaker is paramount IMHO. That way he could have his seat away from the back wall helping with reflective sound screwing up the primary arrival of the music. I use Altec corner horns and the improvements in sound quality once I moved them to a long wall with full height smooth walls of 10 feet adjacent to each speaker was nothing short of Devine Intervention. And time alignment of the various drivers using a RTA is critical to ensuring a cohesive presentation. Just a thought.......

gcvanwinkle's picture

Many eons ago at a LA NAMM (National Association of Music Merchants) show I was listening to some pro Altec horns that were time aligned playing brass band music at serious SPLs. I turned to the guy next to me and saw that it was none other than Paul Klipsch! The Altec guys noticed Paul so they turned down the volume and motioned him closer as he obviously had some questions. After he left they cranked it up even louder as if to say to Paul "these are what horns are supposed to sound like!". Very impressive demo.

Needless to say, I too would love to see how the modern K-horns would measure properly DSP'd - but I would also like to request that John try to measure a vintage Klipschorn in good condition to see how that compares to the modern version.

jeffhenning's picture

He brought it up, but I said the same thing on a different sight about the Klipsch Forte.

They measured dynamic compression/linearity, frequency response and distortion. They were all very good, but they didn't measure temporal performance.

I expected the temporal performance of this speaker to be very poor and it is. That passive crossover (like all passive crossovers) severely handicaps the design.

Some serious DSP and tri-amping would help this beast out immensely.

There still seems to be some issues with the mid driver that need to be hashed out. The spectral plot shows a lot of break up above 4kHz. Also, the bass cabinet vibrations are a bit concerning as well.

Even so, if you bypassed the crossover and used a digital speaker processor and Dirac Live or DEQX or a Legacy Wavelet, a pair of Benchmark AHB-2 amps for the mids/highs and beefy class D mono blocks for the woofers, you would have a incredibly potent system for around $25K.

Not cheap, but it would outperform the most systems regardless of cost.

I'd love to see what measurements JA would get with an active, DSP'd Khorn.

JHL's picture

DSP is an immensely powerful tool, however its absence in no way conflates with any assertion that passive filters are inherently defective. Put another way, rendering this speaker flat in the amplitude domain is no guarantee that half a dozen key criteria - which are in effect why horns exist - would be improved, if even addressed.

Unless we grasp all aspects of loudspeaker behavior we can't begin to assert that DSP is the panacea armchair advocates claim.

jeffhenning's picture

You are making some inferences about my post that were not implied. So let me elaborate.

• While flat frequency response is preferable, it is not nearly as important as the ability to equalize the group delay and eliminate the phase distortions of a speaker. DSP can do that. Passive cannot.

• Once you have addressed the temporal issues with DSP, the remaining speaker and room related issues are much easier to address with EQ in DSP

• When you are talking about a speaker like the KHorn, the room is part of the equation for its sound. That's what makes it such a brilliant design. Instead of fighting the room acoustics, it works with it. The proviso being that the room has to sound good before you put the speakers in it.

• Passive speaker systems have very little left to offer in improvement. We've watched as the refinements in passive speakers that are affordable have made them really good in the last 40 years. We've also seen idiotic designs like that Wilson Chronosonic monstrosity that move nothing forward in the realm of speaker tech. I own KEF LS50's for my mains in my system. They are fantastic for what they are. Can they be improved upon? Sure. Will it be as great as their active, DSP'd siblings? I doubt it. KEF understands that and they know more about speaker design than anyone who writes here.

• Passive speakers, no matter how good they are, have serious flaws that can never be fixed without DSP. If you are some type of purist who wants to stay with obsolete technology, are you also willing to state that CRT screens and video tape are as good or better than Blu-rays and OLED? That analogy is valid.

• I think that a fully DSP'd, tri-amped KHorn would be awesome and I'd love to hear it after they also bolstered that front panel and got a better mid driver.

• Unfortunately, my basement theater can't accommodate KHorns because of the odd stairs and the weird shape of the room. Neither can my project studio in my dining room.

• A DSP'd, multi-amped KHorn would be mind blowing and further validate a truly great design that should be improved upon for future generations. This speaker's potential has not yet been fully exploited.

• Paul Klipsch was a genius, baby!

JHL's picture

Your points corrected, in order:

-If group delay and phase ever become reliably and commonly moored to sound the field will advance and DSP may cease being the conjectured wonder it is today. Until then assumptions about DSP vs analog filters naturally remain just such conjecture.

-Whether rooms are as critical as conventional wisdom assumes is another argument compounded by conflicts in Objectivist dogma. Whether DSP is easier is therefore moot. Whether it genuinely sounds better is not.

-Axiomatic, although fine horns in theoretically terrible rooms are much better than average speakers in very good rooms, which leads back to the current schizophrenia over speakers in rooms in general. As with measuring speakers, we'll have to solve how we feel about such things in a relative and meaningful sense before we can expect to progress.

-Passive speakers are hardly a comprehensively understood phenomenon, and they're even less a well-developed phenomenon in the casual eye, which casts doubt on the assumption they will automatically be surpassed by moving their filters into another type. Ignorance about real aspects of real things like the very large WMTMW you mention is proof of such assumptions. The same can be said of miniature coaxial speakers. Contrasting them poorly is absolute proof.

-All speakers have serious flaws. A meaningful hierarchy of those flaws - which doesn't exist yet - will naturally run in parallel to a meaningful hierarchy of their respective sound. It just won't replace it, which along with not speculating about either is a key truth.

-Me too. Migrate back up-thread and catch the mention of PK attending a proper horn setup. This is no small thing.

-Whether a DSP'd KHorn would blow the mind is unknown. Whether some would immediately grant it super-speaker status anyway is somewhat less in doubt.

-Fortunately others continue on, with excellent effect.

jeffhenning's picture

A dilettante has given me his dubious expert opinion.

I've now wasted enough bandwidth on this subject.

Have a nice life in your incomprehensibly understood world.

JHL's picture

Expending a small dictionary is one way to appeal for acclaim, but good audio really only asks for reasonable proofs of reasonable concepts. Those who can, do.

The fun part is that while one may simply observe the obvious, he gets to hear it too. I did and I do.

Bogolu Haranath's picture

Some of the listening impressions AD had with these K-horns, could have been due to the required corner placement of these speakers ........ If AD could have listened to the some what similar looking Klipsch La Scala AL5 speakers (reviewed recently by HI-Fi News), his listening impressions might have been different ....... La Scala AL5 don't require room corner placement ..... See also, Klipsch website :-) ........

Bogolu Haranath's picture

The K-horns have more demanding low impedance loads in the mid and upper bass region (see measurements) ....... The La Scala AL5 are not that demanding in this region as per Hi-Fi News measurements :-) .........

Bogolu Haranath's picture

Another choice, without using DSP could be, using SS amp(s) which can handle low impedance loads for bass frequency, and SET tube amp(s) for the mid and high frequencies :-) .........

Bogolu Haranath's picture

AD was trying to drive a fully loaded 18 wheeler Mack truck, with a four cylinder engine, so to speak :-) ........

Jim Austin's picture

Some of the listening impressions AD had with these K-horns, could have been due to the required corner placement of these speakers

As was made clear in the article via an extended quote, corner placement for the new K-horns is not required, according to the company.

Jim Austin, Editor
Stereophile

Bogolu Haranath's picture

May be Jim Austin can tell AD to keep the K-horns for a while, and send him some amps like darTZeel NHB-468 mono-blocs, McIntosh MC462 and may be even the new Parasound Halo JC-5, and tell us how they sound with the K-horns ....... AD could do some follow-up reviews :-) ........

Jim Austin's picture

Too late: Because we needed to take photos for the cover--and also because Art needed to return to his reference system in order to review other stuff, the Khorns were removed promptly and shipped out.

I too noticed that Hervé likes the La Scalas with his big amps (a review of which, by the way, is forthcoming). However, it seems from the measurements, to me at least, that when used with a low-impedance SS amp, the Khorns would be pretty hot. You can see this quite clearly in Fig.5 in the measurements, but it's implied in the impedance plot and is also quite clear fro Fig.4. I don't think the answer lies in using a typical SS amplifier. Rather, that might be the answer, but not by itself. After all, the only other answer is hit-or-miss matching with various tube amplifier impedance curves; try 'em until you find one you like.

This is just speculation, but I'm with those who say that this speaker probably still needs very tight corner placement (despite the new back panels and in contrast to the company's recommendations) and is best used in large rooms where you're mainly listening to the reverberant field. Isn't that how they're usually deployed?

Jim Austin, Editor
Stereophile

Bogolu Haranath's picture

Like you mentioned, the K-horns probably work better with big tube amps like Audio Research reference line or McIntosh tube amps :-) ......

Bogolu Haranath's picture

Since we are talking about tube amps, you could ask AD to review the new 70th anniversary McIntosh MC2152 tube amp ......... MC2152 looks gorgeous ........ Most likely it will sound gorgeous, as well :-) ..........

SpeakerScott's picture

See my comments elsewhere..you're interpretation of the manual is completely incorrect.
Quote:

The Klipschorn can now be toed in or out to obtain the best imaging.
The corner still serves as an extension of the low frequency horn,
improving low frequency performance. For best results, Klipsch highly
recommends the Klipschorn be placed in the proximity of a corner.

Jim Austin's picture
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SpeakerScott's picture

Seriously...you guys did not do a good job on this one.

I'll admit I posted in a way to get your attention...but.

The measurements do not remotely accurately show the low frequency performance of the speaker. You've got it wrong. Period.

AJ's picture

Me too. Said lightly.
Not a thing wrong with JA's quasi-anechoic measurements, as posited.

My only quibble would be the normalization he uses for lateral off axis. But that's not "wrong" either.

AJ Soundfield Audio

Bogolu Haranath's picture

Problem seems to be 'quasi-knowledge' of some of the commentators :-) .........

georgehifi's picture

Those measurements are not what you expect from a $15k speaker, good luck selling these Klipsch today at that price, back in the 50-60's maybe

johnny p.'s picture

..like the Volti Rival speaker. Sub-par test results, great sound, IF driven and set up right.

JA has a long history of (disconnected) test-results and sound.

John Atkinson's picture
johnny p. wrote:
JA has a long history of (disconnected) test-results and sound.

If you have read Robert Heinlein's "Stranger in a Strange Land," you will be familiar with the concept of a "Fair Witness" - someone who describes how things actually are. That is the case with the measurements that accompany the magazine's reviews. They describe what the product is actually doing regardless of whether or not the reviewer likes or dislikes the sound.

The question then becomes: is the reviewer's opinion of the sound due to the measured problems or despite them? To pretend that the measurements must somehow be flawed evades that question and serves no-one.

John Atkinson
Technical Editor, Stereophile

johnny p.'s picture

..there is no constant-correlation between tests and sound. (Many) wide gaps remain. The darTZeel amp -high distortion, best amp ever.

I brought this up at Audio Asylum in a thread called "Those darn measurements" about 2 years ago. And without my intention, posters there said you didn't measure the Volti Rival speaker correctly.

Audio Perfectionist mentioned your cherry-picking style of measuring many years ago.

So, if you're not doing it right OR the debate's been settled, why bother ? What are you trying to prove, decade after decade ?

Bogolu Haranath's picture

Well .... Let me try to defend JA1's various audio products' measurements ........ There are numerous products listed in the Stereophile magazine in the past and present, that measure well and also sound great ....... Most likely that trend will continue for many more years to come ........ Of course, there are going to be some products that don't measure well but can sound great ....... If I have to choose, I will choose those products that measure well and also sound great ........ Stereophile is one of the very few magazines that measures and also listens to the audio products :-) ..........

John Atkinson's picture
johnny p. wrote:
I brought this up at Audio Asylum in a thread called "Those darn measurements" about 2 years ago. And without my intention, posters there said you didn't measure the Volti Rival speaker correctly.

I read the thread. Yes, if someone liked a speaker that didn't measure well, they do say that the measurements weren't performed correctly. There was a comment that said that the Voltis should have had their in-room response measured. However, that wasn't possible.

John Atkinson
Technical Editor, Stereophile

JHL's picture

Given that a loudspeaker will exhibit a dozen key behaviors, its isolated amplitude response and related metrics naturally comprise an incomplete yardstick. This is an absolute surety. A loudspeaker is no more a plot than an automobile is.

Therefore, amplitude responses have without question become sighted bias. These threads of remarks are proof thereof.

This in no way excuses the potential for ham-fisted design, but it is also not the casual critic's claimed authority on good design. The authority on good design is sound, even as annoying as the human element has become of late.

To date Stereophile has done a good job separating hearing from the microphone. The distinction is as notable and important as is the *contrast* between sound and plot. I hope, for the sake of fine audio, that this remains the case. A loudspeaker simply cannot be snap-shotted like too many of us seem to want to believe.

johnny p.'s picture

..but possible to show sub-par results. Like Greg says below, "if you want a speaker that measures the way JA says it should, there are plenty".

In other words, good plots don't equal good sound. Or the reverse with horns, a popular speaker these days. God forbid you review Emerald Physics.

No distortion tests, no polar plots, no tone-bursts, no cavity-noise in db. And now more complaints at Asylum, in thread "Klipshorn's/Art Dudley".

With respect, it seems your goal for the last 30 years is to deceive and confuse, and that you have accomplished..

Bogolu Haranath's picture

As a side note ..... Emerald Physics top of the line speakers can be used with optional manufacturer supplied DSP/EQ/ crossovers ........ They also can be bi, tri and quad amped, and used with subwoofer(s), according to the manufacturer .......... See Emerald Physics website :-) .......

Anton's picture

Art found plenty of sonic issues, do we need to complain about that, too?

"If you want a speaker that sounds the way Art says it should, there are plenty..?"

John Atkinson's picture
johnny p. wrote:
No distortion tests, no polar plots . . .

Meaningful distortion plots are difficult without access to an anechoic chamber, as I have explained in the past. And no polar plots? You are perhaps unaware that every Stereophile loudspeaker review includes a full analysis of the speaker's horizontal and vertical dispersion, in a form that I feel is more informative than a polar plot.

johnny p. wrote:
With respect, it seems your goal for the last 30 years is to deceive and confuse, and that you have accomplished...

Apparently hell hath no fury like an audiophile whose speaker he likes the sound of is shown to have sub-optimal measured performance :-)

John Atkinson
Technical Editor, Stereophile

Bogolu Haranath's picture

".... to deceive and confuse" ......... Oh please JA1, don't run for public office ........ We need you here at Stereophile :-) .......

johnny p.'s picture

..don't do it at all. Why measure speakers in a driveway when it can have a VERY different response than a room ? Same for impedance, the Klipsch shows a scary drop, but is this what happens in a room ?

Toole/Keele/Geddes say that polar plots (or early-reflection directivity index) are important.

Where's the tone-bursts ? And how honest can it be to use (1) amp then blame the speaker ?

But tests are limited -no way to test depth of field, speed, coherence, instrument separation, coloration, etc.

People already struggle with understanding measurements and what you're doing causes controversy. The last thing we need here. (Try DARKO KIH #25 "what do measurements really tell us").

John Atkinson's picture
johnny p. wrote:
Why measure speakers in a driveway when it can have a VERY different response than a room?

It is universally accepted that anechoic or quasi-anechoic measurements are necessary to characterize what a loudspeaker does without it being influenced by the arbitrary and unknown room acoustics.

johnny p. wrote:
Same for impedance, the Klipsch shows a scary drop, but is this what happens in a room?

Yes.

johnny p. wrote:
Toole/Keele/Geddes say that polar plots (or early-reflection directivity index) are important.

As I said, rather than publish polar plots, I show in detail a loudspeaker's dispersion in both horizontal and vertical planes. This shows the same information as a polar plot in what I feel is a more easily comprehensible manner.

johnny p. wrote:
Where's the tone-bursts?

Every Stereophile loudspeaker review includes the measured step response.

johnny p. wrote:
And how honest can it be to use (1) amp then blame the speaker?

Please reread the measurements. You will note that although I used the same amplifier for this review as I do for all the magazine's speaker reviews, for consistency, I also used Art's Shindo amplifier for one test. Art himself used 3 amplifiers for his auditioning.

johnny p. wrote:
But tests are limited -no way to test depth of field, speed, coherence, instrument separation, coloration, etc.

That's why Stereophile's reviews include both measurements and auditioning comments. Neither on its own gives the full picture of a product's performance.

And FYI, you should check out the Hi-Fi News measurements of the Klipsch La Scala AL5 at www.hifinews.com/content/klipsch-la-scala-al5-loudspeaker-lab-report. Similar to my own findings with the AK6.

John Atkinson
Technical Editor, Stereophile

johnny p.'s picture

Using a second amp for only (1) test, then not renting the use of a semi-anechoic room. This is not science. If your readers think it is, then that's fine.

A step response is not the same as tone-burst or group delay. And for what you do measure, you gave up using a room with smoothing and averaging. Art's driveway, Mike's driveway, even simple science is gone !!

JHL's picture

Great audio has a long history of disconnected test-results and sound. The high end frontier is figuring out how and why.

Anton's picture

Wow, the body disappeared.

I had wondered whether the different amps Art used would have produced difference measurements in JA1's protocol.

It would be interesting to see if there was any correlation between what Art heard and what JA1 would measure.

Scintilla's picture

I had the same thought about using DSP-implemented crossovers as I read through the review and then John just nailed it. Apparently we are all beginning to not just accept the value of DSP in real-world implementations as being an outlier, but that it is becoming "normal." I would add to that though: shame on Klipsch for not seeing that themselves. In this age of cheap silicon and relatively mature off-the-shelfs, c'mon Klipsch, get with the damn program for a $15k speaker! At least offer an in-house designed and optimized optional unit. That's just a shameful lack of vision for such a storied company. What would Paul Klipsch say?

jmsent's picture

......Bullshit! He may have said that in this case. Face it, this is a 1950's era speaker and it shows. It was resurrected to appeal to people who remembered if fondly when it was current, but couldn't afford it. Klipsch already builds far superior speakers to this one, and I'm not all that convinced that a DSP crossover will propel this speaker into SOTA territory. There are inherent problems in the drivers and cabinet that DSP can't fix.

jimtavegia's picture

for telling it like it is, and explaining what a great solution might be. Regardless of the flaws, to me the one thing is that someone could drop serious money on this speaker and never know that their amp is not a great match for this new model. Now they at least know that the amp they use will matter greatly.

The other issue of time delay between units can be corrected and it would be good for Klipsch to be the ones to offer a box solution for their customers, but that is a marketing decision they will have to address.

I trust there are many owners who are not audiophiles who may be enjoying them regardless of the flaws as there are millions who are still content with MP3s and worse. They won't have the EQ problems solved, but to each his own. Now they know what the issues are if they are subscribers.

Still a beautiful product with a solution in sight. I hope someone had the ability to market it.

Ortofan's picture

... Roy Delgado - and, if it's still known, Paul Klipsch - used during the development of the Klipschorn.

kenkirk's picture

I visited the Hope Ark factory back in the early 70's as a teenager. I saw Paul in a sound room working. He was not a super friendly kind of guy. I was hoping to meet him. But I remember seeing the distinct blue faceplate and huge meters of McIntosh gear in the room. And they were playing. And one of the best stereo demos I have ever heard in my life was from a pair of Klipschhorns with a Belle Klipsch center channel driven by McIntosh tube amps, McIntosh preamp and a nice turntable of the day. I think it was a Dual.It was a stereo store in Texarkana Texas. I am sure Paul probably helped them set up the system as they were close to Hope. They played for me ZZtop La Grange at live levels. I will never forget the sound of the drums then the bass and guitar come in and just exploded. Goosebumps on goosebumps. Klipsch done right can be a window into live music. Just huge fun. I had Klipschorns for years. I moved on to Sonus Faber when heard a 3d soundstage from Extremas that just moved me in a different way. But still have a set of Hereseys for parties. :) Very cool Stereophile reviewed these speakers! Ken

Bogolu Haranath's picture

May be they were darTZeel NHB-468 mono-blocs for this latest version of K-horns ...... Who knows? ...... See AnalogPlanet's visit to darTZeel facility :-) ........

May be AD could borrow a pair of NHB-468s, and tell us how the K-horns and darTZeel sound together :-) .........

Bogolu Haranath's picture

Of course, it would be lot less expensive to use McIntosh MC462 (reviewed by Stereophile), if AD chooses to use it, for a follow-up review :-) .........

Bogolu Haranath's picture

Any amp(s) with the first two numbers 46 may work fine :-) ........

Ortofan's picture

.

Bogolu Haranath's picture

Volti Audio Vittora, reviewed by AD without measurements, looks very similar to Klipsch La Scala AL5 reviewed recently by Hi-Fi News :-) .........

georgehifi's picture

"If I have to choose, I will choose those products that measure well and also sound great ........ Stereophile is one of the very few magazines that measures and also listens to the audio products"

And that's the way all mags should be, not just the reviewers opinion.
After all any audio equipment is made with test measurements and ee calculations, if not, I wouldn't even spit on it, it'll be rubbish.

Cheers George

Lars Bo's picture

Thanks Art. What a gutsy conclusion. Thanks for telling it like it is.

Thanks John. Excellent, informative report. Thanks for telling it like it is.

If body, soul, and musicality were essentially to be found in a lab, things would be different. They're not. I'm not so sure this is a bad thing, really.

SpeakerScott's picture

First let me be clear..it's tough measuring a corner horn like this. But if you're going to do the review...and then publish these measurements....you've got to do better than what was published here.

1. The bass response shows the dramatic ripple associated with too small a mouth area. Keele's work on optimum mouth size (AES Convention 46, 1973, preprint available on his website) shows great examples of the ripple here. While Klipsch has added the back panels meaning the speaker doesn't have to be flush against the wall it still needs the corner loading to finish the horn flare. By measuring it in a driveway you've robbed it of a huge portion of it's bass In a perfect world if you found a large building exterior in the shape of an L and stuck the speaker in the corner you could maintain the flare, and then measured ground plane you would have gotten much closer to the actual capabilities of the speaker. While I understand the practicalities, this should be mentioned in the review.

2. The impedance of a horn speaker depends greatly on the horn loading....it's not clear in the review text if the impedance was measured in room or in the driveway. I suspect you'd have a different result if you measured it in room.

I can't help but suspect they would have significantly better results if they changed the horn flares to account for some of Geddes work on higher order mode creation. There are tractrix flairs available that have significantly better performance than the ones measured here. That would stay true to Paul's desire for good acoustical matching while maintaining better wavefront propagation in the horn resulting in fewer internal reflections and the ragged response shown.

Scott

Anton's picture

Thanks for posting that.

Volti's picture

I think JA's testing of the Rivals was pretty much spot on, and looked very much like my own tests. I suspect his testing of the Khorn was also pretty well done, although one would think that a speaker designed to be in a corner should also be tested in one.

I could easily modify the design of the Rival speaker to test better, and it would change the sound of the speaker if I did that. I like the way they sound, and it's not worth it to me to change that sound so that the measurements look better. There are choices I made during the development of the Rival, and the sound I wanted took precedence over the measurements.

Not one single Rival customer would have me tweak the design of their speakers and therefore change the sound, in order for them to test better.

Many of the tests used to test loudspeakers have baselines that are subjectively derived. Someone, at some time in the past, said that a speaker should be more or less flat in frequency response across the bandwidth to be considered "correct". That's a subjective evaluation.

If you want speakers that measure the way JA and others say a speaker should measure, then go buy some. There are plenty of them out there, new and used. Khorns are not that speaker.

All this talk of DSP and tri-amping to change the Khorn into something it is not just seems foolish to me. I would no more try to make a big horn speaker sound like a Tidal/Wilson/Sonus Faber/Magico speaker than I would try to make a Tidal/Wilson/Sonus Faber/Magico speaker sound like a big horn speaker. They are two entirely different things, and if one doesn't suit your tastes, you should buy something different.

Life is too short to messing around with DSP and tri-amping. All that complication does is make you focus more on the equipment and less on the music. Keep it simple. Have Fun!

Greg

Jim Austin's picture

It raises several interesting questions, but I'll exercise restraint and keep this reasonably short. First, though, I'll mention that according to the manufacturer, the new K-horn does not require corner placement. Here's the language from the manual: "The Klipschorn (AK6) has a fully enclosed low frequency horn and no longer has to be flush to the corner in order to operate properly. The Klipschorn can now be toed in or out to obtain the best imaging. The corner still serves as an extension of the low frequency horn, improving low frequency performance. For best results, Klipsch highly recommends the Klipschorn be placed in the proximity of a corner." This is precisely what Art did.

Now for the question--I'll limit myself to one. Are you willing to share an example of a specific design choice you made that resulted in worse measurements and better sound? Please don't read skepticism into this, and don't assume it's some kind of loaded question--it's not. I'm merely curious, and I think it would be interesting to others as well.

Quick anecdote: A few months ago, I was with John Atkinson. We were chatting just after hearing a demo of an excellent, modestly priced loudspeaker. I said to him, "It seems to me that the problem of designing a classically well-behaved loudspeaker is basically solved." With heavy MDF cabinets and good engineering, you can have a resonance-free enclosure and excellent frequency response on and off-axis. (I'm talking about frequency-domain; adding in time-domain challenges further complicates things.) And here I'm not assuming any use of dsp. If my observation is correct, then the frontier moves either to fine-tuning--raising the bar on classical performance--or in designing interesting alternatives to the "classic" design.

To be clear, by "classical" I mean not traditional but orthodox from an engineering standpoint: resonance-free enclosures, even, flat frequency response, uniform dispersion, etc.

My Best,

Jim Austin, Editor
Stereophile

Ortofan's picture

... that a heavy resonance-free cabinet was unnecessary if the resonances were relatively low in frequency and amplitude such that they would be masked by the program(me) material?
A few British speaker makers still employ that lossy-jointed, thin (and damped) wall concept of cabinet design.

Jim Austin's picture

That's one approach to speaker design that has stood the test of time, but the "classical" approach I'm referring to is more Floyd Toole.

Jim Austin, Editor
Stereophile

JHL's picture

The constant power, uniform directivity philosophy, coupled with the standard approach to lowering resonance and hopefully distortion, has delivered many a nicely theoretical loudspeaker. Many sound pleasant enough, as they should. There's no evident reason not to seek that goal.

This is because they're roughly the equivalent of raising the automotive bar by way of the onboard computer - instant EFI, timing curves, boost and traction control, and even racer telemetry if you like. Who wouldn't want that; it's all for the good.

And indeed the industry is presently enamored by the average speaker's equivalent of onboard computing in an era when so many speakers are average. The problem arises when everything it appears in ranges only between Toyota and Lexus. There are no outliers, few exceptional exceptions, and especially, less consideration given to all available technology.

Like speakers, this is also fine for cars: We all more or less drive standard transportation (even though we bench-race everything but). We can't be questioned when we listen to $1000 production loudspeakers, even when they run a few times as much. It's the current thing.

Yet for speakers there is an alternative to that school, and it doesn't hinge on brief demos of Accords vs Corollas to teams of amateur listeners in an office park.

Combing the experience of audio pros reveals and confirms that historical audiophile preference has indeed identified good-sounding speakers and for very specific reasons, and not the current trend of what they do in directions other than at the listener. There's a good reason the experienced audiophile prefers what s/he prefers and statistically the audio pro with his decades of hearing agrees.

The speaker field hasn't been entirely well-served by the so-called science of how uniformly the average, frequency-centric speaker energizes a room specifically suited to it. It has, however, been well-served by seeing speakers as transient energy devices, which is how music manifests.

Bogolu Haranath's picture

May be Ortofan likes all those 'Good Vibrations' :-) ...........

Bogolu Haranath's picture

Next thing Ortofan is gonna say is, those 'damping rings' around the vacuum tubes are not gonna make any difference :-) ........

Bogolu Haranath's picture

Well ...... Speaker cabinet vibrations and vacuum tube vibrations are not the same thing, not the same principle :-) ........

Anton's picture

Please don't get yourself too worked up.

Bogolu Haranath's picture

The other Bogolu is my evil twin :-) ........

johnny p.'s picture

...someone got it right, the new editor of Stereophile, no less.

And maybe we're close to a new paradigm. We only lack the light to show us the way...

AJ's picture
Quote:

Are you willing to share an example of a specific design choice you made that resulted in worse measurements and better sound?

Hmmm, popcorn ready, I'll be waiting for this answer myself! ;-).
I see that fable often on audiophile chat sites "measures good sound bad, measures bad sound good". But when asked to cite a single example with comprehensive measurements, either total silencce or "because I said/claim so". Of course, that is often sufficent "evidence" for the claimants. Their primary consultant on electro-acoustic/perceptual science is themselves, because they have very good brains and have said a lot of things ;-).

cheers,

AJ Soundfield Audio

p.s. guilty as charged being a dsp triamp time waster!!
I could design a passive crossover for luddites in my sleep, but alas...

timbo69's picture

i was a subscriber from 1983-1999,went to 2 Stereophile shows(Santa Monica 1st & San Francisco) K-horn owners were always asking for a review,but JGH&J.A. weren't for it.I bought my Pair in 1983 for 2383.00 tax included.Thanks Art(I know u weren't with the magazine back then)for FINALLY doing the review,BTW wish u had tried with solid state amp or av receiver.that's where the BASS is

Robin Landseadel's picture

Back in the mid-90's, I hung out with a man who installed custom audio systems, had bulk Van den Hul solid-core interconnect. I managed to use some for internal re-wiring of some vintage gear. Another friend gave me a Marantz 8b. I was never all that happy with the amp, the dude with the wire [sorry, can't recall his name, he lived in Berkeley and wasn't Ric Schultz, another 'wirehead'] happened to have a pair of Kilpschorns in an [tiny] acoustically inappropriate room. If you wanted to hear the lower octaves, you had to go to the next room. In any case, he wound up with the Marantz 8b. I still heard everything I didn't like about the amp, but it worked better with the Klipschorns than any thing else on hand to hook up to the horns. I get the feeling that Klipsch speakers want a lot of room. Like maybe a motion picture theater. I think earlier remarks concerning room reinforcement to be pretty on point, and I'd add that the lowest octaves for this speaker really need a big room. I wonder how a minty Marantz 8b would work out with the updated Klipschorn?

There was a shop in Ferndale California, really beautiful all-wood construction, probably built in the early 1900's. The ceiling was two stories high, the floor-plan was open, about 30 feet wide by 50 feet deep. This store had Heresys mounted 12 feet up, made a glorious sound in that room. Not a lot of bass, but everything else was right in place.

I managed to find a pair of bookshelf Klipsch speakers from the 1990s at a yard sale, $15 for the pair. leaner than usual on the bottom but more dynamic than than anything else in the house. There were a lot of speakers to be found at these yard sales, also found Paradigm Titans and a/d/s L400's, but the Klipsch speakers were easily the most dynamic of the bunch.

As it turns out, Klipsch makes my favorite earbuds. The MRSP for the X11i earbuds is $350, BLINQ had them for closer to $100. These are the smallest earbuds I have encountered, designed to go further down the ear canal than typical, with tiny and lightweight drivers. Sound is wide-range and very detailed, possessing nothing like what I would call the Klipsch "House Sound". I find it ironic that the company that produces these monster horn speakers makes tiny, audiophile earbuds.

Anton's picture

Regarding the amps sounding so different...perhaps the screws on the cases were set too tight or too loose?

Jonathan Scull noticed that back in the day, as well! I forget which amp, I think it was a big beast with 17 screws on top?

Bogolu Haranath's picture

Was it 'screw loose'? :-) ........

Anton's picture

Eeerily similar to a J-10 review from the foggy past!

Bogolu Haranath's picture

AD screwed-up many audiophile minds, now ....... They are gonna mess around with screws for several weeks and months from now on :-) .........

Bogolu Haranath's picture

Next thing we know AD is gonna write another listening article, telling us how a brand new set of screws he got from Home Depot, made in a Far East Asian nation, worked best :-) .......

Glotz's picture

and his funky chair and lover?

Great writer...

John Atkinson's picture
Glotz wrote:
Great writer...

Yes, J-10 was and still is a great writer. He left the magazine's staff in 2003 and joined Monster Cable, working in marketing. He credits Noel Lee for a business education and left Monster a few years later to set up his own PR company, Scull Communications, which is still ongoing. Many of his reviews and articles can be found on this website at www.stereophile.com/writer/91.

John Atkinson
Technical Editor, Stereophile

Bogolu Haranath's picture

May be J-10 could review the new Synergistic Research $10,000 'World's reference power cable' for Stereophile? ........ See J-10 article interview with Synergistic Research founder, Ted Denny in Stereophile ....... Also, see page 64 print edition of Stereophile, Sep. 2019 issue :-) ........

Bogolu Haranath's picture

We miss those J-10's automobile sound systems reviews ......... May be Stereophile could bring them back? ........ Some of the latest auto sound systems sound really good ......... Some of the hi-end audio designers are designing the latest versions :-) .........

Bogolu Haranath's picture

JA1 could make many, many road trips to AD's place for measurements, driving some of those automobiles with hi-end audio systems :-) .......

Bogolu Haranath's picture

JA1 could start with the new Rolls-Royce Wraith and the new mid-engine Corvette Stingray :-) ........

Anton's picture

Regarding speakers, especially horn speakers, we are likely all familiar with how people talk about being far enough away when listening to allow for better "driver integration," where sounds no longer seem to becoming from drivers that can be spaced pretty far apart.

I think Art and JA, and Mike Fremer in his recent impressions from listening at, was it darTZeel? all landed with noting problems with timing issues. (But they all seemed like rather near field listening experience for this big ass speaker!) I agree with the person above who was suspicious about Art's room size (no matter that Klipsch 'approved') being to small to let the timing issues integrate more favorably. These really aren't, to me, small room speakers. In a big room, the timing issues are masked by the room reflections, etc.

Also, despite the speakers no longer 'needing' a corner...it's pretty obvious that a real corner will extend their predicted bass boundary to a greater extent than a nailed on baffle does. perhaps some accessory wings to expand the new artificial corner the back baffle provides would go a long way to improving the new sonics.

I say all this as a Klipsch lover - I have a pair of heresy and a pair of La Scala speakers and they are lovely.

Tesla one's picture

One paragraph from Mr. Atkinson's measurement section interests me in particular:

Quote:

I wasn't too surprised by the Klipschorn's limited low-frequency extension despite its size. I was reminded of the impact Acoustic Research's first loudspeaker, with its relatively small sealed enclosure and "acoustic suspension" woofer, made in the mid-1950s. "My measurements showed that my little prototype had better bass and less distortion than anything on the market, yet it was one quarter the size," wrote AR's founder, Edgar Villchur, adding "I thought, 'This has got to be the future of loudspeakers.'" (footnote 3) It was.

It's surprising as it isn't to see JA effectively siding with Mr. Villchur's statements, when the latter is the man promoting his own invention to cater to buyers who're mostly concerned with size and looks. Going on to further claim sonic superiority from a 1/4 size package with low sensitivity is really wanting to have your cake and eat it too. There's no denying the success Mr. Villchur's design spurred for years to come, in that regard certainly the future of loudspeakers, but what's the benchmark here? Realistic sound reproduction, or certainly its approximation hinges on physics of which size, sensitivity and ease are core parameters, and I don't see any of those apply to the AR1 and its same-principle descendants. My gripe with JA (and Mr. Austin) on this is that he fails to realize a smaller, low(er) efficiency and direct radiating speaker isn't an exhaustive reference in and by itself (well-behaved it may measure - "well-behaved" being the operative word here), but a different principle with its own set of compromises.

In all fairness I believe Mr. Atkinson's closing remarks on DSP-compatibility with the K-horn is a constructive approach, but as Greg of Volti Audio pointed out it also takes away "the juice" of what really defines these speakers and has for over 70(!) years now. It's not that I don't welcome improvements made to a design; my own speakers are exactly that of the Klipsch Belle.

davidrmoran's picture

>> what's the benchmark here? Realistic sound reproduction, or certainly its approximation hinges on physics of which size, sensitivity and ease are core parameters, and I don't see any of those apply to the AR1 and its same-principle descendants.

Well, come on, if the benchmark is realism of sound reproduction below ~50Hz, then there are no contest and no discussion --- the AR1 and its many descendants (waning in these recent decades of vented-design ascendancy) have achieved with ease where Klipschorns fail, for every minute of those 70 years.

m_ms's picture
Quote:

Well, come on, if the benchmark is realism of sound reproduction below ~50Hz, then there are no contest and no discussion --- the AR1 and its many descendants (waning in these recent decades of vented-design ascendancy) have achieved with ease where Klipschorns fail, for every minute of those 70 years.

Tesla one here, under a new name.

I Don't know exactly what aspect of sub 50Hz you're addressing here (other than "realism," but more on that later), whether it's the overall nature of bass reproduction and/or whether it concerns the Klipschorn's hardly extending down that low (it seems their "hard deck" sits at some 35-40Hz). In any case the aim with my comment, now some time ago, was to fire a bit more broadly than the Khorns themselves, but perhaps redirecting the attention to the quoted section above by Mr. Atkinson may clarify:

Quote:

I wasn't too surprised by the Klipschorn's limited low-frequency extension despite its size. I was reminded of the impact Acoustic Research's first loudspeaker, with its relatively small sealed enclosure and "acoustic suspension" woofer, made in the mid-1950s. "My measurements showed that my little prototype had better bass and less distortion than anything on the market, yet it was one quarter the size," wrote AR's founder, Edgar Villchur, adding "I thought, 'This has got to be the future of loudspeakers.'" (footnote 3) It was.

I then pointed out a problematic issue, seeing:

"... JA effectively siding with Mr. Villchur's statements, when the latter is the man promoting his own invention to cater to buyers who're mostly concerned with size and looks. Going on to further claim sonic superiority from a 1/4 size package with low sensitivity is really wanting to have your cake and eat it too."

Mr. Villchur simply referred to measurements of his own design and invention implicating (in effect) a perceived sonic advantage, something I believe is quite dubious. The Khorns may run out of extension below 35-40Hz, which is what you're facing when dealing with a "only-so-big" 1/4 wave horn, but for what it does its 15" driver, horn-loaded at that, will have to move much less than a smaller direct radiating, say, 8" woofer to attain the same SPL at a given frequency. That is to say: a bigger air radiation area and much higher efficiency equates into less cone movement and lower distortion.

A.W. set out to achieve comparable extension in a much smaller package, and in that regard he certainly succeeded while at the same time complying with the needs of costumers wanting for more decor "friendly" (i.e.: physically less intrusive) speakers. When you stress "realism" in your reply, however, I can only assume your understanding of it radically deviates from my own. Realism, as it applies to <50Hz, to my ears has to do with total ease at any SPL, as well as smoothness (an indication of low distortion), visceral impact and being fully enveloped. Smaller direct radiating designs simply won't you there, end of story. Below the Schroeder frequency in particular added quantity lends itself to bigger headroom and thus higher quality via lower distortion; that's approximating realism here.

It's worth considering the Khorns as a speaker model have gone on essentially unchanged for over 7 decades, still being produced, purchased and enjoyed by people around the world - despite them being restricted where LFE goes, and yet being relatively big and rather costly speakers. If the rationale would have been so obvious to dismiss them for "every minute" of their prodigious +70 year lifetime based on their supposed shortcomings, I'm sure many would have had ample opportunity to do so. And yet, history speaks for itself.

davidrmoran's picture

Yeah, this has always been the standard response --- look at how big and sensitive our product is, their cone movement, yada yada. (You actually do not want to get into matters of distortion.)
Of course I was speaking only of the ability to hit the air and make the VLF wave, period. Klipsches have never been able to do it, their long sales history notwithstanding, while large-diameter sealed woofers have, with ease and no strain, given enough wattage, since day 1.

m_ms's picture
Quote:

Yeah, this has always been the standard response --- look at how big and sensitive our product is, their cone movement, yada yada. (You actually do not want to get into matters of distortion.)

It came as a shock to me when I just found out Art Dudley - who penned the review of the Khorns for Stereophile, now published almost exactly 8 months ago - had passed today around the same time I wrote my reply to you. In his own words:

Quote:

In the years since the Klipschorn's debut, loudspeaker technology has progressed in many ways. Speakers that sound timbrally neutral and uncolored are much more common today, as are speakers with consistent and effective dispersion across their operating range. Thanks to the pioneering work of people like Jon Dahlquist, Jim Thiel, Richard Vandersteen, and John Fuselier (footnote 2), physical time alignment of drivers in a dynamic loudspeaker system is virtually a given these days, and the problem of baffle edge diffraction has been identified and smacked upside the head. The result is a great selection of loudspeakers that offer apparently flat frequency response, superb stereo imaging, and great airiness and transparency.

And what did we give up to gain such easy access to all those things? Natural-sounding dynamics. Impact. Pluck. Snap. Body—especially body. And soul.

And, I would like to add that the Khorns aren't wholly representative of the bigger, more sensitive segment of speakers. Much of what has been learned in the years since the Khorns "inception" back in the 40's is integrated in newer horn designs that need not comply with a vintage approach, and that truly gives you more of the ability to have your cake as well as eating it too.

Quote:

Of course I was speaking only of the ability to hit the air and make the VLF wave, period. Klipsches have never been able to do it, their long sales history notwithstanding, while large-diameter sealed woofers have, with ease and no strain, given enough wattage, since day 1.

Was it ever a desire of theirs in the first place to make speakers creating the "VLF wave"? They aimed at high efficiency and the sonic advantages this brought with it, and given the popularity these speakers gained over time, and still do, it would seem many were happy with the tradeoffs that followed here. And that's just the word: tradeoff, the one term that Mr. Villchur wouldn't admit to with his invention.

Indeed, why go picking on someone who never really intended to play the VLF-play you so desire? Myself I've picked the tapped horn route for 20Hz extension, but extension in and by itself is actually quite easy; I could have picked a pair or more of sealed or ported large-diameter woofers, again at about 1/4 the size, and be done with it - been there done that. But hey, it seems fruitless trying to explain to you why I've chosen the route that I have..

davidrmoran's picture

No, that's cool, you go, your route, and you be you. The claims for K-horns, if you were there at the start, did include all sorts of things that dropped by the wayside.

Whatever.

The Dudley quote is mostly as half-baked or uninformed as everything else he wrote about loudspeakers. Physical time alignment is as good comic prattle as natural-sounding dynamics, pluck, and snap.

Bogolu Haranath's picture

Just another suggestion ......... One or two powered subwoofer(s) could be considered for use with the K-horns ....... The crossover with the subwoofer(s) could be set at 100-150 Hz ......... In that situation tube amp(s) could be used for the mid and high frequencies ....... Those mid and high frequencies would be easier loads for the tube amp(s) .........That configuration also allows for more flexible room placement for the K-horns .......... See Stereophile review of Volti Audio Vittora for example :-) ..........

Bogolu Haranath's picture

The above mentioned configuration could also be used for the Klipsch La Scala AL5 ....... La Scala AL5 was reviewed with measurements by Hi-Fi News :-) ........

Anton's picture

A pair of La Scala speakers mated to a pair of SVS woofers is a thing to behold!

m_ms's picture

With the La Scala's I'd mate them a pair of horn subs - the operative word with this combo being integration! Tapped horns in particular I find to be very successful augmenting the folded bass horn of the Klipsch's. I previously used an SVS SB16-Ultra with my Uccello's (derived from the Klipsch Belle), and shifting to a pair tapped horns has been bliss ever since.

Anton's picture

What brands are there?

Bogolu Haranath's picture

Google search shows ... Cerwin-Vega, Peavey, JBL, Turbosound and few others :-) ............

m_ms's picture

Sorry for the late reply.

If we're talking tapped horns, non-DIY, there's really only Danley Sound Labs being they have patented the topology (if I'm not incorrect). Items of interest here (i.e.: being capable of hitting at least 25Hz) may be the TH50, DTS10 & 20 and THSpud. Of these may favorite would be the TH50. If you're willing to sacrifice extension in exchange for sensitivity there's also the TH118, which is good for some 30-35Hz. Remember tapped horns are bandwidth limited in their upper range, and usually only span about ~2 1/2 octaves cleanly. Personally I wouldn't go with a tune below 20Hz (which is rare anyway, and leads to monstrous-size cabs).

Tom Danley of DSL has given the DIY-community more or less carte blanche to develope their own tapped horns, and there are a range of designs here that are freely shared by developers like "lilmike" and Josh Ricci (look over at databass.com) for others to build. Myself I'm using a pair of lilmike's MicroWrecker tapped horns, and had a cabinet maker build the enclosures. There's money to be saved with DIY, and finding the right design from named individuals is a great way to go with this segment of subs.

The more classic Front Loaded Horns - again, non-DIY - could be the JTR Orbit Shifter LFU. Add to that a range of DIY-solutions like lilmike's Cinema F20 and Bill Fitz Maurice's THT.

Augmenting the La Scala's I'd also look into a design be Josh Ricci called the Skram. It's not a horn per se, but a variant of a 6th order bandpass which has a short horn-loading on the front side of the driver, and is ported on the backside. It uses a 21" driver, and there quite a few brands/models that fits this design, all of them typically fitted with neodymiun magnets and a very high power handling.

Horns, tapped horns, FLH's and 6th order bandpass iterations typically with pro drivers from 15-21" - all of this may seem like madness in a domestic environment (and believe me, potentially it is), but truly this is about the best quality bass reproduction that can be had, and subs that integrates the best way with the mains - including not least high sensitivity designs like the La Scala. Pro bass drivers are just snappier, more alive and tuneful in a proper designed and build enclosure - ultimately indeed more musical. The operating words here are ease, ultra-low distortion (for bass reproduction) - even at close to full chat, and room-filling envelopment.

m_ms's picture

Sorry for the late reply.

If we're talking tapped horns, non-DIY, there's really only Danley Sound Labs being they have patented the topology (if I'm not incorrect). Items of interest here (i.e.: being capable of hitting at least 25Hz) may be the TH50, DTS10 & 20 and THSpud. Of these may favorite would be the TH50. If you're willing to sacrifice extension in exchange for sensitivity there's also the TH118, which is good for some 30-35Hz. Remember tapped horns are bandwidth limited in their upper range, and usually only span about ~2 1/2 octaves cleanly. Personally I wouldn't go with a tune below 20Hz (which is rare anyway, and leads to monstrous-size cabs).

Tom Danley of DSL has given the DIY-community more or less carte blanche to develope their own tapped horns, and there are a range of designs here that are freely shared by developers like "lilmike" and Josh Ricci (look over at databass.com) for others to build. Myself I'm using a pair of lilmike's MicroWrecker tapped horns, and had a cabinet maker build the enclosures. There's money to be saved with DIY, and finding the right design from named individuals is a great way to go with this segment of subs.

The more classic Front Loaded Horns - again, non-DIY - could be the JTR Orbit Shifter LFU. Add to that a range of DIY-solutions like lilmike's Cinema F20 and Bill Fitz Maurice's THT.

Augmenting the La Scala's I'd also look into a design be Josh Ricci called the Skram. It's not a horn per se, but a variant of a 6th order bandpass which has a short horn-loading on the front side of the driver, and is ported on the backside. It uses a 21" driver, and there quite a few brands/models that fits this design, all of them typically fitted with neodymiun magnets and a very high power handling.

Horns, tapped horns, FLH's and 6th order bandpass iterations typically with pro drivers from 15-21" - all of this may seem like madness in a domestic environment (and believe me, potentially it is), but truly this is about the best quality bass reproduction that can be had, and subs that integrates the best way with the mains - including not least high sensitivity designs like the La Scala. Pro bass drivers are just snappier, more alive and tuneful in a proper designed and build enclosure - ultimately indeed more musical. The operating words here are ease, ultra-low distortion (for bass reproduction) - even at close to full chat, and room-filling envelopment.

Ortofan's picture

... wretched excess with horn loaded speakers might best be defined by the home system of Richard Burwen:
http://www.burwenaudio.com/Sound_System.html

Now there's a system that could well and truly blow the mind of the Audiophiliac. If it still exists, perhaps HR and/or AD could arrange to have a listen to it. Wonder what JA1's measurements would show?

Bogolu Haranath's picture

Check out Danley Sound Labs tapped horn loudspeaker systems (mentioned above) ........ Check-out their Jericho systems J1 .......... There are some videos posted on-line as well :-) ...........

John Atkinson's picture
Ortofan wrote:
... wretched excess with horn loaded speakers might best be defined by the home system of Richard Burwen: www.burwenaudio.com/Sound_System.html.

Wow. Just wow! I visited an audiophile in Tokyo in 1979, who had converted one end of his ground-floor listening room into the mouths of two enormous bass horns, with the drivers and the throats of the horns 2 storeys higher in his attic. But that fades in comparison with Dick Burwen's system!

John Atkinson
Technical Editor, Stereophile

Bogolu Haranath's picture

Wonder how "Money" by Pink Floyd in surround sound would sound like in that Burwen's audio system? :-) ..........

m_ms's picture

Indeed a staggering horn setup by Mr. Burwen. I also love the whole wall-console of mostly vintage-looking gear with its many knobs and VU-meters. Impressive. I'm assuming it sounds awesome, but surely, would it hold up to Mr. Atkinson's measured scrutiny? My guess: in this case, probably yes.

Apropos before mentioned madness or "wretched excess": overkill to some is just an approximation to sufficient headroom to others. Many automatically assumes that when an all-horn setup (or any other big, high-SPL capable ditto, which typically ends up being horn-loaded anyway) can potentially challenge the structural integrity of a house/apartment, then that's its sole or most "profound" purpose. I find this to be a simplified and prejudiced assessment that doesn't take into account the qualities that can be inherent to this segment of speakers, and the positive effect more-than-you-need can have. For example, to my ears a quality implemented all-horn setup has an attentiveness and "ignition" at lower volumes (i.e.: below 65-70dB's) that I find most low(er) sensitivity direct radiating speakers can't quite muster, and when you add in their overall impact, ease and cleanliness at very high SPL's it's dynamically a rather complete package.

How much headroom is necessary, one may ask, if it's even ground covered by most audiophiles in the pursuit of high fidelity? Realistic dynamics can be scary in their perceived impact, and daunting in regards to the requirements of one's reproduction gear - including amplifier power. Enough headroom - again, if it's even considered - to my mind should be no less than 10-15dB's of the maximum SPL one achieves during playback, preferably more. With bass reproduction I find it's even more important with headroom.

Bogolu Haranath's picture

Effort-less sound and effort-less dynamics ..... just like in real life :-) .........

Ortofan's picture

... there was an example posted to another site of a music clip with an apparent difference between peak and average levels of approximately 22dB. In order to reproduce those peaks without clipping, one's amplifier would need to be capable of a peak power output about 160 times higher than that required for the average listening level.

Bogolu Haranath's picture

Easy solution ....... We can get one of those pro quality compressors/limiters under $1,000, available at Sweetwater, and compress/limit the heck out of those nasty dynamic peaks :-) ........

Bogolu Haranath's picture

If somebody keeps playing 'one of the greatest albums of all time, Yeezus', over and over again on such a system as Burwen's, certainly 'madness in a domestic environment' could ensue ....... See AnalogPlanet :-) ........

..... which could lead to 'Summertime Sadness' :-) ..........

Ortofan's picture

... 'Summertime Blues'.
https://www.youtube.com/watch?v=MeWC59FJqGc

Bogolu Haranath's picture

In that case, "Nervous Breakdown" can happen :-) .........

Bogolu Haranath's picture

We were waiting for you to be the 100th commentator on this Klipschorn forum, Ortofan :-) ......

Bogolu Haranath's picture

Read, Ken Pohlmann's article 'Are you a watch guy?' in the Aug/Sep 2019 issue of S&V magazine ...... You may find some similarities :-) ........

tonykaz's picture

I took them in on Trade.

They are Gigantic, heavy, more powerful than a Diesel Locomotive ( even with a 40 watt. Tube Amp ). Phew !

They're toooooooo much for any Audiophile's listening room, bet they need 2,000 square feet with 30 foot ceilings. Pro-Audio guys use this type of folded Woofer in their 250 lb. Bass Bins.

After owning K-horns, owing Quad 63s seemed an ideal relief. Phew !!!!

Klipsch Quality is 100%

Klipsch Re-Sale value is very good

Klipsch Audio quality is Stunning, staggering even beautiful.

Buy Klipsch to match Room size then brace yourself for Hockey Arena SPL capability.

Every Man Friend will think that You own the finest loudspeakers ever made, every person in your neighborhood will know that you own them and know when you sell them.

You gotta own Klipsch at least once before you die, the people in Arkansas still make them right there in Hope and still answer the dam Phone when YOU call !!! ( god bless em )

Klipsch is an Experience , nearly indescribable with words.

Tony in the Tropics

ps. I'm hunting for a used pair of smaller Klipsch : Hersey, Cornwall, Forte ( the smaller, the better )

BillAllen's picture

Nothing wrong with these speakers, mine sound fantastic driven by a pair of Western Electric 91B amps.

Paul Klipsch nailed the issue 70 years ago ... "What the world needs is a good 5-watt amplifier."

Amen Brother!

Volti's picture

Sorry Jim, I wasn't paying attention to the comment section and just now saw your post.

I don't try for bad measurements and good sound, I try for good measurements and good sound. However, the sound I'm after (what I call good sound) and good measurements often diverge at some point in the development process, and I'll always let measurements go where they go in favor of the sound I'm after.

I'll give you a couple of examples of divergent agendas. :) I could easily make the Rival cabinet (which is very stoutly built with 1" thick Baltic Birch plywood, braced, and damped) not resonate as much as JA revealed in his measurements. In fact I built just such a cabinet and I was shocked at how 'dead' the music sounded compared to the final cabinet which has less bracing and damping. There are speaker designers who design and build speakers (that many customers love) with solid hardwood, rather than plywood or MDF, because that's the sound they are after, resonances and all. If a person wants a speaker with little to no resonances, they should buy one. There are plenty of them out there to choose from.

I could easily make a Rival speaker have flatter frequency response. In fact all Rival owners could do the same thing by simply increasing the output of the midrange horn to match the output of the woofer and tweeter. One or two might try it, but they won't leave it there.

The first prototypes of the Rival had a flatter response in the bass. I had to 'create' the sound of the bass that I wanted through driver/cabinet/crossover work, and that resulted in a test that showed less than flat response. JA revealed that in his testing as well. Flatten out the bass of the Rival? Ask any of my customers if they want me to do that for them. I'll provide email addresses for you if you'd like. Not being snarky here - I'm confident none of my customers would change a thing. If a person wants a speaker with a flatter frequency response, they should go buy one. There are plenty of them out there to choose from.

Back to the Khorns.

I tri-amped and digitally time-aligned my own Khorns back in 2009 and I quite enjoyed it for a while. The time-alignment was a noticeable improvement. But the complexity of the system took something away that I missed and I went back to passive crossovers and a really nice tube amplifier and a simpler system and I enjoyed that a lot more.

I also bi-amped with a solid state amp on the bass horns and a tube amplifier on the upper horns (passive between the mid and tweeter). That didn't work so well. In addition to the complexity of the system, I found that the balance between the two very different amplifiers changed slightly as I turned the overall system volume up and down. It just didn't work for me.

Khorns need to be in corners. I've restored several pairs of Khorns where I added backs and bracing to enclose the bass horns (I have webpages showing the restoration process). It is a significant improvement to the tightness and control of the bass, as well as the definition and musicality of the upper bass (low midrange). I found that I liked them best when tight in the corners, and less for every little bit I moved them out of the corners.

If you really want to hear what the very best Khorns sound like, you'll need to hear some that have the full compliment of Volti Audio Klipsch Upgrades in them. Far more impressive than anything that can be done with DSP, Tri-amping, time-alignment, etc...

Greg

Art Dudley's picture
For its wisdom, candor, and sheer generosity, this post deserves to be at the top of the page. Thanks, Greg :-)
Ric Schultz's picture

I heard K-horns in Berkeley years ago at the Stereo Workshop on College ave....back in the late 70s. He had an unfinished pair nude with xovers sitting out where you can see them. The tweeters were remounted all the way in the back of the speaker right above the midrange compression driver to time align the mids and highs. We A/Bed the modded speaker with Quads....very little difference.....really! Roger, the owner, told me that if he moved the tweeter back to the front I would not like the sound at all. Why would you want your tweeter more than a foot in front of the midrange driver??!!....this is crazy. Its no wonder the highs arrive 10 years before the mids. There are several horn speakers out there that time align the drivers. And of course, tons of other speakers that time align as well. I have made several speakers over the years and even an eighth of an inch movement between the drivers is quite audible. Right now I am using a B&G Neo 10 and Neo 3 planar combo and two 6 inch woofs below. The mids and tweets are mounted on the same plane/baffle and the woofs are in their own box underneath and the mid/tweet open baffle panel is moved back by ear to make it sound great......and great it sounds. You can build a far better speaker than a K-horn for relatively very little money......planars, like mine, horn speakers, dynamic drivers, etc. Tons of really great drivers out there.

BIGHORN's picture

Acquired the 60th Anniversary KHorns some years ago and had to really work on them. Moving fast forward: time alignment is solved by mounting the tweeter on top, aligned with the midrange horn. With Live Dirac 2.0 in a MiniDSP DR22 other issues are solved, like the 9mSec bass lagging behind. With a FirstWatt F3 amp it really sings. Better than 300B tubes.
The involvement in the music is great, true 3D and no listening fatigue at all. As mentioned not a thundering bass but instruments do sound natural with great attack and presence. Who wants a dinosaurus in the room? Good recordings really shine.
I'm spoiled now because vented ports don't appeal anymore. I like horns.

mrquant's picture

I visited a vinyl bar, In Sheep's Clothing, in the arts district near downtown LA yesterday. This is a concept that I understand is popular in Tokyo. Basically it is like going to a small jazz club but the performer is a stereo rather than a jazz combo. People are encouraged to keep their voices down and enjoy the music. The system was 70s K-horns with Crites mods, audio note amps, and Garrard 301 turntables. You know, basically my garage system ;). They were playing some sort of experimental jazz I am not familiar with. The sound was great.

But to my point. The speaker wall had been constructed in a W shape with the middle peak flattened off. So the speakers were in the corners of the W but still pointed straight forward. It would be easy to do such a thing with 2x4s and some sheet rock. You wouldn't need to tape and plaster to do the experiment. I think I could bang it out in a day with help from a friend. If you liked the sound you could redo it nicer. Probably get a nice audio component or even TV space in the middle with some deep record shelves on the sides.

paulraffaele's picture

Hi there Klipsch commenters!

This seemed like an efficient way to meet some Klipsch fans in their natural habitat.

Here to tell you that on Tuesday March 17, we're launching a published edition of Paul W. Klipsch's cult audio newsletters, the 'Dope From Hope' via Kickstarter. Dope From Hope is a collection of audio papers authored by Paul W. Klipsch dating back to 1960.

We are running this project independently, but with the endorsement of both Klipsch Group International and the Klipsch Museum of Audio History.

The compendium of papers in their original form includes never-before-seen issues, hand-written drafts, and supporting images and diagrams. It'll also include a foreword by renowned audiophile Colleen 'Cosmo' Murphy (Classic Album Sundays) as well as Jim Hunter (Klipsch Museum of Audio History).

The final result will be a handsome cloth-wrapped, hardcover book with 400 full-color pages and smyth-sewn binding. Size will be approximately 10x12", perfect for the coffee table or record shelf.

Would love to hear from you! Below are some ways you can connect:

>> If you'd like to know more or want to request a press kit, drop us a line at info@dopefromhope.com.

>> Follow along on Instagram as we unearth amazing still and moving images from the Klipsch vaults at http://instagram.com/dopefromhope

>> Get on the mailing list so you're up on key moments during the campaign at http://dopefromhope.com

Aeriya's picture

I purchased my KC-BR's (Klipschorn Birch Raw) in 1977 for $1,000 each and still have and enjoy them. I spent about 1 year between 1990-1991 looking for a house that would accommodate them, no small feat in So. Cal. an odd place where a 10x10 room is called a bedroom. I removed a load bearing wall between two rooms and converted an 8 foot high truss ceiling to rafter. Room was 29' x 16.5' with 14' peak - listening position ~19 feet from those directional horns! Needless to say this construction cost significantly more than the speakers. Paul Klipsch recommended the 1.0 to 0.618 ratio of distance between speakers to distance from front wall to back wall and its important. Dude, you cannot sit 5 or 6 feet away from these speakers or they sound worse than awful. I am surprised Klipsch allowed you test them in that room with the speakers only 8' apart with listening distance even less.

I sold the Klipschorn house in 2019 and now only have tiny rooms and/or no suitable corners, so they are not hooked up. Why am I telling you this? You CANNOT listen to these speakers in a tiny room with any amplifier/DSP/etc. Did you ever see a photo of Paul with these things in a tiny room? No, they were shown with wide spacing and often with a single Belle Klipsch in between. The man would surely respond to this tiny room review as pure "Bullshit" ;-) Please consider re-doing this review in a room appropriate for this speaker.

Based on over 40 years experience with the same set of K-Horns in many environments, here are a few other suggestions for maximum enjoyment of the Klipschorns (only after you have a correctly sized room and listening position):

- Get the most massive, powerful quality subwoofer you can afford to fill your large room with silky 15Hz - 80Hz bliss. The bass that comes out of the horn is second to none but an exponential horn can only cover about 3 octaves which limits greatly the LF extension. Crossover at about 80Hz. Keep in mind that frequencies lower than the cutoff will reach the mouth of the horn and bounce back to the source, the sub will make sure this does not happen. I do not consider any version of the K-Horns a full range speaker. My sub is a 1999 Velodyne HGS-18 which has servo feedback to keep the distortion as low as possible to match with the horns.

- Get a single middle speaker to complete the sound stage. It doesn't have to be a Belle Klipsch either, although that would be nice.

- Buy a copy of the previously mentioned compilation of Paul's "Dope from Hope". I lost my originals so can't wait to get it. I think your enjoyment of the horns will be magnified when accompanied by these priceless writings and you may make changes that will improve the sound. I have no connection with the book.

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