Klipschorns are one of the most controversial of speakers. In my "90% . . ." thread I mentioned that horn loading is one of the paths some designers take to minimize the interaction between speakers and room. Of horn speakers, the K-horn is probably the most famous and has the distinction of being in continuous production for well over 60 years, longer by far than any other speaker in history. Here are my personal perceptions of the sound of Klipschorns. As I said, K-horns are controversial and opinions not only vary widely, but are usually extremely polarized: listeners seem to either love 'em or hate 'em.
Dynamically, the K-horns take no prisoners. A part of this is undoubtedly due to very high sensitivity of the design at 104 dB/watt/meter. They make even the 95 dB/watt Legacy Whispers I once owned sound dynamically constrained. This is readily apparent on most any program material, but more so on classical "power music" and especially any rock or jazz with a good rhythm section. For some listeners--and on some days, with some material, I count myself as one--this carries everything else before it and the K-horns seem unbeatable.
After the initial excitement goes away, however--and that may not take longer than a few minutes of listening--and especially on reflection when not actually being aurally tempted by their charms, reality hits.
You must have two good solid corners behind the K-horns and they must be placed tightly right into those corners. Even with this, real bass, although very realistic sounding for all types of drums, only goes down to 35-40 Hz or so--deep enough for drums, but not deep enough to energize the room on organ fundamentals.
The tweeters beam and you must listen directly on axis to get true high frequency extension. When pushed into square corners, the tweeters thus fire at 45 degrees to the adjoining wall surfaces. While some owners have taken the top section off the woofer cabinet and/or enclosed the the woofer cabinet with additional plywood, allowing the mid/high horns to be rotated (the 60th Anniversary edition had a closed back as sold), barring such machinations this means that the speakers must subtend a 90-degree angle from the listening position. I like wide separation, as I've said. But many will find this amount of separation too extreme for most material in most rooms. So did Paul Klipsch, hence his recommendation for using a Cornwall or Bell Klipsch as a center mono speaker.
But while that fills in the middle, unless the wall between the corner horns is constructed in an arc (rare outside a converted circular barn), the center speaker will be too close and will require some sort of digital or analog delay in line with the signal, in addition to a volume control, to keep the sound from the center speaker from being severely phase-misaligned with the corner horns. The easiest way these days to time and volume align the center speaker is to use an AV receiver or pre-pro to handle this task.
A listening position where the speakers subtend a 90-degree angle also puts you fairly close to the speakers. This is the reason most people follow Klipsch's original recommendation and put the long wall between the speakers. You will then be 1/2 the length of the long wall from the plane of the speakers. If that wall is 20 feet long, you will be 10 feet away. That spot may be in a bass null or maxima for the room and there is no way to change that result by moving the speaker locations.
There must be no large objects or even surface irregularity on the wall surfaces between the horns or several feet along the side walls. Even wall acoustical treatment seems to kill the bass and severely limit the ability of the speakers to form images and stages. The speakers like live, uninterrupted wall surfaces, in other words.
Listened to on axis, there is good high-frequency extension, but there is brightness and smear in the upper midrange and treble. A substantial part of this is caused by early strong reflections from the wall right beside the speakers. While corner placement minimizes the percentage of wall surface which can act as mirror for reflections of mid and high frequencies, the drivers really aren't exactly in the corner but a couple of feet in front of the corner. Yes, you can pad the corners with Sonex or other absorbent material, but you need a lot of padding, thickness-wise, due to the strength of these reflections since the drivers are so near the walls and the more padding the more you interfere with bass, imaging, and staging.
The close-to-wall-and-corner placement also inhibits perception of depth of stage. In my experience, it is harder perceive stage depth when the sound emanates from close to the wall behind the speakers than when the speakers are set up well out into the room. K-horns are not unique in having this problem when placed near the wall behind them, but I think the corner placement exaggerates this problem by placing the wall reflection spots very close to the drivers. With other speakers, you have more placement choice. With K-horns, you have to live with the sonic products of close-to-corner placement.
The 104 dB sensitivity of a K-horn also reveals system noise and hum you might not realize was there with other speakers.
All that said, yes, I do like to hear K-horn systems in some rooms in small doses. Under the right conditions the sound can be unbelievably dynamic and exciting; truly the band is there in front of you.
Paul Klipsch used to say what the world needs is a good 5-watt amplifier to get the best from his horns. Many K-horn owners gravitate toward tube amps, particularly low-wattage SET types. In my opinion this is wishful thinking. Horns and SETs go together because horns are the only speakers efficient enough to produce decent volume and reasonably lifelike dynamics with amps having no more than 40 watts per channel, most with less than 10 watts.
Yes, with most speakers SET amps are usually "sweet" sounding, but that is basically because they both roll off the extreme highs and warm up the mid-bass. They are also "easy on the ears" since they constrict dynamics--in combination with their sweetness, this makes them sound polite or at least non-aggressive. There is never any truly deep bass from SETs, even if hooked up to a speaker which is capable of it with other amps.
What sets SETs apart is the way they sound in the midrange. Again there is "sweetening" going on, but this time it's because these amps have relatively high amounts of second harmonic distortion, as opposed to the 3d harmonic and other odd-order harmonics common to most transistor gear. Research has long showed that people actually like the sound of added second harmonic and that in fact there is almost no reasonable upper limit on the appreciation for such. And, if you push an SET amp toward its power limits, if it is designed properly it will just increase its amount of midrange 2d harmonic, and reduce bass and highs due to bandwidth limiting at higher power. Fletcher Munson effects reduce the audibility of the reduced bass and highs and you get more of that "magic" midrange due to the added distortion. Some find it addictively smooth and relaxed. I just yawn.
Lots of K-horn users swear by SETs. I think the reason is that the bass limitations in the lowest octave aren't apparent and that the sweetening of the highs and midrange mentioned above counteract to some extent the brightness smear and other irritation inevitably caused by corner placement and othe factors.
Those other factors probably include the choice of drivers and the characteristics of the midrange and treble horns. Some K-horn owners have very good ears and have worked hard to conquer or at least alleviate the brightness and irritation in the upper ranges through more radical measures than merely choosing sympathetically colored amps. Greg Roberts of Volti Audio may have the ultimate K-horns on offer. If you take advantage of all his mods, what is left is only the basic K-horn cabinet; all the drivers, wiring, and crossover components are replaced, and a new veneer can be added. Others have tri-amped the K-horns with DSP used to cross over and time align the drivers.
On the other hand, you must remember that the K-horns sell for "only" $8,000 the pair. Compare that to the pricing of the Avant Garde horn models, for example. I would much rather listen to K-horns than the $10,000+ Avant Garde Solo. The Solo is quite colored in the megaphone sense. The larger Avant Garde models ones have less of that but are incoherent (separate sound sources quite audible) unless you are back pretty far. The Solo has no real bass; the more expensive models in the line have non-horn bass which I don't think keeps up with the rest of the dynamics.
No, the Avant Gardes don't have to be in corners so you don't get the inevitable brightness/glare from wall reflections like with the K-horn, but I find their vowel-like megaphone colorations harder to listen around than the Klipschorn colorations, and the Klipsch are certainly vastly more coherent from close up, and have much better bass. I have never had an adrenaline rush from the Avant Gardes, whereas that is very common with K-horns and live music. Overall, I think the K-horn is a reasonable alternative to the larger Avant Garde models, at a small fraction of the price.
The Legacy Whispers I previously owned are advertised as having that dynamic "breath of life," and I agree, that compared to most speakers they do. But compared to the Klipschorns, they fall short in the department of fooling you that the music is live when you are only paying partial attention.
Also on the positive side, the K-horns, do the "live in the next room" thing much better than most other speakers. I have never heard a satisfactory (to me) explanation of what aspects of a reproducing system are important for that effect--it surely isn't frequency response or anything to do with spatial effects.
Bottom line, as to stock Klipshorns, I tend to agree with the sonic comments made by Richard Heyser in his review of them in Audio magazine many years ago. You can see this review by linking to each separate page of the review from here.
Dynamically, the K-horns take no prisoners. A part of this is undoubtedly due to very high sensitivity of the design at 104 dB/watt/meter. They make even the 95 dB/watt Legacy Whispers I once owned sound dynamically constrained. This is readily apparent on most any program material, but more so on classical "power music" and especially any rock or jazz with a good rhythm section. For some listeners--and on some days, with some material, I count myself as one--this carries everything else before it and the K-horns seem unbeatable.
After the initial excitement goes away, however--and that may not take longer than a few minutes of listening--and especially on reflection when not actually being aurally tempted by their charms, reality hits.
You must have two good solid corners behind the K-horns and they must be placed tightly right into those corners. Even with this, real bass, although very realistic sounding for all types of drums, only goes down to 35-40 Hz or so--deep enough for drums, but not deep enough to energize the room on organ fundamentals.
The tweeters beam and you must listen directly on axis to get true high frequency extension. When pushed into square corners, the tweeters thus fire at 45 degrees to the adjoining wall surfaces. While some owners have taken the top section off the woofer cabinet and/or enclosed the the woofer cabinet with additional plywood, allowing the mid/high horns to be rotated (the 60th Anniversary edition had a closed back as sold), barring such machinations this means that the speakers must subtend a 90-degree angle from the listening position. I like wide separation, as I've said. But many will find this amount of separation too extreme for most material in most rooms. So did Paul Klipsch, hence his recommendation for using a Cornwall or Bell Klipsch as a center mono speaker.
But while that fills in the middle, unless the wall between the corner horns is constructed in an arc (rare outside a converted circular barn), the center speaker will be too close and will require some sort of digital or analog delay in line with the signal, in addition to a volume control, to keep the sound from the center speaker from being severely phase-misaligned with the corner horns. The easiest way these days to time and volume align the center speaker is to use an AV receiver or pre-pro to handle this task.
A listening position where the speakers subtend a 90-degree angle also puts you fairly close to the speakers. This is the reason most people follow Klipsch's original recommendation and put the long wall between the speakers. You will then be 1/2 the length of the long wall from the plane of the speakers. If that wall is 20 feet long, you will be 10 feet away. That spot may be in a bass null or maxima for the room and there is no way to change that result by moving the speaker locations.
There must be no large objects or even surface irregularity on the wall surfaces between the horns or several feet along the side walls. Even wall acoustical treatment seems to kill the bass and severely limit the ability of the speakers to form images and stages. The speakers like live, uninterrupted wall surfaces, in other words.
Listened to on axis, there is good high-frequency extension, but there is brightness and smear in the upper midrange and treble. A substantial part of this is caused by early strong reflections from the wall right beside the speakers. While corner placement minimizes the percentage of wall surface which can act as mirror for reflections of mid and high frequencies, the drivers really aren't exactly in the corner but a couple of feet in front of the corner. Yes, you can pad the corners with Sonex or other absorbent material, but you need a lot of padding, thickness-wise, due to the strength of these reflections since the drivers are so near the walls and the more padding the more you interfere with bass, imaging, and staging.
The close-to-wall-and-corner placement also inhibits perception of depth of stage. In my experience, it is harder perceive stage depth when the sound emanates from close to the wall behind the speakers than when the speakers are set up well out into the room. K-horns are not unique in having this problem when placed near the wall behind them, but I think the corner placement exaggerates this problem by placing the wall reflection spots very close to the drivers. With other speakers, you have more placement choice. With K-horns, you have to live with the sonic products of close-to-corner placement.
The 104 dB sensitivity of a K-horn also reveals system noise and hum you might not realize was there with other speakers.
All that said, yes, I do like to hear K-horn systems in some rooms in small doses. Under the right conditions the sound can be unbelievably dynamic and exciting; truly the band is there in front of you.
Paul Klipsch used to say what the world needs is a good 5-watt amplifier to get the best from his horns. Many K-horn owners gravitate toward tube amps, particularly low-wattage SET types. In my opinion this is wishful thinking. Horns and SETs go together because horns are the only speakers efficient enough to produce decent volume and reasonably lifelike dynamics with amps having no more than 40 watts per channel, most with less than 10 watts.
Yes, with most speakers SET amps are usually "sweet" sounding, but that is basically because they both roll off the extreme highs and warm up the mid-bass. They are also "easy on the ears" since they constrict dynamics--in combination with their sweetness, this makes them sound polite or at least non-aggressive. There is never any truly deep bass from SETs, even if hooked up to a speaker which is capable of it with other amps.
What sets SETs apart is the way they sound in the midrange. Again there is "sweetening" going on, but this time it's because these amps have relatively high amounts of second harmonic distortion, as opposed to the 3d harmonic and other odd-order harmonics common to most transistor gear. Research has long showed that people actually like the sound of added second harmonic and that in fact there is almost no reasonable upper limit on the appreciation for such. And, if you push an SET amp toward its power limits, if it is designed properly it will just increase its amount of midrange 2d harmonic, and reduce bass and highs due to bandwidth limiting at higher power. Fletcher Munson effects reduce the audibility of the reduced bass and highs and you get more of that "magic" midrange due to the added distortion. Some find it addictively smooth and relaxed. I just yawn.
Lots of K-horn users swear by SETs. I think the reason is that the bass limitations in the lowest octave aren't apparent and that the sweetening of the highs and midrange mentioned above counteract to some extent the brightness smear and other irritation inevitably caused by corner placement and othe factors.
Those other factors probably include the choice of drivers and the characteristics of the midrange and treble horns. Some K-horn owners have very good ears and have worked hard to conquer or at least alleviate the brightness and irritation in the upper ranges through more radical measures than merely choosing sympathetically colored amps. Greg Roberts of Volti Audio may have the ultimate K-horns on offer. If you take advantage of all his mods, what is left is only the basic K-horn cabinet; all the drivers, wiring, and crossover components are replaced, and a new veneer can be added. Others have tri-amped the K-horns with DSP used to cross over and time align the drivers.
On the other hand, you must remember that the K-horns sell for "only" $8,000 the pair. Compare that to the pricing of the Avant Garde horn models, for example. I would much rather listen to K-horns than the $10,000+ Avant Garde Solo. The Solo is quite colored in the megaphone sense. The larger Avant Garde models ones have less of that but are incoherent (separate sound sources quite audible) unless you are back pretty far. The Solo has no real bass; the more expensive models in the line have non-horn bass which I don't think keeps up with the rest of the dynamics.
No, the Avant Gardes don't have to be in corners so you don't get the inevitable brightness/glare from wall reflections like with the K-horn, but I find their vowel-like megaphone colorations harder to listen around than the Klipschorn colorations, and the Klipsch are certainly vastly more coherent from close up, and have much better bass. I have never had an adrenaline rush from the Avant Gardes, whereas that is very common with K-horns and live music. Overall, I think the K-horn is a reasonable alternative to the larger Avant Garde models, at a small fraction of the price.
The Legacy Whispers I previously owned are advertised as having that dynamic "breath of life," and I agree, that compared to most speakers they do. But compared to the Klipschorns, they fall short in the department of fooling you that the music is live when you are only paying partial attention.
Also on the positive side, the K-horns, do the "live in the next room" thing much better than most other speakers. I have never heard a satisfactory (to me) explanation of what aspects of a reproducing system are important for that effect--it surely isn't frequency response or anything to do with spatial effects.
Bottom line, as to stock Klipshorns, I tend to agree with the sonic comments made by Richard Heyser in his review of them in Audio magazine many years ago. You can see this review by linking to each separate page of the review from here.