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Stereophile review of Klipschorn


Arkytype

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Testing a Khorn outside on a driveway? ROFLMAO

 

That's exactly what I would do if I wanted to manipulate the results in order to make that speaker look bad.

 

But I guess the dummy wanted to be "fair" because that's how he "measures" all of the speakers he tests. 

 

The Khorn is designed to be used in 1/8 space, i.e. in or very near a corner. The Stereophile tests were run in 1/2 space, i.e. in an open area with the Khorn sitting on a concrete driveway. No Bueno.

 

The way I understand the enclosed backs on the AK6 is that the speaker doesn't need to be pushed tightly into the corner of the room, and can be adjusted to aim toward the listening position.

 

The one thing I do agree with is that using a DSP and triamping the Khorn improves it's performance.

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1 hour ago, Don Richard said:

Testing a Khorn outside on a driveway? ROFLMAO

 

That's exactly what I would do if I wanted to manipulate the results in order to make that speaker look bad.

 

Or if you're of the "I don't need no stinkin' instructions -- I know what I'm doing" mindset. Maybe it's like people who salt their food before even tasting it -- force of habit.

 

I like to give people the benefit of the doubt. Hanlon's Razor https://en.wikipedia.org/wiki/Hanlon's_razor.

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The people at the magazine are taking hits in the comments section of the posted article at their own web site.  I wouldn't want to be in either of those guy's shoes right now. 

 

I'll let my first impressions stand.  It now looks as if the magazine now appears to have done a review that's either 1) a fiasco (i.e., incompetent), or 2) these two guys were "spring-loaded" in advance.  Atkinson really just did a huge reputational damage to himself, I believe.  Richard Heyser did an excellent review and produced tons of useful information--even considering that more than 33 years have elapsed.

 

Roy's upgrade of the passive crossover in the Khorn and the new tweeter driver and tractrix horn are likely extremely well done. If I had to believe one person, it's not difficult for me to take sides.  Roy also had access to an anechoic chamber that was constructed with the aim of being able to specifically test Khorns.  Which one would you believe?

 

Chris

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A DSP might help significantly.  When I tuned my Klipschorn system years ago, I started with Audyssey Flat, then hand tuned it by ear (using  tone controls and subwoofer gain) to a room curve with a bass rise of about 7 dB, a la Harmon, with the sub boosted about the target 7 dB.   The crossover to the sub was at 80 Hz, with the Khorns set for "small" (BION).  The response above 80 was about -2, +3 or  +/- 2.5 dB up to 16K, with 1/3 octave smoothing like Stereophile used to use with their room graphs.  This was based on using 8 calibrated microphone positions, which Audyssey then processed with a "fuzzy logic" procedure, rather than a simple set of averages.

 

It sounds great, by the way, with punchy dynamics and gravitas.

 

I would have liked to have seen from Stereophile:

  • Their usual room curve, averaged over 30 degrees, with the Khorns pushed into the corners, even if the toe in was adjusted a bit.
  • Distortion measurements.  Heyser and Keele were able to measure Harmonic and the all important IM distortion.  Klipsch routinely measured modulation distortion and found the Khorn to have only 1/3 as much total modulation distortion as their Cornwall, and at a higher SPL from the Khorn.
  • Some kind of acknowledgement of just how much dynamic range the Khorn has.  In my 4,257 cu ft listening room, a typical speaker with a sensitivity of 90 dB/2.83v/1m needs 1,024 watts to produce 114 dB, as measured 13 feet away, while a single Klipschorn needs only about 85.3 watts to produce the same SPL, at the same 13 feet away, in the same 4,257 cu ft room. 
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I suspect that PWK is livid. Everything bad he envisioned happening in having others review and measure his speakers seems to have transpired with this review. He felt that all speakers were corner speakers. Yet his very own legendary corner horn speaker was both reviewed and measured without proper corner placement. IMO Klipsch should be embarrassed for allowing this sorry excuse of a review to have transpired. 

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16 hours ago, garyrc said:

A DSP might help significantly. 

I believe that it does.  If you remember Greg Oshiro's thread from 2011, his impressions after tri-amping and dialing everything in (Greg works in the industry and was the inspiration for me to go ahead and start using REW and a more capable DSP crossover than the EV Dx38 that I was using):

 

Quote

Other impressions:

  1. Walking around the room, I can plainly hear the polar pattern of the tweeters. In the old passively crossed-over days, this was not so obvious.
  2. The passive crossover had a very"splashy" high-hat sound. It now sounds much more like the real thing.
  3. Reverb tail decay can now be heard in much greater detail. I use Steely Dan's "Babylon Sisters" track for this evaluation.
  4. Drum attack, especially toms, sound better.
  5. The "air" around saxophones is clearer.
  6. The difference between recordings with/without low-frequency extension is much clearer.
  7. It is easier to listen to individual instruments in a mix.
  8. Pianos sound much more realistic.
  9. I'm listening to Lyle Lovett's "Live in Texas" right now. I can hear him inhaling between phrases.

Overall, I'd say this doesn't suck. ;)

 

I would think that a turn-key Khorn DSP crossover tri-amp kit would include something like a Xilica XP4080 or XP8080 (or miniDSP 4x10 HD if you want to go the least expensive route), six channels of amplification--such as three stereo amplifiers--and associated cables.  The DSP settings can be found in Greg's Khorn tri-amping FAQ on page 2, linked above. 

 

Since the Khorn was PWK's baby (and he isn't around to give his blessing to doing a DSP crossover kit), I think that there's resistance to the idea of Klipsch providing a DSP crossover tri-amping kit, but I believe that it would be a fairly big seller if it were offered by Klipsch. 

 

As it stands, anyone that wants to DIY can tap into the existing support sound here on the forum.  It costs nothing for the dialing in process--all you have to do is get REW up and running and take some measurements, then email the measurement files to Chris A ("yours truly", as well as any others having DSP crossover experience), whereby you get configuration files emailed back to you for immediate import into XConsole (Xilica) or the equivalent miniDSP application for the 4x10 HD. 

 

How to integrate a DSP processor into your system:

 

 

The success and satisfaction rates have been very near 100%. "Bang-for-buck" is higher than any other upgrade that can be accomplished with Khorns and it facilitates the swapping out of midrange and tweeter horns/drivers without the usual resulting issues of crossover problems--the DSP crossover is waiting for you to make those changes--without added cost or significant effort. 

 

Chris

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 The manufacturers response to this review read like  A few paragraphs  copy/pasted from the website and brochure.

 

Instead, why didn’t Roy take Atkinson and Dudley to task for these review irregularities everybody is talking about? Seems like a missed opportunity to me.   The same thing happened with the forte review 

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40 minutes ago, Khornukopia said:

 

Getting into a debate on the internet can be very risky business these days. Sometimes it is better to just not give incorrect information any more exposure. 

 

 I don’t follow. I am referring to the Manufactures Response section in the back of the stereophile issue in which this review appeared.   This section of the magazine  is there to provide manufacturers a chance to respond to issues raised by a review. And there seems to be much here that Klipsch (i.e, Roy) could have responded to.   Of course Klipsch would not want to come across as being defensive, but there’s nothing wrong with politely crying foul over bad measurement techniques 

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Where we are:

Our power amplifiers (solid state & valve), preamplifiers (passive or active), CD players, DACs, turntables, integrated amplifiers & AV receivers all have one thing in common: Their “sound” is not affected by a room’s “acoustics” which include the dimensions, shape, dimensional ratios, reverberation time, standing waves, etc.

That leaves the loudspeaker which, for the most part, is at the mercy of the above “acoustics” for its “sound” and whose measurements we often question.   

 

Where we’ll never be:

In a perfect world, all reviewers in the audio magazine bidness would have identical listening rooms with the size (ratios, shapes) and acoustic treatment taken from the experience of notables such as Floyd Toole, Peter D’Antonio and the like. Then, maybe at least the objective measurements would be in closer agreement with the manufacturer’s specs. The subjective assessments would, however, be left to the whims, prejudices, and “golden ear wax” of the reviewers.

 

Where we could be:

If my memory serves me correctly, the factory listening room in Hope has four square corners but splayed side and end walls. I think it was constructed about the same time as the anechoic chamber.

 

Shameless Aside:

When the chamber was under construction (late 70s?), I visited the plant and found PWK spinning the revolving corner at maybe 40-60 RPM! I can still remember the whoosh of air as each partition went past. He quipped that he was testing the door’s bearings which were from a pair of truck axles. JRH probably was there as well as he drove a lot of the door’s unique, patented construction.

 https://patents.google.com/patent/US4387786?oq=klipsch

 

WWCB (Cont’d)

Anyhoo, I propose that Klipsch get a qualified acoustic consultant and outfit that listening room (Indy's as well) with the proper wall/ceiling/floor treatment that any manufacturer in the loudspeaker bidness should have to highlight their products. The present wall “treatment” at Hope is just sad. What we are striving for is an “ideal” acoustical space using proven solutions; not a few pieces of “acoustical” foam and wall-to-wall carpeting.

https://community.klipsch.com/index.php?/topic/177136-klipschorn-new-build-introduced-to-pilgrimage-attendees/

 

Next, starting with each Heritage loudspeaker, measure every electrical and acoustical parameter known using state-of-the-art, calibrated gear, not a laboratory microphone adapted for entertainment use and the decades-old MLSSA testing software John Atkinson uses.

 

Audio Precision not only manufacturers top-of-the-line measurement gear but also has some powerful, easy-to-use loudspeaker measurement suites. One can make more than a dozen accurate, repeatable acoustic measurements in a few seconds with a single mouse button click.

https://www.ap.com/electro-acoustic-test/

 

Just think, you could start with a pair of Cornwall IIIs in the corners with the tweeter axis pointed at the microphone (at the listening position); take a slew of measurement; and then gradually move the CWIII toward the center all the while taking comparison measurements.

Of course, these comprehensive measurements would trickle down the product line as warranted. As a “reference” each loudspeaker would be tested in the trihedral corner of the anechoic chamber to compare FR curves and those pesky sensitivity specs with those taken in the listening room.

 

Finally: The end result of these measurements would be to, a) have a baseline for each loudspeaker model which could (should?) be used in product advertising, and b) could (should!!) be used to refute/dispute an audio magazine’s poor measurement results.

 

In the case of the AK6 review, if Roy was privy to the poor measurement results prior to publication, he should have (at the least) moved heaven and earth to get those measurements re-done indoors or used the Manufacturer’s Comment section to strongly contest the AK6’s poor measurements.

 

 

 

Lee

  

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1 hour ago, ODS123 said:

The manufacturers response to this review read like  A few paragraphs  copy/pasted from the website and brochure.

 

I strongly disagree with this quoted statement.

 

Roy's response stating four of Paul W Klipsch sound principles in order of importance was very important because they are the basis for the Klipschorn design since the beginning and have never changed and it should lead those not familiar with them and the science/physic behind them to begin educating themselves as soon as possible if accurate sound reproduction is important to them.

 

I believe Roy's response was reaching past Stereophile and it's review/reviewer in an attempt to get people to think and wonder how a loudspeaker can have a design that has lasted over 70 years and is still very relevant as a sound reproducer to this day and with that understanding hopefully people will make all efforts possible to experience the Klipschorn.

 

All anyone has to do is compare the Klipschorn review by Richard C Heyser in Audio versus this Stereophile review to understand how poorly and inadequate in implementation the Stereophile Review was performed in all respects.

 

miketn

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9 hours ago, ODS123 said:

I am referring to the Manufactures Response section in the back of the stereophile issue in which this review appeared.   This section of the magazine  is there to provide manufacturers a chance to respond to issues raised by a review.

 

Thanks for pointing this out. 

 

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High Fidelity did a "review" of the LaScala in the 70s, I think. The published curve was really bad. PWK was able to closely duplicate the curve by putting a LaScala on a stool away from walls and putting the microphone behind the system. He raised so much hades that HiFi withdrew the review.

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If someone out there has a pair of AK6 Klipschorns that are pushed into the corners (even if toed in at something slightly different than a 45 angle), and sound good, I'd be very interested in seeing some frequency sweeps done on REW (free) with a calibrated mic, with both 1/3 and 1/6 smoothing, with the mic placed at the Main Listening Position. 

 

I don't have AK6s, and I'm no longer set up for doing sweeps (my mic needs a mic preamp and aux power, and the little box that provided both has conked).  Based on my old results with an AK4, without EQ, I'd expect about +/- 5.5 dB from about 38Hz to 15KHz, and bass extension, highly attenuated, of course, to 25 Hz with REW (and to 16 Hz with the Diapason disk -- I'm suspicious, but I can hear/feel it clearly).  With EQ (Audyssey Flat), I'd expect about +/- 2.5 dB 32 Hz to 15KHz.  Everything stops above about 16.5K Hz, but that's with the old tweeter (K77F).

 

All this nonwithstanding, smooth frequency response doesn't loom large among my favorite speaker attributes.  Whatever combination of attributes makes a speaker sound good to me ... makes a speaker sound good to me.  Whatever makes it sound plausibly like the orchestras I've played in, or the orchestra concerts I've heard ... is whatever makes a speaker sound real to me.  Etc.  I strongly suspect that it has little to do with frequency response, and a lot to do with plausible dynamics, "speed," low distortion, and the like.   Some of the worst speakers I've ever heard were the very flat "acoustic suspension" (not identical with "infinite baffle," regardless of what some catalogs now say) type, a big deal in about 1959 (Consumers Reports), and still hanging on today.  As an orchestrally sophisticated youngster visiting his first Hi Fi fair, it was clear to me that the lauded AR 1 with an electrostatic tweeter added on did not sound natural, but the Klipschorn, the EV Patrician, the JBL Ranger Paragon, and the like, did.  The AR3A, a few years later, was no nearer reality.  Sure, the AR3A had "fuller" bass than the Paragon, but the Paragon made it sound like the instruments were playing in front of me, both individually, and the whole Gestalt. The other horn loaded speakers were also not all that flat, but reach out and touch it real and very, very "musical."  As far as I can tell, there has been astoundingly little change; the best speakers I continue to hear are "fast," highly dynamic, relatively undistorted with a surprising clarity, i.e., horns.  Too bad they are so hard to find.

 

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On 8/10/2019 at 5:09 PM, Arkytype said:

The September 2019 edition of Stereophile has a long-awaited review of the AK6 Klipschorn.

 

The only word that comes to my mind after reading both the Measurements section and the review by Art Dudley is----disappointment.

 

First the measurements: Once again, a Klipsch loudspeaker does not meet  its sensitivity specification. That's odd for a Klipschorn as I would assume its sensitivity was measured in the trihedral corner of the Hope anechoic chamber (see grainy image). You'd think there would be less of the "room gain fudge-factor" Klipsch uses than the 3.9 dB sensitivity shortfall John Atkinson measured. 

 

For logistical reasons, the AK6 was measured out of doors sitting on a driveway. The AK6 frequency response specification is 33 Hz--20kHz + or - 4 dB. For a premium-priced loudspeaker, that spec should be + or - 3 dB or better.

 

Atkinson measured the AK6 frequency response using nearfield (bass horn) and farfield (squawker/tweeter) measurement techniques. The AK6 frequency response measured: 33 Hz -20kHz +8 dB minus 15 dB (my interpretation of the FR curves). The +8 dB peak at 10kHz is as disappointing as the overall tweeter level which appears to be 3 dB too hot relative to the midrange. I won't comment on the bass horn measurements only to say that even though the back is enclosed, corner placement is, IMHO,  the only location to measure the bass response of a Klipschorn. 

 

Second, the listening test: It wasn't clear from  Dudley's review how the Klipschorns were located in his 17' x 12' x 8' listening room. Were they on the long wall or short wall?

 

Dudley writes, I began with the backs of the Klipschorn AK6s a short distance from the front wall--their front surfaces, measured at the centers of the cabinets, were a little more than 3' from that wall, and a little more than 8' apart from each other--and with the the speakers slightly toed-in toward the center listening seat.  

 

Really? Where's my horsewhip? Who in their right mind would listen to Klipschorns eight feet apart and three feet away from a wall? 

 

In 2006 Klipsch turned down Dudley's request to review the 60th anniversary Klipschorn because his (Dudley's) listening room at the time couldn't accommodate corner placement. Did the current Klipsch marketing department considered asking for dimensions and images of Dudley's current listening room? 

 

His current listening room would IMHO be marginal even locating the AK6s on the 17' wall.  My listening room was designed around my Klipschorns/Belle and is 24' wide, with 11' high side walls and a 23' vaulted ceiling. The sound quality and imaging is magnificent and is a system not tolerant of poorly recorded pablum. 

 

Unfortunately, I cannot scan the AK6 review and post it----my trusty Epson scanner is refusing to power up. Stereophile will post it soon enough on their web site. Gosh, you'd think Klipsch would have posted the past two Stereophile Klipsch loudspeaker reviews on the web site by now.

 

 

 

Lee

 

 

PWK chamber.jpg

Lmao 

 

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20 hours ago, garyrc said:

...Based on my old results with an AK4, without EQ, I'd expect about ±5.5 dB from about 38Hz to 15KHz, and bass extension, highly attenuated, of course, to 25 Hz with REW (and to 16 Hz with the Diapason disk -- I'm suspicious, but I can hear/feel it clearly).  With EQ (Audyssey Flat), I'd expect about ±2.5 dB 32 Hz to 15KHz.  Everything stops above about 16.5K Hz, but that's with the old tweeter (K77F).

 

All this notwithstanding, smooth frequency response doesn't loom large among my favorite speaker attributes.  Whatever combination of attributes makes a speaker sound good to me ... makes a speaker sound good to me.  Whatever makes it sound plausibly like the orchestras I've played in, or the orchestra concerts I've heard ... is whatever makes a speaker sound real to me.  Etc...

 

I strongly suspect that it has little to do with frequency response, and a lot to do with plausible dynamics, "speed," low distortion, and the like...

One of the great missing links to the loudspeaker engineering repertoire (IMO) is a ranking of loudspeaker performance attributes by measurement type--not based on someone's opinion of what is important, but rather by subjective preference by listener groups on particular loudspeaker types (by listening group preferences), and then an analysis of how the most preferred loudspeakers actually performed, i.e., an approach that is reversed from the engineering literature on loudspeaker measurements. 

 

The following loudspeaker capabilities types are presented from a notable writer on this subject--Joseph D'Appolito (author of Testing Loudspeakers (1998, Audio Amateur Press) an excellent resource for learning about these measurements and what they mean), based on "30 years of designing loudspeakers".  What he didn't mention was that virtually all of these loudspeaker types are direct radiating types, using cone and dome-type drivers in a "monkey coffin" type of small enclosure, with no precedence given within the group:

  • Frequency response
  • Impulse response
  • Cumulative spectral decay
  • Polar response
  • Step response
  • Impedance
  • Efficiency/Sensitivity
  • Distortion
  • Dynamics

 

Rearranging the above and expanding the list to include some missing measurements, the following list of revealed capabilities based on the Khorn's performance in each of the measured areas:

 

  1. Full-range directivity (particularly below 800 Hz)
  2. Modulation Distortion
  3. Compression Distortion
  4. Efficiency/Sensitivity
  5. Cumulative spectral decay (especially below 800 Hz)
  6. Room dimensions/loudspeaker placement
  7. Near-field room absorption around loudspeakers

 

The following list of loudspeaker capabilities are significantly depreciated with regard to those preferring the Khorn's sound reproduction:

 

  1. Frequency response flatness (particularly below 200 Hz)
  2. Impulse response
  3. Input Electrical Impedance

___________________________________________________________________________

Each of the above seven capabilities have associated measurements:

  1. Directivity -- measured via multiple upsweeps with microphone at a set radial distance from centerline of loudspeaker, usually in 10-15 degree lateral and vertical increments, combined into a "polar spectrogram" view, i.e.,

K-402-MEH horizonal normalized sonogram.jpg

 

2. Modulation distortion -- measured via dual-tone test, looking at the relative amplitude of the sideband spikes around 450 Hz in this instance:

 

846336291_JubBassBinDualToneTest30-450Hz.thumb.jpg.6511f352fab59cc4a78244b4ab658bc5.jpg

 

3. Compression distortion -- measured via multiple on-axis upsweeps at increasing SPL (trace arithmetic 75 dB [blue trace] overlaid on 100 dB [red]):

 

1268786423_JuBelleCompressionResponse75-100dB1mOn-Axis.thumb.jpg.a9a9f49c8c75b386fc0d2c408e737483.jpg

 

4. Efficiency/Sensitivity -- measured by calibrated output to a given calibrated input power or voltage level (looks just like an on-axis SPL/frequency plot)

 

5. Cumulative Spectral Decay -- measured by waterfall plot:

 

1008217999_JuBelle100dB1mOn-AxisWaterfall.thumb.jpg.94966bac58dfbd0ba464bd4f0af49686.jpg

 

6. Room Acoustics/Loudspeaker Placement -- measured via Energy-Time Curve (ETC) plot (which also shows room acoustics performance):

 

961674619_RightJubileeETC9June2019.thumb.jpg.207b8764d972b9615ee1997807dea58c.jpg

 

7. Near-field room absorption around loudspeakers -- measured early decay time (EDT):

 

2116731638_JuBelle100dBEarlyDecayTime(EDT).thumb.jpg.5d5490a2480b435c1290638c7231062a.jpg

 

The point to showing these example plots is that the real measurements that make a difference to those people that prefer the sound of Khorns and other Heritage Klipsch loudspeakers--aren't found in Mr. Atkinson's measurements for his magazine.  In effect, he's saying "one size fits all, and my measurements are important, but the ones that you want to see, well, good luck...I'm not going to post that data".  So the value of the magazine review is, in effect, zero--because the people setting up the loudspeakers in their selected room (which apparently was a poor room to use as an example for a good installation of Khorns) and the measurements that the technical editor wants to post...simply do not represent what you need to see and hear if you were a prospective Khorn buyer.  The entire article is a waste of everyone's time.

 

Chris

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Let's slow down a bit guys. John Atkinson knows what he is doing. However, why he chose to do it this way will remain a mystery. 

 

At the end of the day, does it matter? If Art Dudley was tepid in his enthusiasm, it does not matter. Most of us have heard various speakers and we have also heard the Klipschorn. For me, and others, the Klipschorn sounds fantastic. At $15000, it is an absolute steal. So I guess it really doesn't matter what Art Dudley thinks. My enjoyment has not been endangered. 

 

Regarding the measurement technique ... well sorry everyone, even if the Klipschorn (or the Jubilee) was measured "correctly", it will not have a ruler flat response. There will be peaks and dips. Guess what,  my Jubilees have peaks and dips (just like what Roy measures), and I love the Jubilees. I have listened to very few speakers that do a better job. So I really don't care what John Atkinson measures (even if it was in a corner loaded, eighth-space  environment etc or not).

 

Stereophile is a magazine. That is all it is. Don't let it ruin your listening pleasure. 

 

Good Luck,

-Tom

 

 

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Chris A wrote, One of the great missing links to the loudspeaker engineering repertoire (IMO) is a ranking of loudspeaker performance attributes by measurement type--not based on someone's opinion of what is important, but rather by subjective preference by listener groups on particular loudspeaker types (by listening group preferences), and then an analysis of how the most preferred loudspeakers actually performed, i.e., an approach that is reversed from the engineering literature on loudspeaker measurements. 

 

The person who is perhaps the most responsible for quantifying listener preferences in a loudspeaker is Floyd Toole. He has conducted hundreds (if not thousands) of blind listening tests at Canada's National Research Council with participants ranging from professional musicians to volunteers. I won't spoil the resulting findings. His latest book is well worth the investment. 

 

Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms (Audio Engineering Society Presents) 3rd Edition

 

He also is on several informative YouTube videos.

 

Lee

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