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amirm

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It seems intuitive that we would all have different tastes in sound reproduction. After all, there are thousands of different brands and models of speakers each with a different sound. Surely that is due to different people liking different sounds. Another fact that bolsters this intuition is that there is no reference for audio. So in that sense, there is no metric of accuracy either meaning it is a free for all, allowing anyone to pick any sound as being what they prefer.

Well, everything I just said is wrong! Turns out we are remarkably alike in what we prefer subjectively. We seem to have an internal compass that points to good sound and that when we only use that compass, we are able to determine what is proper and what is not. Dr. Toole in his book, Sound Reproduction, Loudspeakers and Rooms puts this most eloquently:

"Descriptors like pleasantness and preference must therefore be considered
as ranking in importance with accuracy and fidelity. This may seem like a dangerous
path to take, risking the corruption of all that is revered in the purity of
an original live performance. Fortunately, it turns out that when given the
opportunity to judge without bias, human listeners are excellent detectors of
artifacts and distortions; they are remarkably trustworthy guardians of what is
good. Having only a vague concept of what might be correct, listeners recognize
what is wrong. An absence of problems becomes a measure of excellence. By
the end of this book, we will see that technical excellence turns out to be a high
correlate of both perceived accuracy and emotional gratification, and most of us
can recognize it when we hear it."

I will provide further proof of this but think of what our reaction would be to a cheap, boomy sub added to a system. I think we would all hear the same artifacts. The same overboosted bass.

As some of you know, Harman has built on work done by Dr. Toole and others while at Canadian National Research council (NRC) to attempt to better understand our subjective preferences in loudspeakers. This is done by performing double blind listening tests to see what makes a person like one speaker more than others. The latest incarnation of this is a speaker shuffler that is able to switch speakers in and out in about 4 seconds. Here is the fixture in their multi-channel listening room:

Harman Shuffler Testing Room.PNG


The platform under the speaker moves allowing the speakers to be swapped. Put a curtain in front of it and a computer controlled switching apparatus and you have a double blind test where the listener has to judge which speaker sounds better without any other influence.

Here is another room they have with the same capability that I attended:

IMG_1821-small.jpg


The story goes that Dr. Sean Olive who is in charge of this testing decided to measure the correlation between a specific set of measurements in the anechoic chamber and subjective preference in these double blind tests. His work is documented in a two part AES paper: http://www.aes.org/e-lib/browse.cfm?elib=12847

A Multiple Regression Model for Predicting Loudspeaker Preference Using Objective Measurements

The results were remarkable. Not only did he find a correlation but the match was nearly perfect in the same class as the speaker:

upload_2016-4-6_20-41-33.png


Note that this was not some specially selected speakers. On the contrary, it was a wide variety as Dr. Olive writes in the paper:

"The selection of 70 loudspeakers was based on the
the competitive samples purchased for performance
benchmarking tests performed for each new JBL,
Infinity and Revel model.

The price range of samples varied from $100 to
$25,000 per pair and includes models from 22
different brands from 7 different countries: United
States, Canada, Great Britain, France, Germany,
Denmark and Japan. The loudspeakers included
designs that incorporated horns and more traditional
designs configured as 1-way to 4-ways. Some used
waveguides, while others did not. The sample also
included four professional 2-way active models
referred to as “near-field” monitors. The vast
majority of the speakers were forward-facing driver
designs, with one electrostatic dipole sample."

The scale of testing was quite wide:

"The preference ratings for the 70 loudspeakers were
based on a total of 19 listening tests conducted over
the course of 15 months. All of the tests were
performed under identical double-blind listening
conditions, as described in Part One (see section 3).
Controlled variables common to all 19 tests include
listening room, program material, loudspeaker and
listener location, playback level, experimental
procedure and loudness normalization between
speakers.

The preference ratings in one of the tests are based on
the mean preferences of 268 listeners (12 trained and
256 untrained) reported in [24]. All other tests were
done using trained listeners"

I won't bore with pages and pages of statistics and analysis in the paper and go right to the punchline:

"A new model has been developed that accurately
predicts preference ratings of loudspeakers based on
their anechoic measured frequency response. Our
model produced near-perfect correlation (r = 0.995)
with measured preferences based on a sample of 13
loudspeakers reported in Part One. Our generalized
model produced a correlation of 0.86 using a
sample of 70 loudspeakers evaluated in 19 listening
tests. Higher correlations may be possible as we
improve the accuracy and resolution of our subjective
measurements,which is a current limiting factor."
Let me repeat. A set of objective measurements with no notion of what humans like or don't like, is able to highly predict what we like in the sound of speakers!

Still not convinced? Well, let's move to a different paper: http://www.aes.org/e-lib/browse.cfm?elib=12581
Differences in Performance and Preference of Trained versus Untrained Listeners In Loudspeaker Tests: A Case Study

As the title indicates, Dr. Olive wanted to see if their trained speaker listeners were biased to like their own speakers and hence, their preference did not match the general population. Instead of quoting the paper, allow me to post a graph from a powerpoint by Dr. Olive on this research:

Harman Trained vs Untrained.png


The horizontal axis is the name of the different groups that participated in the test. As you can see, one group was HiFi reviewers and the other of course the HARman trained listeners. The vertical scale is the preference. Each horizontal line graph represents a different speaker being blind tested by each group.

We see that the groups differ on what scores they give from each other. HARman trained listeners were highly critical, giving much lower scores with the green speaker for example getting nearly zero on preference. Reviewer group gave a score of 3 to the same speaker.

The important bit is the relative ranking of the four speakers tested. Harman trained listeners like every other group gave the green speaker the worst scores. At the other extreme the speaker in read garnered almost the same highest score from every group of listener which participated in the test.

On a personal level, I have take the same test and my votes were exactly the same as the larger population. I took the test twice, once with a group of dealers, and once with Harman employees and top acoustic experts. One Harman employee voted differently than the rest of us. I voted the same in both tests. And majority of dealers voted the same as me and the population.

So no, we do not have different preferences as a rule. You may be the exception but the odds are well against you being so.
 

Mivera

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The problem is they are all "Harman trained listeners" They are trained to be androids with all of the exact same listening preferences. And for those who aren't, they can't tell the difference anyways.
 
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amirm

amirm

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The problem is they are all "Harman trained listeners" They are trained to be androids with all of the exact same listening preferences.
No, that is not how they are trained. I will do a digest on their training in another article.

And for those who aren't, they can't tell the difference anyways.
Thanks a bunch seeing how I wrote that I have taken the test twice and agreed with the research outcome! :(
 

Dynamix

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The problem is they are all "Harman trained listeners" They are trained to be androids with all of the exact same listening preferences. And for those who aren't, they can't tell the difference anyways.

But why would Harman spend so much money on training listeners to prefer their own speakers? If that's what you're saying.

Because that's the usual argument, and it makes no sense. Wasting money on something that's not even going to be used for marketing. Why?
 

Mivera

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No, that is not how they are trained. I will do a digest on their training in another article.


Thanks a bunch seeing how I wrote that I have taken the test twice and agreed with the research outcome! :(

But I thought you were a trained listener? And just because everyone may have liked the same profile the best, it doesn't mean that they will if hooked up to different electronics in a different room.
 

Mivera

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But why would Harman spend so much money on training listeners to prefer their own speakers? If that's what you're saying.

Because that's the usual argument, and it makes no sense. Wasting money on something that's not even going to be used for marketing. Why?

Well they have their own "trained listeners" I'm sure they don't come from a background of paper cone full range drivers and Kondo tube amps.
 

Dynamix

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Well they have their own "trained listeners" I'm sure they don't come from a background of paper cone full range drivers and Kondo tube amps.

Hopefully not, no. :D
 

Mivera

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It actually looks like the trained listeners didn't really like any of the speakers that much. Maybe they went and bought a set of Magico's or something after the session :)
 

Dynamix

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Dynamix is right Amir. For an experiment train listeners to like Magico speakers, and share your results with us. :)

That's really not what I'm saying. What I'm saying is that (hopefully) Harman did not train their listeners to prefer Harman speakers. What would be the point of that, they'd learn absolutely nothing if that was the case.

(Full disclosure; I own a pair of JBL 4319 by Harman speakers, but it's not like I'm married to them or something. :p )
 

Dynamix

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It actually looks like the trained listeners didn't really like any of the speakers that much. Maybe they went and bought a set of Magico's or something after the session :)

Or some Zu's... :eek:
 

Mivera

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That's really not what I'm saying. What I'm saying is that (hopefully) Harman did not train their listeners to prefer Harman speakers. What would be the point of that, they'd learn absolutely nothing if that was the case.

(Full disclosure; I own a pair of JBL 4319 by Harman speakers, but it's not like I'm married to them or something. :p )

Do you not think that people who work there likely listen to harman speakers more often than any other brand?
 

Dynamix

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Do you not think that people who work there likely listen to harman speakers more often than any other brand?

They probably do. But where the people who work there a substantial part of the listening panel in the tests we are talking about?
 

Mivera

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They probably do. But where the people who work there a substantial part of the listening panel in the tests we are talking about?

They were in the "Harman trained listener area" And the others, well it's pretty easy to tune something so the majority will prefer it. It's like giving a kid some sugar, vs a lemon. Chances are they will respond in a more positive fashion to the sugar.
 

RayDunzl

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That's really not what I'm saying. What I'm saying is that (hopefully) Harman did not train their listeners to prefer Harman speakers. What would be the point of that, they'd learn absolutely nothing if that was the case.

Yes, after I've re-read your post I realized what you meant, so I discarded my post.
 
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Mivera

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Dynamix

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Yes, after I've re-read your post I realized that what you meant was still close enough, so I didn't change a thing.
Because, HK doesn't sell KEF or B&W speakers, but Revel, JBL, Infinity, and others.

The most convincing and best auditory tests are repeated year after year with the arrival of more advanced, technologically developed loudspeakers.
Today the Bose 901 doesn't hold that candle anymore in that 70's discotheque with guys wearing high healed shows with sailor pants and smoking hallucinogen substances. :D ...And playing music from

Ah, hallucinogens... Those were the days... :D
 

Dynamix

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Anyways, am I still allowed to enjoy my JBL's? Or what? :p
 

RayDunzl

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"All tests were performed double blind using monophonic (single-loudspeaker) comparisons."

Who listens like that?
 

Thomas savage

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We are all fairly similar in more ways than anyone should like to think. The broad strokes of the above seems ok to me, of course how each speaker would sound in our homes is another story and this may well lead to change of the preference dynamic.

You all are the same, you buy the same stuff.. Live by the same rules, get stressed by the same things, eat the same types of food stuffs etc etc... I am different because I am special.

I am odd that proves the rule.. I am special, special needs special everything.

:eek:
 
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