Can Objective Loudspeaker Measurements Predict Subjective Preferences?

Can measurements predict listening preferences in loudspeakers?

  • Yes. If the proper measurements are conducted

    Votes: 39 66.1%
  • No. What we hear is far too complex to fully quantify empirically.

    Votes: 12 20.3%
  • Who cares. Just get what sounds good to you and be done with it.

    Votes: 8 13.6%

  • Total voters
    59
highfigh

highfigh

Audioholic Overlord
Ratings
3,304 9 15
#23
Yes it is quite likely that poor loudspeakers in home studios are responsible for a lot of flawed sound. But bad loudspeakers have always been around, even now in some supposedly prestigious studios. On top of this, there is the guessing game of "room EQ", which is rampant in both consumer and pro rooms.

This problem also exists in the film sound business. We can all be grateful that humans are so adaptable - and forgiving - to allow the music itself to be enjoyed.
I have noticed my own tendency to stop listening critically when I can't leave a place where the sound may be incredibly bad unless it's so bad that there's no other option and I can't leave. If it's bad enough and actually uncomfortable or may damage my ears, I just put in my ear plugs and carry on.

The ability of the human mind to become acclimated to the sound of one speaker that may be considered 'terrible', even by lenient standards, is one of the obstacles dealers have to face when someone who has only listened to a few (bad) speakers hears what a better/great speaker can do. I think that may be one of the reasons students judged the speakers the way they did in your listening tests- they're not experienced in critical listening and on the other end of the spectrum were the retail salespeople, who do it on a regular basis. Sales reps performed as I would expect, on average. Some actually know great sound, but too many lack understanding of what they're selling and can't describe the sound of one speaker vs another very effectively.

Do you have a list of the music used for the listening tests? While I constantly look for new material to use for demonstrations, I also let people bring their own- I don't see any point in using music someone will never listen to and even though bad quality copies or mixes may not be preferable, it still needs to sound good to that person. I do like exposing people to music that's outside of their normal range, though. I have often used music that's not very well known and when I tell the person who it is, they ask, "Who?" because they have never heard of the artist/group.

We had a lot of teenaged kids coming into the store, asking for recommendations so they would be better prepared when they could afford to buy something and many were in the "If it's loud, it's great!" camp. We enjoyed educating them and several still have some/all of the equipment, 30+ years later.
 
highfigh

highfigh

Audioholic Overlord
Ratings
3,304 9 15
#24
Now that you have created a subjectively better sounding speaker, how do you sell it!
I would try to put them in places where people can hear them without a special trip, with info about the speakers, available to anyone who wants it, but not in a way that could be annoying. It wouldn't be blaring something different from the normal programming, so whatever is playing wouldn't be unexpected.

I would really like to get bar/restaurant owners to understand that the sound from their system isn't contributing to the enjoyment of the customers. I went to one the night Wisconsin won the NCAA basketball tourny- in the upper area, two speakers were disconnected and at least one didn't have a working woofer. These are basically PA speakers with a 12" woofer and a horn, so that was actually painful at the SPL they were using. The sound of people yelling and screaming, with the stupid comments from the announcers was almost unbearable. I stuffed in the ear plugs and it was still terrible. We went to the lower level after dinner and it didn't sound great, but it was tolerable. A couple of other places here have pine board walls and ceiling, in an attempt to seem like a lodge. Horrible acoustics- maybe they think hunters are deaf from firing guns but they're terrible places to hear what someone is saying from a few feet away.
 
F

Floyd Toole

Acoustician and Wine Connoisseur
Ratings
162
#25
"Awkward room boundaries"?

There are two prime areas of "awkwardness" (I like your descriptor, BTW). First, and by far the most awkward, are standing waves at low frequencies. Without any intervention, no two people in a room hear the same bass, and very likely nobody hears really good bass. With bass contributing about 30% of our total impression of sound quality, this is definitely a problem. I devote Chapter 13 to this topic, and there are some interesting solutions involving multiple subs. This is an area where you could exercise your mathematical skills, or use Sound Field Management, in which case a laptop does it for you - sadly it is proprietary, and only available now in JBL Synthesis products.

The second area of awkwardness is broadband first reflections from the sidewalls, floor and ceiling. The difficulty here is that we need information about the loudspeakers in order to anticipate the effects of the reflections. All reflected sounds originate in the far off-axis radiation from the loudspeaker. If the loudspeaker has something resembling constant, or gradually, smoothly-changing, directivity then the reflected sounds can have sound quality that is similar to the direct sound. This is good - when blind tested, listeners like it. The soundstage definitely benefits, the precedence effect works as it should (i.e. localizations are correct),and timbre is not corrupted. Reflected sound helps to fill the deep, octave wide, 2 kHz dip in the center phantom image spectrum heard by listeners in the sweet spot. This is a fundamental flaw in stereo. See Chapter 9.

However, and it is a big "however", many loudspeakers do not behave well off axis. Historically, it was really bad. So, people found that absorbing the reflections improved things. The pros went through a period of a "live end" and a "dead end " in which the loudspeakers were in the dead end, and all off axis sounds were absorbed. One of the most popular monitor loudspeakers of that era was the UREI 811 and its siblings, all of which had absolutely terrible off axis performance. A lot of bad sound was simply turned into heat in thick absorbers.

Calculus won't help you here, but good loudspeakers can do wonders. I spend several chapters of the book discussing the various influences of first reflections. Think about it, if a Stradivarius violin were played in your room, would you feel compelled to absorb most of its sound output? Instead of timbrally rich and room filling, it would sound thin and tiny. If a really good loudspeaker is playing a good recording of a good voice or musical instrument, why would you absorb most of its output?

The common failing of "room treatment" is that if absorption is attempted, only part of the sound is absorbed. One-inch fiberglass board absorbs sound only above about 1 kHz - all it does is attenuate the tweeter output, degrading what might have been a good loudspeaker. Chapter 21 discusses what to use.

Yes, rooms are awkward . . .
 
F

Floyd Toole

Acoustician and Wine Connoisseur
Ratings
162
#26
Chu Gai, my goal is to teach people to design good sounding loudspeakers, then selling good sound is not a problem. It is already beginning to happen. I have heard it happening, and have measured evidence of a gradual improvement in loudspeaker sound quality over the years. The world is a better sounding place than is was in decades past. In most cases it costs no more to build a good sounding speaker, it just requires an understanding of what the target is, and some competent engineering.

Today it should not be a challenge to build a truly excellent "high-end" loudspeaker. But several of them are disappointing because the builders don't understand, believe in or care about, the existing science.

I take great pride in having indirectly contributed to some really fine loudspeakers, some of them very affordable, from our own company and from several non Harman companies. The knowledge is there for all to benefit from.
 
F

Floyd Toole

Acoustician and Wine Connoisseur
Ratings
162
#27
More on distortion:
I forgot to mention this recent study that correlated distortion audibility and listener preference in headphones - no room complications, quiet background, etc.
AES Convention Paper 9118, 2014, "The correlation between distortion audibility and listener preference in headphones", by Temme, Olive, Tatarunis, Welti and McMullin.

It is a serious effort to make sense of distortion measurements and concludes that we are not there yet. They compared THD, IMD, Multitone and non-coherent distortion based on music test signals. The results were very inconsistent, with THD, IMD and multi tone tests offering no useful predictions. The non-coherent distortion test was the best, but even it was not reliable.

As I have discussed earlier, they add to the list of investigators who feel the need for perceptual masking models to be incorporated into the distortion analysis.

Conclusions:
"In conclusion, the perception and measurement of nonlinear distortion is a fascinating but challenging area of research. The linear distortions in headphones are orders of magnitude higher and more audible than the nonlinear ones."
"Finally, this study provides further experimental evidence that traditional nonlinear distortion measurements are not particularly useful at predicting how good or bad high caliber headphone sounds. A more perceptual-based approach for measuring the audibility of nonlinear distortion is warranted."

In summary, we can create new test signals and generate masses of numbers, but we still don't have a distortion analyzer that can tell us what they mean in terms of what we hear.
 
mtrycrafts

mtrycrafts

Audioholic Slumlord
Ratings
2,158 5 6
#28
...
Today it should not be a challenge to build a truly excellent "high-end" loudspeaker. But several of them are disappointing because the builders don't understand, believe in or care about, the existing science.

...
That is truly telling. I see this in many consumer marketplaces. I wonder if this is purposeful or indifference.
 
gene

gene

Audioholics Master Chief
Administrator
Ratings
4,805 25 9
#29
Today it should not be a challenge to build a truly excellent "high-end" loudspeaker. But several of them are disappointing because the builders don't understand, believe in or care about, the existing science.
While I can understand designing a good speaker in a tight budget is challenging, I honestly don't understand how it's possible to build a poor speaker in today's age with such excellent drivers, simulation software, etc. Let's forget the silly designs like placing tweeters on opposite ends of a cabinet in a horizontal driver configuration, or running a 3-way speaker with no crossover on the midrange. But, if you chose SOTA drivers and use high order crossovers in a well braced cabinet with a reasonably narrow baffle, it shouldn't be hard to get a speaker that measures flat on-axis with good off-axis performance too.

I've found some of the big companies tend to go cheap on tweeters and use a driver with a dinky little motor and employ a waveguide to attempt to increase sensitivity at the crossover region. They ignore the fact that the tweeter is still being crossed over too low and you can hear it strain as the volume goes up. Again, this is something missed in most frequency/distortion sweeps but it's clearly audible.

Now let's assume you've got a good budget to buy good drivers. You can get ALL of the data you need from the driver companies or even measure it yourself to ensure the drivers meet spec, don't have nasty resonances and you properly cross them over to be used within their intended BW of operation. This again shouldn't be hard to do. So how are some still missing the target? I suspect there are companies that outsource their designs overseas to a factory that spits out speakers for multiple brands and don't monitor the QC. If the designer doesn't watch their OEM partner like a hawk, it is very likely they will not build the speaker correctly or swap out parts b/c they think its OK to use substitutions even if they are the wrong values, or lower tolerances.

Remember the AV123 brand? They were a prime example of this. Great cabinet work, nice drive units and parts but poor engineering and QC. Almost every speaker sample they sent us for review had to be sent back or fixed here b/c of crossover miswiring or bad tuning. It wasn't until Dannie Richie started helping them out that they were able to make good speakers. Well, until their CEO got caught up in a money scandal and the company went belly up :(

In most cases it costs no more to build a good sounding speaker, it just requires an understanding of what the target is, and some competent engineering.
Agreed but it does cost money if you want a speaker that can sound good at extreme output levels, especially for the lower octaves. I've found most "fullrange" speakers aren't really fullrange below 35Hz or so. A speaker like an M2 is engineered to sound good in small and large spaces and that doesn't come cheap as evident by the $20k+/pair price tag.
 
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highfigh

highfigh

Audioholic Overlord
Ratings
3,304 9 15
#30
Do you think too many are making the decision to build their speakers to look a certain way before they engineer them for sound quality and then decide that "Well, they have some problems, but they sound OK"?
 
TheWarrior

TheWarrior

Audioholic Ninja
Ratings
1,367 14 4
#31
"Awkward room boundaries"?

Awkward would be a reference to any 'open' style home floor plan where a theater is expected to be integrated into a room, that is open to others. Where absorption can treat heavy echo (like in my room, with a 16' gable ceiling) and treat standing waves with thicker, correctly placed panels, or be redirected using diffusors.

Therefore, I am hoping to gain a better understanding the relationship of how room dimensions should be factored in to where the speaker, the listener, and a diffusor/absorber should be located. Hence why I was expecting some complex formula's.

Speaking of awkward, looks like I spoke too soon. The book may end taking 3 weeks for delivery! Guess I'll have to settle for communicating with the author himself! Thank you, by the way!
 
F

Floyd Toole

Acoustician and Wine Connoisseur
Ratings
162
#32
Warrior: Three weeks! Ugh! Amazon says they have one in stock, but they may have lost count.
The placement of diffuser/absorbers for first reflections can be determined by simple geometry - angle of incidence = angle of reflection. For overall room reverberation control, as I just have done in my 13-foot ceilinged living/dining room, is a matter of distributing absorbing material wherever it can be placed without being visually objectionable - it is a living room, not my media room. Use 3-inch panels to capture sound down to the transition/Schroeder frequency. Thin panels are what I call "enemies of good sound" because they just absorb high frequencies. I did it for improved voice communication among aging ears, and it works superbly - my secondary audio system sounds much better too. You cannot control low-frequency standing waves with absorbent panels - they are not thick enough (roughly 1/4 wavelength at the frequency you want to damp - work it out, it isn't practical). Chapter 13 explains the problem and the practical solutions. Low- frequency absorbers that are effective below 100 Hz are almost always membrane absorbers.

Gene: I know you have staked out the "high sound level" territory as your speciality. However the vast majority of people don't want or need it. And anyone in a condo or apartment can't use it if they had it. So, there is plenty of justification for loudspeakers that don't meet your personal standards. Besides, if one starts with a floor stander with less than "killer" bass, at some point it is possible to add sub(s),switch to "small" and play louder than any floor stander, with superior bass for more people in the room. Sounds like a rational system-evolution plan to me.
The "hard" sounding tweeter issue is real, and the real cure is a proper midrange speaker, which has the added advantage of yielding a better directionality vs frequency.
 
3db

3db

Audioholic Overlord
Ratings
3,631 11 12
#33
I just dropped into this discussion, and as my name has been mentioned I can add some clarification.
First: linear distortion refers to amplitude and phase vs. frequency responses, and it is generally constant over a large dynamic range. However, power compression can change things when the voice coils heat up, but that is considered a "linear" effect too in that it happens slowly, not fast enough to modify waveforms. Linear distortion does not modify the waveform of pure tones - single frequencies - but most certainly modifies the waveforms of complex sounds that contain many frequencies - i.e. everything we listen to. But those modifications are essentially constant over a wide range of signal levels.

Non-linear distortion modifies all waveforms by an amount that depends on the non-linear mechanism and how hard it is driven. It is dependent on signal level. The basic problem is that for different amounts of input signal one gets an inappropriate amount of output signal - the input/output relationship is non-linear. We have no way (yet) to quantify the pure non-linearity in terms of what we hear. Instead, we "probe" the non-linear system with simple signals and see what comes out. With pure tone inputs one gets harmonic overtones that should not be there. Comparing the unwanted harmonics to the wanted (fundamental) signal gives us a percentage harmonic distortion. Almost everyone in the world does this kind of measurement (including the NRC). It tells us something about the system but the numbers do not correlate at all with what we hear in broadband music. Total harmonic distortion that is zero is what we are after. Any amount above zero is undesirable, but we may or may not be able to hear it in music - unless it is very high. Engineers designing transducers find it useful in that it reveals something about the non-linear mechanism that is misbehaving. Because of perceptual masking the signal that causes the distortion prevents us from perfectly hearing lower harmonics, so an improved measure boosts the level for increasingly higher harmonic numbers.

The next step is to use a more complicated signal, twin-tone or multi-tone combinations that generate both harmonic and intermodulation distortion components. Because many of the intermodulation products are well separated from the driving frequencies, especially those lower than the driving frequencies, they are less masked and more easily heard. Hence the common belief that intermodulation distortion is worse than harmonic distortion. Really, they both come from the original problem - the non-linearity - but are simply different ways of trying to quantify it. In the end, again because of perceptual masking (more input signals more masking) this too fails to correlate well with what we hear in music. When the frequency range is subdivided as in two-, three- and four-way systems the scheme falls apart because different driving signals go to different transducers and the numbers cannot be compared between different loudspeakers. However, it is a very good way to demonstrate the advantage of multi-way loudspeakers.

At the present time the best possibility for a useful measurement of non-linear distortion is one that includes models of the key perceptual mechanisms. Because we cannot hear all of the distortion products that are measured, the measurements we have cannot be correct. We have to try to predict what is and is not audible, and that is a massive research project. In the meantime we can all be grateful for perceptual masking - it allows us to think that a lot of non-linear products sound just fine. LPs generate masses of all kinds of distortion and we enjoyed them for years.
I have to order your book on this and try to revive my brain again after have stepped away from electrical engineering for 30 years. :)
 
gene

gene

Audioholics Master Chief
Administrator
Ratings
4,805 25 9
#34
Gene: I know you have staked out the "high sound level" territory as your speciality. However the vast majority of people don't want or need it. And anyone in a condo or apartment can't use it if they had it. So, there is plenty of justification for loudspeakers that don't meet your personal standards. Besides, if one starts with a floor stander with less than "killer" bass, at some point it is possible to add sub(s),switch to "small" and play louder than any floor stander, with superior bass for more people in the room. Sounds like a rational system-evolution plan to me.
The "hard" sounding tweeter issue is real, and the real cure is a proper midrange speaker, which has the added advantage of yielding a better directionality vs frequency.
Well actually I try to appeal to all audiences but every now and then I like to test drive a Porsche or the Lexus LFA instead of just driving a Civic ;)

As you know, we always preach multiple subs so we are on the same page. I just don't like seeing junk parts put in expensive or "prestigious" speakers or hamster I4 engines in so called "sports" cars :D
 
TheWarrior

TheWarrior

Audioholic Ninja
Ratings
1,367 14 4
#35
Warrior: Three weeks! Ugh! Amazon says they have one in stock, but they may have lost count.
The placement of diffuser/absorbers for first reflections can be determined by simple geometry - angle of incidence = angle of reflection. For overall room reverberation control, as I just have done in my 13-foot ceilinged living/dining room, is a matter of distributing absorbing material wherever it can be placed without being visually objectionable - it is a living room, not my media room. Use 3-inch panels to capture sound down to the transition/Schroeder frequency. Thin panels are what I call "enemies of good sound" because they just absorb high frequencies. I did it for improved voice communication among aging ears, and it works superbly - my secondary audio system sounds much better too. You cannot control low-frequency standing waves with absorbent panels - they are not thick enough (roughly 1/4 wavelength at the frequency you want to damp - work it out, it isn't practical). Chapter 13 explains the problem and the practical solutions. Low- frequency absorbers that are effective below 100 Hz are almost always membrane absorbers.

Gene: I know you have staked out the "high sound level" territory as your speciality. However the vast majority of people don't want or need it. And anyone in a condo or apartment can't use it if they had it. So, there is plenty of justification for loudspeakers that don't meet your personal standards. Besides, if one starts with a floor stander with less than "killer" bass, at some point it is possible to add sub(s),switch to "small" and play louder than any floor stander, with superior bass for more people in the room. Sounds like a rational system-evolution plan to me.
The "hard" sounding tweeter issue is real, and the real cure is a proper midrange speaker, which has the added advantage of yielding a better directionality vs frequency.

These panels actually have a 'membrane layer' that is not given any quantifiable data as to its effectiveness, just the claims of improved function. I think my furniture, namely a 6' diameter foam 'bean bag' chair, are doing the real work here. Because of my open floor plan, that chair is effectively in a different room. Which it needs to be because with in 45 degrees or so of the nearest speaker, it creates a black hole for sound.

Anyway, I hope to apply all of this to a truly custom built home theater. As in, one that I built the structure for, and designed a specially sized room to be housed with in. My wood shop, occupying the downstairs, of course!

Thank you again for the wisdom, and I look forward to learning from your book!
 
D

davidrmoran

Audiophyte
Ratings
2
#36
Toole's book is available online as a googledoc, but I think it essential (and of course more ethical) for anyone interested to pay for it, however it takes to get a copy. It is a must-read if anything is in audio for the serious layperson. I called it 'masterful' in LinearAudio magazine a year ago even while taking exception with some historical contexts and uninterests. It is, frankly, like reading Steinberg or Rosen on classical music, Broadbent and others on wine, and Hughes et alia on art, to name only those where I have some experience: a headshakingly impressive experience from a master.

There is a third area of 'room awkwardness' related to reflections, the lower midrange. It is as important as any, if not more. Admittedly perhaps subtler, given ear sensitivities. FT knows all of this and does get into it in his book, although in my and others' view he scants it to some extent. The (Roy) Allison effect, as it is sometimes known even though it was presaged before Allison's 1970s real-world room measurement papers by earlier researchers and also elaborated afterward (notably by B&W's Glyn Adams),shows that when the distances to the three near boundaries --- front wall, sidewall, floor --- are similar, the result in almost all domestic situations will be a notch in the lower midrange (90-350Hz or so). Btw the floor is not privileged, gravity having no effect. And it does NOT have to do with first reflections only, but tangential and oblique as well; see the well-known Olson cubical drawing of sound source near corner. Allison misleadingly termed this an LF effect, although it's typically higher than most of us can sing, hence my term lower midrange, as in looking at a musical score.

The solution is to design systems such that the driver(s) covering this range are not only multiple (a recent happy solution) but also forced to be staggered wrt to the three near boundaries, preferably with one distance close to a boundary, like the floor or front wall. FT says the AE suckout is broad and not so frequency-specific, although that's not what Allison and many others, including myself, have found from our measuring and listening. It is altogether audible, and sometimes initially euphoniously thinning, yes, but not natural or accurate over time to an experienced ear. (See amusing Gordon Holt Stereophile review mid-1980s of the Allison Nine, to the effect that 'I eventually came to realize that all other speaker systems have been doing the lower midrange wrong', etc.)

As for distortions and linearity/nonlinearity, I suggest thinking to first order of linearity as having to do with the y axis rather than the x axis. More important, there are hoary demonstrations showing how profoundly unimportant these distortions are. Dr. Mark Davis (1978 High Fidelity magazine article) and also others have described a well-known Amar Bose experiment at MIT using an audio chain comprising driver, mike, amplifier, second gain stage, and headphones. He drove the driver with various signals, soft to very loud, but kept the levels at the listener the same. Guess what? Distortions become audible only at near-destruction overdriving. (Email me, consulting LinkedIn or F/B, for a copy of this fascinating article on speaker radpat and what we do and do not hear; Davis works at Dolby.)

A second (anecdotal) datapoint was the comment from the great musical acoustician Arthur Benade to Allison and Edgar Villchur, after publication of their AESJ paper showing no audibility of Doppler distortion from hifi loudspeaker systems deployed at typical levels. Benade pointed out to them that this finding also surely meant that the other bruited worrisome distortions (TH, IM) must also be inaudible short of gross overdriving.
 
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Montucky

Montucky

Full Audioholic
Ratings
202
#37
Well actually I try to appeal to all audiences but every now and then I like to test drive a Porsche or the Lexus LFA instead of just driving a Civic ;)

As you know, we always preach multiple subs so we are on the same page. I just don't like seeing junk parts put in expensive or "prestigious" speakers or hamster I4 engines in so called "sports" cars :D
That's why I appreciate your work so much. Sure, I love seeing how the Status Acoustic 8Ts measure, and enjoy reading about them, but when my budget is 1/10th of that, I appreciate the honesty I see in your other reviews to help me make my purchasing decisions. You guys have really helped guide me toward the most bang for my buck, and helped me steer clear of equipment that just doesn't hold the same value.

Just like you said, it'd be upsetting to see hamster powered engines in "sports" cars. Lots of stuff like that on the audio side of things for sure. Cough cough...Bose...cough cough.

Perhaps the industry isn't crazy about blatant honesty because not everybody else is on board, and consumers overwhelmingly fall for the exaggerated numbers. When you see brand X receiver state 100 Watts/channel, and brand Y state 50 Watts/channel, which do you think the average consumer is going to pick? Even if Brand Y's stated wattage is totally accurate and realistically outputs power far superior to brand X's inflated numbers.

So I guess until there's an industry standard that ALL manufacturers have to stick by, we'll keep seeing these sorts of games. Thanks for watching out for us though, Gene!
 
DukeL

DukeL

Audioholic Intern
Ratings
24
#38
My apologies for being late to the party.

I have immensely enjoyed Floyd Tooles's input here. He mentioned masking... I wonder if the disproportionate audibility of amplifier crossover distortion is because masking doesn't work well in the time domain, and since crossover distortion happens at the zero point as the waveform crosses from positive to negative phase, it is therefore "unmasked"?

I have a worn copy of Sound Reproduction sitting within arm's reach of my computer, and have tried hard to use many of the principles and properties of acoustics and psychoacoustics that it lays out. Not having a formal engineering background (I'm among the 5 out of 4 people who have trouble with math),it has been extremely valuable to me. Dr. Toole, I can honestly say that my speakers suck less because of you.

This statement especially caught my attention:

"If the loudspeaker has something resembling constant, or gradually, smoothly-changing, directivity then the reflected sounds can have sound quality that is similar to the direct sound. This is good - when blind tested, listeners like it. The soundstage definitely benefits, the precedence effect works as it should (i.e. localizations are correct),and timbre is not corrupted."

Since we're on the subject of reflections, wonder if I could bounce something off you... namely, the possibility of a correlation between "listening fatigue" (or lack thereof) and the spectral balance of reflections?

...So, the ear/brain system is constantly classifying incoming sounds as either new sounds or reflections (repetitions of a recent sound),as part of the Precedence Effect mechanism. My understanding is that the ear/brain looks primarily at the spectral balance of those incoming sounds in order to decide which they are. When the spectral balance is the same as, or close to, the first-arrival sound, all is well. But what about when the spectral balance is off, as with a loudspeaker that has poor off-axis sound? Now (so I speculate) the ear/brain system has to work a bit harder to correctly classify this as a reflection because it's not an obvious match for a recent sound. Is it possible that, over time, this increased "cpu usage" causes the processor to overheat, and listening fatigue (or sometimes literally a headache) results? Not saying that this is the only cause of listening fatigue, but wondering if it might be one possible cause.

Thanks for your time, and for any insight you care to share.

Duke LeJeune
AudioKinesis
 
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F

Floyd Toole

Acoustician and Wine Connoisseur
Ratings
162
#39
Hello Duke,
You raise a good point. I know of no definitive answer to the issue of listener fatigue, one reason being that to some extent it depends on the listener. We are all different in some respects, more or less tolerant of the multitude of parameters the constitute music reproduction. Loudness is an obvious factor. It also depends on what you are listening to. I personally have found loudspeakers with resonant colorations to be especially irritating - fatiguing if you like. Others seem to be more tolerant - until they hear something better and then they too can be annoyed. Humans are adaptable, up to a point.

The matter of the breakdown of the precedence effect is one possible contributor, because instead of spectrally similar reflections being suppressed in sound localization - leaving only an awareness of the position of the first arrival - the reflections become individually localizable sound sources at the points of reflection. Maybe the "cpu" does get tired trying to analyze these abnormal sounds :)

Because of the extreme simplicity of stereo (a directionally and spatially deprived format) there are some kinds of recordings that appear to benefit from a bit of added spaciousness. An instrument hard panned L or R is a mono signal, emerging from a tiny point in space - not realistic. We need more channels and loudspeakers. But don't hold your breath. The movie folks figured this out decades ago, but not the music industry.

Floyd
 
jonnythan

jonnythan

Audioholic Ninja
Ratings
480
#40
Why don't standard measurement suites test for dynamic compression at high volume levels? I haven't looked at a review in a while, and I'm just throwing this out there, but that seems to be a big limitation of many speakers, particularly smaller speakers. I'd like to see quantification of how much a speaker struggles to produce high dB when called for.
 

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