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Is Toole and Olive's Spinorama model incomplete and limited?

Neuro

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To my knowledge, Harman's Spinorama related double-blind studies have not been reproduced and confirmed by other independent researchers in other listening rooms.

Can the findings be extrapolated to rooms other than Harman's specific listening room?

What are the acoustic properties of the room in which the Spinorama model is created? Absorbent surfaces, reflective surfaces, etc.?
Exact size, speaker position and listening position?. Are passive comparison speaker positions and relative acoustic properties always the same?

HARMAN.png

Is this a typical listening room?

In the study below, Sean Olive admits that the method is limited to this room and mainly box speakers. No other rooms have been evaluated. 70 different box speakers are the foundation of the study. One dipole speaker, Martin Logan, was tested.
Floyd Toole has pointed out on several occasions that the only dipole speaker in the study, Martin Logan, measured poorly in the physical and psychological dimensions. Even the direct sound was strongly deviant.
The room is clearly optimized for box speakers. Dipole speakers and omnipole speakers will not create optimal reflections in this room.

For me, as an amateur at speaker measurements with some knowledge of how the brain reacts to early broad-spectrum reflexes behind the evaluated speaker from the other speakers, it is not surprising that in the physical dimension destructive interferences occur with the direct sound which cannot be compensated for in the brain in the neurophysiological dimension.

I foresee great potential in a completed general spinorama model where each unique room's size and acoustic properties are factored into the calculation to be able to predict how each spinorama examined speaker will sound in each unique listening room. The measurement results must be supplemented by taking into account some important crucial neurophysiological and neuropsychological aspects of how we hear in rooms in the calculation to create a complete spinorama algorithm.
Completing the algorithm with neurophysiological and neuropsychological data is not particularly difficult.

A Multiple Regression Model for Predicting Loudspeaker Preference Using Objective Measurements: Part II - Development of the Model
Sean E. Olive, AES Fellow

 

abdo123

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I don’t think what you’re requesting is of value to either the consumer or the manufacturer.

There will never be room-specific products, the manufacturing cost will be insane and the size of the market will never warrant such a thing.

And from the consumer side of things it’s better to just get a speaker with high output and high linearity and just use room correction and / or room treatment to fix issues caused by the room.
 

GXAlan

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I think the overall consistency with stuff that sounds good as predicted by the spin correlates with stuff that scores well on the preference score.

As you note, planars, omnipolars, and even in wall speakers won’t fully be captured by the spin. Things that measure poorly and have low preference scores may still be preferred by specific people in specific rooms with specific music.

For a audiophile with multiple systems, it probably does not make sense to have multiple speakers that all go for the highest Harman preference. Makes sense to have different flavors.

Additionally, Sean Olive in his own blog has said that the bass boost preference seen with headphones also is seen with well design good dispersion loudspeakers.

In my opinion, the spin / preference score is very good at predicting good box speakers.

The spin is very helpful in using science to determine the optimal room position of a speaker but a low preference score in a non box speaker doesn’t translate into the same thing as a low preference score in a box speaker.
 

DanielT

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#68 in the thread:


I-or:

"4. Olive's formula is developed in Harman's listening room, which differs a lot acoustically from many modern and sparsely furnished (i.e. undamped) Swedish homes. If you, for example, place the loudspeakers relatively close to the side walls in a room with an open-plan solution and high ceiling height (i.e. long reverberation time), high directivity even at relatively low frequencies will be absolutely decisive. However, the agreement for typical Swedish listening rooms and setups will probably be quite good.

5. Toole and Olive never seem to have bothered to design/select/correct a low distortion speaker with good frequency response and dispersion to isolate the distortion but have had the impact of the distortion drowned out by the more potent effects of frequency response and dispersion when seeking correlation between different parameters. In addition, the situation has been worsened by taking psychoacoustically weighted distortion measures rather lightly. It is also my experience that precisely distortion of "normal" dignity at medium sound pressure levels is something that the average listener values as quite unimportant, while for sensitive individuals it is absolutely crucial in some cases (compare e.g. with color flicker for DLP projectors)."

(if you read #68 forget about simulations, that's I-or's reply to another post and has nothing to do with Toole)

But overall I know he I quoted, I-or, like Toole and Olive's work/ research. :)

Of course, distortion in speakers can become audible and annoying, see:

 
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DanielT

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I don’t think what you’re requesting is of value to either the consumer or the manufacturer.

There will never be room-specific products, the manufacturing cost will be insane and the size of the market will never warrant such a thing.

And from the consumer side of things it’s better to just get a speaker with high output and high linearity and just use room correction and / or room treatment to fix issues caused by the room.
Fully tailored to fit a specific room, probably few would pay for that. But a little more generally, for example speakers that are designed to be mounted in walls, or hung on walls, there is most likely a demand for them. IKEA doesn't build speakers because they think it's fun. They do it to sell them and make money::)


Edit:
If you want speakers precisely adapted to your listening room, you probably have to build them yourself. But it is not the large speaker user mass of people who do such a thing. It's a fairly small hobby, DIY speakers.:)

Line speakers that go from floor to ceiling, for example. I don't even know if such can be bought on a commercial basis.
 
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Cars-N-Cans

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I foresee great potential in a completed general spinorama model where each unique room's size and acoustic properties are factored into the calculation to be able to predict how each spinorama examined speaker will sound in each unique listening room. The measurement results must be supplemented by taking into account some important crucial neurophysiological and neuropsychological aspects of how we hear in rooms in the calculation to create a complete spinorama algorithm.
Completing the algorithm with neurophysiological and neuropsychological data is not particularly difficult.
I would say the room influences and targeted steady-state responses are the onus of the end user and not the speaker manufacturer. Really their job is to get the frequency response, directivity, control of resonances, distortion, etc. in line so the speaker delivers a predictable and linear response and conforms to its specifications (if any are even provided). The selection of the speaker is then based on what type of listening environment and preferences you have. Trying to pull the room into the equation would be adding far too many variables to be reliably controlled or simulated. Rather selections of speakers with different performance criteria are provided by manufacturers to meet the expected demands of consumers. Having good data on various listening environments is probably quite crucial to that, but I don't think there is any one measurement that could encompass every situation, and the end result will be influenced by the room and application. For myself being a terminal couch potato, my setup is hooked to my PC and used in the nearfield, so the typical predicted "-1 dB/octave" in-room response goes out the window since I'm in the direct sound field of the speakers. But I agree in that it would be nice if some form of simulation software or generalized algorithm could be developed that would help in speaker selection and system setup with respect to the room. Another thing that would be nice would be to have a more clear picture of how the in-room response is influenced by differing parameters such as the varying RT with frequency and the dispersion pattern of the speaker.
 

fpitas

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If you have the money to afford the best, an installer comes to your house and not only installs the speakers, but performs any necessary EQ that may be necessary, and will suggest and install room treatments.

I can't conceive of how one would approach room specific speakers. There might be a good quasi-snake-oil market, though. Have piles of impenetrable scientific sounding jargon, and sell them bargain-basement stuff at a vastly inflated price. Laugh all you want, but Bose got quite wealthy in just that way.
 
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Geert

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People are making this much to complex. The outcome of Toole's research is that on average people prefer a speaker with a flat anachonic frequency response and smooth changing directivity, with a bit of wiggle room in the lows and highs to tune to personal preference. Does this come as a surprise? Does someone expect these findings to be highly dependent on the listening room? And yes, they're limited to box speakers. Being 99,99...% of speakers out there.
 

ctrl

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Is Toole and Olive's Spinorama model incomplete and limited?

You might not want to call the "preference score" developed by Olive "spinorama model", otherwise some might conclude that the spinorama, i.e. the CTA-2034-A standard, is "incomplete and limited" - which is not the case.
 

fpitas

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You might not want to call the "preference score" developed by Olive "spinorama model", otherwise some might conclude that the spinorama, i.e. the CTA-2034-A standard, is "incomplete and limited" - which is not the case.
Good point. The spinorama model procedure has nothing to do with the preference score. That kind of makes this whole thread moot.
 

PierreV

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I foresee great potential in a completed general spinorama model where each unique room's size and acoustic properties are factored into the calculation to be able to predict how each spinorama examined speaker will sound in each unique listening room.

Isn't that a bit missing the forest for the tree?

As consumers we don't care about predictions, we care about actual measurements. To "fix" those measurements to a standard, or our own tastes, we can use DSP either automatically or by tweaking.

As a manufacturer, I would simply like to produce speakers that are, on average, preferred by the majority of users.

The prediction of a simple room response is computationally intensive. Complex rooms with furniture are not practically doable, which is why the response is typically measured and then adjusted.

Completing the algorithm with neurophysiological and neuropsychological data is not particularly difficult.

And, reaching a consensus is even easier as it is constantly demonstrated on this site. ;)
 

ctrl

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The spinorama model procedure has nothing to do with the preference score.

Yes, we should make a clear distinction between

- "Spinorama", i.e. the CTA-2034-A standard, as the measurement method for in-room (home) loudspeakers

- and the double-blind studies on the listener preference of loudspeakers

- and the evaluation model (algorithm) which predicts a "preference score" using CTA-2034-A measurements and the listener preference studies and tries to establish a correlation.

The heading should rather read:
Is Toole and Olive's "preference score" incomplete and limited?
Then you'll find that this topic has been discussed to death several times here on the forum ;)
 

fpitas

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Yes, we should make a clear distinction between

- "Spinorama", i.e. the CTA-2034-A standard, as the measurement method for in-room (home) loudspeakers

- and the double-blind studies on the listener preference of loudspeakers

- and the evaluation model (algorithm) which predicts a "preference score" using CTA-2034-A measurements and the listener preference studies and tries to establish a correlation.

The heading should rather read:
Is Toole and Olive's "preference score" incomplete and limited?
Then you'll find that this topic has been discussed to death several times here on the forum ;)
Yes. The OP has some fundamental misunderstandings.
 

Mnyb

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If you seen Erins adio corners videos , he has compared the PIR of the measurement sets in CTA-2034-A and found great agreement with his own rooms above the transition frequency . So CTA-2034 can predict behavior in "typical rooms" .

I would not comment on the preference score there are other treads :)
 

DanielT

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Design philosophy regarding FR and speakers. Here about Gundry dip (BBC dip?). I suspect it was Sean Olive who wrote that post::)

Screenshot_2022-08-31_143625.jpg




Tips for those who are interested. Here a long video with Sean Olive (I just found it now I haven't seen it).

 

fpitas

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Design philosophy regarding FR and speakers. Here about Gundry dip (BBC dip?). I suspect it was Sean Olive who wrote that post::)

View attachment 227794



Tips for those who are interested. Here a long video with Sean Olive (I just found it now I haven't seen it).

Which is to say, smooth directivity is key. That agrees with common sense, unless you listen in an anechoic chamber.
 

ctrl

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If you seen Erins adio corners videos , he has compared the PIR of the measurement sets in CTA-2034-A and found great agreement with his own rooms above the transition frequency . So CTA-2034 can predict behavior in "typical rooms" .
Yes, the PIR in the CTA-2034-A standard is the parameter most likely to be objected to, as it generalizes the most.

The predicted in-room amplitude response (PIR) represents a gross simplification of reality. But the authors of CTA-2034-A were aware of this:
By making some simplifying assumptions about the listening space, the data set described above permits a usefully accurate preview of how a given loudspeaker might perform in a typical domestic listening room.

Obviously, there are no guarantees, because individual rooms can be acoustically aberrant. Sometimes rooms are excessively reflective (“live”) as happens in certain hot, humid climates, with certain styles of interior décor and in under-furnished rooms. Sometimes rooms are excessively “dead” as in other styles of décor and in some custom home theaters where acoustical treatment has been used excessively.
and explicitly it says (emphasis by me):
This form of post processing is offered only as an estimate of what might happen in a domestic living space with carpet on the floor and a “normal” amount of seating, drapes and cabinetry. Reverberation time would typically be in the vicinity of 0.4 s and relatively constant with frequency over most of the frequency range.
Source: CTA-2034-A Standard, 2015
 

dominikz

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If you seen Erins adio corners videos , he has compared the PIR of the measurement sets in CTA-2034-A and found great agreement with his own rooms above the transition frequency . So CTA-2034 can predict behavior in "typical rooms" .
I also see amazing agreement between theoretical PIR and practical steady state in-room response in my experiments, here's a couple examples of measurements taken in different rooms and different listening distances:
index.php

(source 1)
index.php

(source 2)

In short, from my investigation I'd say there is very good agreement between the spinorama (CTA-2034-A) model prediction and most 'small' listening rooms above the transition frequency.
Below the transition frequency room modes dominate, but good results can still be achieved by use of EQ, loudspeaker placement and use of subwoofers (ideally multiple ones).

Can the findings be extrapolated to rooms other than Harman's specific listening room?
To my understanding an effort has indeed been made at some point to test whether loudspeaker preference is consistent across rooms - the book refers to the 1995 article "The Variability of Loudspeaker Sound Quality Among Four Domestic-Sized Rooms" by Olive et all, and 2006 article "Loudspeakers and Rooms for Sound Reproduction-A Scientific Review" by Toole.

Hope this helps!
 

Kvalsvoll

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I foresee great potential in a completed general spinorama model where each unique room's size and acoustic properties are factored into the calculation to be able to predict how each spinorama examined speaker will sound in each unique listening room.
To do this you need the complete measurement set from the speaker - a 3D scan with sufficient resolution covering all sound radiated from the speaker in all directions. So no need for a new model.

Then you need the acoustic properties of the room, including placement of speakers and listener. This is where this stops, for all practical purposes.

If you have all the data, it is then possible to convolve the speaker response with the room, and get data similar to what you get from in-room measurement. It can also be possible to use this as a transfer function and convolve this with music samples, and get a sample of how the sound will be in-room. This data can give some information, if you know how to read into measurements; hint: the frequency response is not what you are looking for. As for the sound sample, there is the obvious problem - how to listen to this, and preserve this speaker-room combinations sound character, without adding a new layer of sound artifacts from the reproduction system.

A model is a simplification of reality, and the best model is the one that is as simple as possible, while still managing to show the properties that are of interest. As such, this spinorama model seems to work quite well, if the goal is to predict in-room frequency response. To get significantly better accuracy, requires too much effort, it simply does not pay off.

A different aspect of this, is that the tonality of the room-speaker combination is not what the frequency response shows, that is only one part of the whole story here. Also, it will be of interest to know something about the sound character of the system, like, does it sound soft and smooth and dull, or is it sharp and focused and lively. This does not show in the frequency response.

A better and more reasonable approach is to look at the measurements of the speaker, both on and off axis responses, and compare to other speakers that you have heard. Regardless of room, the inherent sound character of the speaker will always be present.
 
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