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Genelec 8030C Studio Monitor Review

I'm specifically talking about computed preference scores based on research by Sean Olive and Todd Welti (so is @Deluxillo, I think).
Thank you for sharing this so interesting information, I passed a good time reading Olive et al. article.

I had to search many audio related terms which was very formative, some of them were confusing when reading at first time.

My only criticism to Olive’s model is the statistical analysis and the whole model based on linear regression. The problem of which maybe in the core of many debates here in ASR.

Linear regression methods tend to find a minimum (optimal metric approach) distance to a hypothetical idealized function that describes a real system.

The problem of this methods regarding to human taste is the non-unicity of the solution in real world, which demands to non-linear models that give more than one solutions.

I explain this more simply by the now infamous “tomato sauce theorem”

Some decades ago, a company producing a popular ketchup sauce, engaged a team of researchers conducting a study of which variables could predict the very best and most accepted ketchup recipe.

After making independent variables as acidity (pH), sweetness (glucose concentration) and others, they conclude one linear model, as Olive did, based on a first round taste of lots of different sauces and punctuation about variables perceived by the subjects, and the ulterior regression model to weight the coefficient.

The real marketing of the predicted ketchup was very poor with respect to expectancy of the brand: less then 6/10 satisfaction.

The experts thought deeply and made new studies with the same volunteers, and came to a surprising (not today but at the epoch) conclusion: they were no one single solution, but a series of clusters of people in which different models were highly satisfying among subgroups: some models weighed more on acidity variable, other on texture and so forth…

As a conclusion, 3 or 4 different sauces was revealed to give a global 9 to 10/10 satisfaction and no single model scored beyond 6/10, revealing the non-linear behavior of human preferences.

Possibly this applies to Olive model and other Harman curves, as I can saw they are all based in the ancient linear supposition of predictability. Olive himself noticed that some underlying dependence between variables could lead to model limitation, but I was surprised that he wrote linear regression as a strong trustable statistical analysis (which it is, applied to many systems), whereas barely all industries today produce various subtypes of same product (see soda companies for example) in order to match cluster-like preferences of consumers.

But still a good and formative article, ASR is providing me a lot of new knowledge, most of which is far from my economic possibilities to test :cool:

POST EDITING: I now reading about a family of curves that tend to match different tastes, classifying the listeners in subgroups: sorry, I begun with ancient articles. My critique is only applied to the original Olive et all model and early Harman curve.
 
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I figured the problem wouldn’t be in their measurements haha

Then I don’t understand how measuring the vertical frequency results in such a high total score. There must be some concept I’m missing. Thank you very much for your explanations
Copied from the conclusions of Olive et al. study:

“In this study, loudspeaker directivity by itself
had little predictive power of listener preference. It is
unclear what the ideal directivity of the loudspeaker
should be, except that it should be smooth”

If you want to read it at complete:


The paper is about loudspeakers, don’t worry about the title mentioning headphones
 
I think the only conclusion from the research was that you want a smooth directivity (because of how it affects the reflections).
 
I think the only conclusion from the research was that you want a smooth directivity (because of how it affects the reflections).
They were various variables which contributed to the model:

“The independent variables that predict loudspeaker
preference rating include measures of the amplitude deviations in the on-axis response, the predicted-in-room response and the low frequency response.
Each sound component in the model has equal importance
in predicting preference”
 
They were various variables which contributed to the model:

“The independent variables that predict loudspeaker
preference rating include measures of the amplitude deviations in the on-axis response, the predicted-in-room response and the low frequency response.
Each sound component in the model has equal importance
in predicting preference”
Yes, that's what I'm saying. Smooth directivity means your off-axis response matches your on-axis response and thus your predicted-in-room response.
 
Yes, that's what I'm saying. Smooth directivity means your off-axis response matches your on-axis response and thus your predicted-in-room response.
Nope: the amplitude deviation in on axis response takes also into account.

Is a measure that take the average of absolute value of the difference between the recorded amplitude of each 1/20 octave band and a reference 200-400 Hz band.

Is a central measure that correlates the flatness of the on-axis frequency curve.

According to the model, it independently contributes to the predicted preference as well as smooth directivity.
 
From another thread, but bearing directly on the use of the 'preference rating':
I just dipped into this thread and have a request: please, please stop putting any reliance on the calculated "scores". Learn to interpret the spinorama curves. That will have to do until we have an "educated" AI version of sound quality prediction. The ratings that were calculated by the Harman research group were done to prove a scientific point, and that done, they ceased to be used even by the people who created them. We rely on visual interpretations of the family of curves.
 
Nope: the amplitude deviation in on axis response takes also into account.

Is a measure that take the average of absolute value of the difference between the recorded amplitude of each 1/20 octave band and a reference 200-400 Hz band.

Is a central measure that correlates the flatness of the on-axis frequency curve.

According to the model, it independently contributes to the predicted preference as well as smooth directivity.
Lets take a step back. Your off-axis response together with your on-axis response is responsible for your in-room response. Generally speaking you want those two to match to get a good in-room response. You can't separate the directivity from your in-room response, because reflections are a major factor there. In an ideal loudspeaker you want your on-axis response to be perfectly flat (anechoic) with smooth directivity so that your off-axis sound and thus the in-room response follows along nicely and create a smooth downward slope.


There are
From another thread, but bearing directly on the use of the 'preference rating':
Plus this of course.
 
From another thread, but bearing directly on the use of the 'preference rating':
Absolutely agree; as I mentioned before, Olive methods were intended to predict average tastes and himself recognized limitations of the model (as any scientist should do, he’s an excellent researcher).

For any listener, individually, some variables may take importance more than others. The merit of Olive et collaborators was to provide a well accurate and comprehensive model in which the industry and average consumer can trust with some interval of confidence.

Obviously the meticulous comprehension of measurements and also of ourselves in relation to measurements will provide a better model. But only applicable to one subject and take longtime to learn: statistical models are fast, cheap and capture huge proportion of population
 
Lets take a step back. Your off-axis response together with your on-axis response is responsible for your in-room response. Generally speaking you want those two to match to get a good in-room response. You can't separate the directivity from your in-room response, because reflections are a major factor there. In an ideal loudspeaker you want your on-axis response to be perfectly flat (anechoic) with smooth directivity so that your off-axis sound and thus the in-room response follows along nicely and create a smooth downward slope.


There are

Plus this of course.
Of course, I wrote “varios parameters (or variables). But you can have a non flat response and a smooth directivity if the variation of the on-axis response with the direction is smooth enough.

Both variables were tested and their inter-correlation found small enough to not interfere with the independency assumption.

You can read the article, they are not my opinions: just the researchers findings
 
Of course, I wrote “varios parameters (or variables). But you can have a non flat response and a smooth directivity if the variation of the on-axis response with the direction is smooth enough.

Both variables were tested and their inter-correlation found small enough to not interfere with the independency assumption.

You can read the article, they are not my opinions: just the researchers findings
Yes and in that case your in-room-response will also be pulled down in addition to your on-axis response. On-axis response + directivity = in-room response.
 
Yes and in that case your in-room-response will also be pulled down in addition to your on-axis response. On-axis response + directivity = in-room response.
This remember me constantly that I have to buy a calibration microphone and start putting in practice the bunch of theory I read :)

Returning to the reality, the WiiM Ultra measurement section is fun but has some random behavior (probably related to the use of smartphones mic) and the proposed corrections have some nonsense parameters.
 
I just looked in to this thread and I see the same old misinterpretations. I am winding up writing the 4th edition of my book "Sound Reproduction" where all of this is discussed in detail. Sean Olive and Todd Welti will be contributing chapters to this one. Let me remind the group of a few important facts:
1. the spinorama post processing is aimed at estimating the sounds that arrive at a listener, not the sounds that leave the loudspeaker - not all are strongly relevant to our perceptions.
2. The spinorama data set can estimate a room curve above the transition frequency with useful accuracy. It is almost entirely the "early reflections" curve - i.e. off-axis sound, the direct sound only shows itself at very high frequencies.
3. Because we can estimate a room curve does not mean that the room curve has special importance - even though embodied in it are all sounds heard by a listener. Two ears and a brain are not the same as an omni microphone!!!!!!!! Steady-state room curves show irregularities that humans perceive as normal room spaciousness. We adapt to rooms and "listen through" much that is seen in room curves.
4. The room curve is a "result" not a "target". Without comprehensive anechoic data on the loudspeaker it cannot be interpreted. NOTE: below the transition frequency the room curve becomes the definitive measure because loudspeakers tend towards omnidirectIonality at low frequencies. At these frequencies the room is the dominant factor.
5. The main reason why smooth curves are important, and why similarity among the various spatially averaged spinorama curves is important is that these are evidence of a lack of resonances. Resonances are the primary cause of degraded sound quality and low-Q resonances visually appear as spectral trends, not little spikes or bumps which are also important of course. Such low-Q trends are extremely audible, having detection thresholds of the order of 1 dB or less.
6. Although it is logical to think that reflected sounds should have timbral signatures similar to the direct sounds, it may be more important that both be free of resonances.
7. My first 1986 JAES paper showed that all highly rated loudspeakers had flat and smooth on-axis - direct sound - frequency response. This observation has persisted through hundreds of double-blind listening tests when I was at the National Research Council of Canada and during my tenure at Harman. Olive's correlations confirmed it in a different way, when trained listeners "drew" frequency responses of what they thought they heard - they drew the direct sounds, the on-axis response, not room curves.
8. If you should be fortunate enough to have loudspeakers with flat and smooth on-axis response why would you change it by equalizing a room curve? If a room curve has an unappealing shape, it is most likely because of off-axis - i.e. directivity - problems and equalization cannot change that. The solution is a better loudspeaker.
9. Now that spinorama data is widely available - thanks Amir , Erin and a few courageous manufacturers - customers can choose loudspeakers wisely.
10. Spinorama data predicts neutral, highly rated loudspeakers, with great precision. Poorly rated loudspeakers are also predicted with great precision. The challenge for consumers is the vast middle ground of loudspeakers that are almost good, that have only one or two small issues. Smart interpretation of the data can tell you whether EQ based on the anechoic data can be beneficial, or not. The room curve is not trustworthy data even though there are for-profit companies promoting its importance - they don't make loudspeakers, they sell promises. Note that all of them have "target" curves, but if you don't like the sound, you can change the target curve. Think about it . . .
11. Buy the most neutral loudspeaker you can find or afford, address the bass problems you almost certainly will have in small listening rooms - it is about 30% of one's overall impression of sound quality!. Multiple subs are remarkable, and they don't need to be large because at long wavelengths in small rooms they sum pressure, not power. Then use tone controls to compensate for program variations and/or personal preferences including, perhaps, tasteless excess. It is a free world.
 
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If you should be fortunate enough to have loudspeakers with flat and smooth on-axis response why would you change it by equalizing a room curve? If a room curve has an unappealing shape, it is most likely because of off-axis - i.e. directivity - problems and equalization cannot change that. The solution is a better loudspeaker
I can’t agree, I have a good (not the best but not bad) loudspeaker and equalization allows me to avoid some unexpected resonances in a satisfactory way: for example window behind my 8030 Genelec produce an irritant 400 Hz bump, I agree that the better solution is another placement or covering the window: EQ just disimules the resonance which, agree, doesn’t sound as it should be (I’m pianist and so sensitive to the distortion on this instrument, it hurts!).

But most of us we live in small places and cannot allow top of the line speakers, to me my 8030 are on my very best I can have and if equalizing improves some regions, I’m happy to make it.

I never red your book but once I have enough time I will do it. Congratulations to your work and Mr Olive’s one: I’m learning some new interesting information.
 
I can’t agree, I have a good (not the best but not bad) loudspeaker and equalization allows me to avoid some unexpected resonances in a satisfactory way: for example window behind my 8030 Genelec produce an irritant 400 Hz bump, I agree that the better solution is another placement or covering the window: EQ just disimules the resonance which, agree, doesn’t sound as it should be (I’m pianist and so sensitive to the distortion on this instrument, it hurts!).

But most of us we live in small places and cannot allow top of the line speakers, to me my 8030 are on my very best I can have and if equalizing improves some regions, I’m happy to make it.

I never red your book but once I have enough time I will do it. Congratulations to your work and Mr Olive’s one: I’m learning some new interesting information.
A 400 Hz bump is within the domain of adjacent-boundary interactions - my books deal with the topic in an entire chapter. This is at the upper part of the transition frequency range. If it was a simple reflection EQ cannot correct a non-minimum phase phenomenon.
 
A 400 Hz bump is within the domain of adjacent-boundary interactions - my books deal with the topic in an entire chapter. This is at the upper part of the transition frequency range. If it was a simple reflection EQ cannot correct a non-minimum phase phenomenon.
Thanks for the point: I supposed that was the window, but maybe another thing…

1727018678582.jpeg


1727018704132.jpeg


These are the Left and Right corrections suggested by WiiM Ultra auto EQ: it seem to be harmonic distortion since the bump repeats on multiples, at my ear the most protruding is the yellow circle
 
Thanks for the point: I supposed that was the window, but maybe another thing…

View attachment 394058

View attachment 394059

These are the Left and Right corrections suggested by WiiM Ultra auto EQ: it seem to be harmonic distortion since the bump repeats on multiples, at my ear the most protruding is the yellow circle
If harmonic distortion products were strong enough to influence room curves the sound would be unlistenable. The yellow symbols I see identify dips. Dips are very hard to hear and narrow ones like this should not be equalized if that is what you are thinking of doing.
 
If harmonic distortion products were strong enough to influence room curves the sound would be unlistenable. The yellow symbols I see identify dips. Dips are very hard to hear and narrow ones like this should not be equalized if that is what you are thinking of doing.
Its the correction, not the measurements: unfortunately WiiM doesn’t record the results.

You have to reverse what you see: they are spikes, not dips
 
OK, understood. Most 'smart' equalization cuts resonant peaks, not boosts acoustic interference dips - unless it is a broadband spectral effect. This does not look like a smart EQ - a 10 dB narrow band boost at 70 Hz looks suspicious.
 
If harmonic distortion products were strong enough to influence room curves the sound would be unlistenable. The yellow symbols I see identify dips. Dips are very hard to hear and narrow ones like this should not be equalized if that is what you are thinking of doing.

Thank you for this information (and of course all the other information you provide!)

A question, closely related to this one you've just answered: are very narrow/high-Q dips below the transition frequency similarly hard to hear, like for example the 70Hz null in the above image? Or does the logarithmic nature of our hearing make even those narrow dips easily audible when they're down in the lower frequency range?

Thanks!
 
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