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

[Dialectic]

As did the first-generation Revel Studio.

I always appreciated the odd looks of those speakers.

 

[OWC]

What's mostly missing in the spinorama measurements, is some more information about any additional issues and resonances.
So like a near-field burst decay (waterfall shown in periods), normal nearfield freq resp, as well as impedance.
Also done in near-field with ports and such.
I would even call this some major parameters that are totally neglected.

As in the bigger sense of the question, which has been already mentioned.
It most certainly doesn't tell us anything at all about the room a certain product is being used for.
High reverberant rooms need a completely different approach than rooms that are ideally dampened and have a (relative) constant RT60 .

It's only very limited in the focus to assume that listeners have the most perfect room setup for room reproduction.
As well as a very average and neutral taste in not only sound quality but also musical taste.

Not to mention other use cases all together.

 

[Axo1989]

You think? We'd need data. A minor point, as I said, but I predict results would show mostly absorption for soft irregular surfaces, and diffusion for hard irregular surfaces - certainly nothing approaching "pretty high" reflectivity in the articulation range. Perhaps that's why we evolved such sensitivity there - why else would we? Ascribing the anomaly to "evolution" strikes me as lazy handwaving.

My previous listening room had mini-orb side walls and custom orb back wall (small and normal profile corrugated iron respectively). That was before I indulged in measurements at home but I retrospectively wondered if there were sonic benefits (or perhaps otherwise).

My current listening room floor is traditional Japanese: tatami (woven reeds on 5 cm thick rice straw) over irregular wooden slats (with nrrow gaps). I expect behaviour somewhat different to a regular suspended t&g timber floor (more wideband absorption combined with less bass reflection). The raked ceiIing is similar timber slats (and gaps) backed by rockwool and custom orb.

I tried approximating these surfaces in terms of acoustic behaviour via the usual models (as perforated absorbers, etc). Not super accurate (and generally denser than normal ideal absorption) but because the areas are substantial I expect they contribute significantly to the fairly dry and very smooth RT60 (≤ 200 ms > 100 Hz is more mixing room that mastering room). All entirely serendipitous as there was no conscious effort to design the acoustics, but traditional Japanese architecture has fairly different (and fairly pleasant) acoustics compared to western (especially concrete but even conventional hard surface timber construction).

We've seen discussion here of US vs European (or UK) rooms (mainly the difference in average room size) but I wonder if there is anything on Japanese HiFi gear in traditional Japanese rooms?

 

[dlaloum]

My previous listening room had mini-orb side walls and custom orb back wall (small and normal profile corrugated iron respectively). That was before I indulged in measurements at home but I retrospectively wondered if there were sonic benefits (or perhaps otherwise).

My current listening room floor is traditional Japanese: tatami (woven reeds on 5 cm thick rice straw) over irregular wooden slats (with nrrow gaps). I expect behaviour somewhat different to a regular suspended t&g timber floor (more wideband absorption combined with less bass reflection). The raked ceiIing is similar timber slats (and gaps) backed by rockwool and custom orb.

I tried approximating these surfaces in terms of acoustic behaviour via the usual models (as perforated absorbers, etc). Not super accurate (and generally denser than normal ideal absorption) but because the areas are substantial I expect they contribute significantly to the fairly dry and very smooth RT60 (≤ 200 ms > 100 Hz is more mixing room that mastering room). All entirely serendipitous as there was no conscious effort to design the acoustics, but traditional Japanese architecture has fairly different (and fairly pleasant) acoustics compared to western (especially concrete but even conventional hard surface timber construction).

We've seen discussion here of US vs European (or UK) rooms (mainly the difference in average room size) but I wonder if there is anything on Japanese HiFi gear in traditional Japanese rooms?

There is definitely differences in speaker behaviour with different building construction and room sizes....

This can lead to different designs and tastes (in the anglo-sphere, the difference between USA and UK is an obvious one).

It would be interesting to do an analysis of those different construction trends and the optimal speaker types for each of them!

 

[RCAguy]

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?

View attachment 227707
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

https://www.researchgate.net/publication/332210798_A_Statistical_Model_that_Predicts_Listeners%27_Preference_Ratings_of_Around-Ear_and_On-Ear_Headphones

Why no follow up studies to Dr. Toole’s and Dr. Olive’s work?

I really enjoy objective loudspeaker measurements, but correlating measurements to what is actually perceived as optimal or perfect, if there is such a thing, is of most importance. After listening to Erin and Dr Olive’s talk about the research Dr Olive and Dr Toole did regarding the preference...

www.audiosciencereview.com

Spinorama profiles of many loudspeakers are at AudioScienceReview and Erin’s Audio Corner. Their results jibe with several Harman products, for example with mission-critical monitors.

 

[RCAguy]

“Harman’s spinorama” as implemented by Klipple and used in comprehensive reviews by both Erin at Erin’s Audio Corner and Amir at Audio Science Review. These are about the most trustworthy data analysts I’ve found. No make or model appears favored after applying good science. Erin’s videos are especially helpful and unbiased

 

[Gorgonzola]

I've stumbled on this thread for the first time, and I haven't read every post by any means. My general, layman's comments may echo other folks.

I enjoyed my dipole Magneplanar speakers for 15+ years. I don't thing that either Toole & Olive or Spinorama have adequately dealt with this category, of dipolar, bipolar, or omni-directional speakers in a way that gives any insight to their popularity, or what overall comprised a good speaker in this category.

I suspect that distortion is a much bigger factor in performance that Toole & Olive's studies have accounted for. Speaker FR can be easily corrected by modern methods, but distortion cannot. Distortion, I suspect, is a big factor in perceived detail, transparency, "air", etc.

 

[krabapple]

I've stumbled on this thread for the first time, and I haven't read every post by any means. My general, layman's comments may echo other folks.

I enjoyed my dipole Magneplanar speakers for 15+ years. I don't thing that either Toole & Olive or Spinorama have adequately dealt with this category, of dipolar, bipolar, or omni-directional speakers in a way that gives any insight to their popularity, or what overall comprised a good speaker in this category.

I suspect that distortion is a much bigger factor in performance that Toole & Olive's studies have accounted for. Speaker FR can be easily corrected by modern methods, but distortion cannot. Distortion, I suspect, is a big factor in perceived detail, transparency, "air", etc.

...and around and around we go....everything old is new again

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

1. I presume the Atmos channels can be up-mixed from conventional two-channel stereo... how well does that work, in your opinion? I have not heard enough with sufficient information about source and process to generalize. What I have heard from what I presume to be stereo upmixes have not...

www.audiosciencereview.com

 

[GXAlan]

I don't thing that either Toole & Olive or Spinorama have adequately dealt with this category, of dipolar, bipolar, or omni-directional speakers in a way that gives any insight to their popularity, or what overall comprised a good speaker in this category.

This is an acknowledged weakness of the model, but the criticism comparison is that the effect of non standard radiation patterns is “unpredictable” and the studios in which music is mixed and mastered are rarely incorporating atypical radiation patterns. It’s also important to recognize the standard deviation of the score (which is seen in the patents) and the fact that the score has helped Harman produce speakers that are bought by consumers.

That said, I completely agree with you and Dr. Toole. For direct radiating speakers, I find the spinorama to be very helpful in tiering speakers. My reference direct radiating speaker are the Meyer Sound Amie’s which have been characterized here and have slightly atypical dispersion with a shelf effect.

The other speaker that has survived the test of time are my Magnepan MG-III’s. They remain incredibly enjoyable unless you need music with specific dynamics and are consistently bringing a smile to my face.

The MG3 and Amie sound different but both are enjoyable. I know the Amie will be closer to what the music engineers at Skywalker Sound intended, but it doesn’t stop me from *enjoying* the results from the Magnepan.

I suspect that distortion is a much bigger factor in performance that Toole & Olive's studies have accounted for. Speaker FR can be easily corrected by modern methods, but distortion cannot. Distortion, I suspect, is a big factor in perceived detail, transparency, "air", etc.

It may also not be simple THD but also IMD. You can find a wide range of speakers with a flat FR, but playing something like “Another Day of Sun” from the La La Land Soundtrack or “Echo Game” from the House of Flying Daggers sound track really separates the premium from the mediocre.

The composer behind La La Land is known to use JBL Studio Monitors (7 series and 3 series currently) and the House of Flying Daggers was done at FLAIR on a Genelec setup so you know the music was mixed on a premium tier setup.

I agree though. FR is critical, and you would rather have better FR at the expense of distortion, but given two products with similar FR, there will be times that lower distortion might explain why one speaker sounds more appealing.

The other question, is that while phase error is not a big deal in mono or stereo, as you get into HT setups with 11 or 16 channels, I think phase does matter.

 

[Blockader]

What's mostly missing in the spinorama measurements, is some more information about any additional issues and resonances.
So like a near-field burst decay (waterfall shown in periods), normal nearfield freq resp, as well as impedance.
Also done in near-field with ports and such.
I would even call this some major parameters that are totally neglected.

As in the bigger sense of the question, which has been already mentioned.
It most certainly doesn't tell us anything at all about the room a certain product is being used for.
High reverberant rooms need a completely different approach than rooms that are ideally dampened and have a (relative) constant RT60 .

It's only very limited in the focus to assume that listeners have the most perfect room setup for room reproduction.
As well as a very average and neutral taste in not only sound quality but also musical taste.

Not to mention other use cases all together.

If you see a peak that repeats its pattern(doesn't have to be exactly same) in directivity index and off-axis response(s), it is a resonance. Toole talks about it in his youtube video where he talks about the highlights of his book.

 

[Anton D]

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.

Perfectly said.

As a fan of planar open baffle speakers, I am fine playing it by ear.