Dr. Floyd Toole research nowadays?

[sarumbear]

you might wanna google how Einstein and Newton describe gravity, the Newtonian description is completely discarded.

Einstein's theory is called general relativity. It is required calculations in space, at macroscopic scale, where absolute precision is desired. Newtonian Physics continue to be used on Earth as it defines gravity as force. Even rocket scientist use it for rocket launch calculations.

Science is not easy to be understood.

 

[rdenney]

In other words, it has changed. As in, it's not the same as before.

Newton presented a physical model, which is still true (enough) at physical scales. Quantum mechanics and relativity work at a much different scale, beyond Newton's boundaries. So, Newton's "laws" were not laws, but rather a model, and that model still works at a scale relevant to physical structures. Buildings and machines are still designed around Newtonian physics, for example. The contexts where Newton's physics are not descriptive were beyond his awareness.

Rick "still uses the laws of motion, including Newton's definition of gravity, in his daily work" Denney

 

[Hipper]

Just been listening to an ordinary CD by the band Bread from a 1971 recording and was marvelling at how well the drums and percussion sounded. This is unusual as most of the studio recordings I listen too the percussion - hi-hats, cymbals particularly - don't sound as lively as they should. Yet it can be done.

My conclusion therefore is that if my set up can reproduce good recordings well then the weakest factor is the recordings. Equipment, set up techniques etc we already have and know are well capable of good sound reproduction. It is the recording to media process that we need to get consistently right. It can be done but often it isn't.

One of Toole's 'Circle of Confusion' over which we listeners have no control.

 

[Elkerton]

I have audiophile friends whom I loaned my copies of Toole's book. The first friend is a mechanical engineer who favours open baffle speakers (Spatial Audio and GR Reseach xTremes). He had my copy of the first edition for over a year and never got through it. The second friend has large Coincident speakers, a Canadian brand, with ribbon tweeters. He had my copy of the third edition and returned it having read a third. I suspect their cherished beliefs were being compromised, but I'm not sure. I explained to them that there is very little hard data on sound reproduction, and that is why I value Toole's and Olive's and everyone's research.

 

[Frgirard]

I explained to them that there is very little hard data on sound reproduction, and that is why I value Toole's and Olive's and everyone's research.

Amazon.com

 

[Jim Shaw]

I have audiophile friends whom I loaned my copies of Toole's book. The first friend is a mechanical engineer who favours open baffle speakers (Spatial Audio and GR Reseach xTremes). He had my copy of the first edition for over a year and never got through it. The second friend has large Coincident speakers, a Canadian brand, with ribbon tweeters. He had my copy of the third edition and returned it having read a third. I suspect their cherished beliefs were being compromised, but I'm not sure. I explained to them that there is very little hard data on sound reproduction, and that is why I value Toole's and Olive's and everyone's research.

Your friends have probably started Youtube channels. No wisdom is required.

 

[fpitas]

I have audiophile friends whom I loaned my copies of Toole's book. The first friend is a mechanical engineer who favours open baffle speakers (Spatial Audio and GR Reseach xTremes). He had my copy of the first edition for over a year and never got through it. The second friend has large Coincident speakers, a Canadian brand, with ribbon tweeters. He had my copy of the third edition and returned it having read a third. I suspect their cherished beliefs were being compromised, but I'm not sure. I explained to them that there is very little hard data on sound reproduction, and that is why I value Toole's and Olive's and everyone's research.

Some audiophiles really don't care about accurate reproduction. One can argue that isn't hi-fi, but that's their preference. They like special effects of various sorts. Like dumping lots of salt on everything you eat.

 

[DanielT]

Comment from I-or, a technical consultant in acoustics and audio technology. Regarding Maarten's description of Tool's work, results that appear here:

Toole:

These sounds have been reflected only once in transit and, in most domestic-sized rooms, will arrive within approximately the first twenty to thirty milliseconds (ms) after the direct sound. They are called early reflections….

… In small rooms, such as we have in our homes, echoes are almost never a problem, but early reflections are major determinants of what we hear from loudspeakers. Obviously, the strength of individual early reflections is determined by the directivity of the loudspeakers and the reflectivity of the walls. So, when measuring the loudspeaker we must do so at the appropriate angles away from the forward axis. Doing this means that we need information about typical rooms and the arrangements of loudspeakers and listeners within them….

...Sound power is a measure of all of the sound radiated from a loudspeaker in all directions.

https://www.harman.com/documents/AudioScience_0.pdf

I-or:

A very good and educational description. I just have a few small comments:

1. It is true that with simpler methods all sources are simulated as rigid pistons, which means that real elements with break ups will obtain a lower degree of directivity in the upper part of the pass band than in the simulation results. The differences between measurement data and simulation results for directivity index are around 2-3 dB, which is not bad at all, but also not enough to be directly useful.

2. The direction is of course two-dimensional rather than three-dimensional because it can be described by two angles.

3. Regarding the frequency dependence of the dispersion, I am not so sure that it is optimal to have a fairly constant rise towards higher frequencies since this property is only a side effect of how conventional speakers are designed. Some quite odd constructions that have had clearly deviating sound dispersion during Harman's listening sessions have probably carried many other weaknesses, but above all the dispersion has not been particularly suitable either.

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).

6. Finally, Olive's formula is of course "middle of the road" in all respects because Harman really only wants to sell speakers and thus is mostly interested in what listener Joe Schmoe (and possibly his wealthier brother Jonathan Schmoe Jr) will buy. This means that above all the importance of deviations in the acoustic environment and program material relative to the test set-up is not reflected in the results.

(translated directly with google translate, proofread it but I may have missed something in the translation)

Page two from this thread:

faktiskt.io • Visa tråd - 1: Frekvensgång, 2: Spridning, .. Spinorama?

Edit
Speaking of Google Translate:

To non-English speaking members - could you please stop using auto translators?

Because it makes you post and quote people in the wrong language. Without you noticing. English is still a language worth learning. So why not take the opportunity to consume and produce some of it while having fun here? And just use Google Translate on the side to help you out. In my...

audiosciencereview.com

 

[ctrl]

About 1)
The context seems to be missing. Because Toole and Olive, as far as I know, never referred to BEM simulations in their work. Their work is based on real measured data.

BEM models are usually based on ideal drivers, so the simulation results become inaccurate when the driver no longer shows piston-like behavior in reality. So this statement is true.
However, something like BEM modeling is not discussed at all in Toole's book.


About 2)
I don't know how often Toole talks about "direction" in his book, but quite often he talks about "directivity" with respect to loudspeakers. In addition to the angles, one also need the distance (since the directivity of an LS changes with distance because of the phase shift between drivers and phase shift of the secondary sound sources caused by edge diffraction).


About 3)

Regarding the frequency dependence of the dispersion, I am not so sure that it is optimal to have a fairly constant rise towards higher frequencies since this property is only a side effect of how conventional speakers are designed.

I don't recall Toole and Olive making such a specification regarding radiation patterns.

What is considered positive by Toole and Olive, however, is when sound power (SP) and predicted in-room response (PIR) slope down as evenly as possible toward high frequencies - how this is achieved is secondary.
Here, however, Sean Olive admits that it is not entirely clear exactly what this downward slope should look like (steepness of the curve), depending on the loudspeaker design.

 

[Hipper]

Even in small rooms (mine is 386 x 420 x 240 cm high) you can hear reflections, both off walls but also from other items like furniture or equipment. For example I had my Hi-Fi gear sat between but behind my stereo speakers and could hear reflections off them. I could also hear diffusors on the side walls.

With reflections, psychoacoustics comes into play, notably the Precedence Effect and that appears to vary with personal experience.

https://en.wikipedia.org/wiki/Precedence_effect

Reflections can also have another effect, discussed by Toole on page 159, in relation to 'interaural crosstalk'. To summarize, in a stereo set up, your left ear not only hears the sound from your left speaker but also some from the right speaker. This bends round your head to your ear and the extra distance travelled - 7"-8" - leads to interference of the two sounds causing comb filtering which causes a dip at around 2kHz of perhaps 6dB. Apparently this is partially made up by side wall reflections. Of course the 2kHz region is a key area for the stereo phantom image.

I've tried to control side wall reflections with room treatment and still get a strong centre image. You can also control the interaural crosstalk, either with room treatment on the inside of the speaker or using DSP - known as Ambiophonics. I keep meaning to experiment with this.

 

[DanielT]

About 1)
The context seems to be missing. Because Toole and Olive, as far as I know, never referred to BEM simulations in their work. Their work is based on real measured data.

BEM models are usually based on ideal drivers, so the simulation results become inaccurate when the driver no longer shows piston-like behavior in reality. So this statement is true.
However, something like BEM modeling is not discussed at all in Toole's book.

Hmm, strange. He is usually meticulous and well-read. Maybe something Harman did? Or it is just a general finding. It is possible that he commented from several different posts in his reply I pasted.

Because Toole and Olive, as far as I know, never referred to BEM simulations in their work. I-or must know that, but ok even a knowledgeable and experienced person can mix things up and be wrong.

But I hadn't thought of this, as he said:
Olive's formula is developed in Harman's listening room,

But having said that, it does not necessarily mean that you can generalize based on those results. But it should still mean something.

Edit:
Now I have researched, the thread is also about different simulations, plus discussion about different drivers. That was what was intended, I-or replies to various posts. It had nothing to do with Toole and Olive per se, point 1 that is. You don't need to read the thread, see the graphs on the previous and second pages and you will understand. Sorry for the confusion

faktiskt.io • Visa tråd - 1: Frekvensgång, 2: Spridning, .. Spinorama?

 

[Curvature]

Hmm, strange. He is usually meticulous and well-read. Maybe something Harman did? Or it is just a general finding. It is possible that he commented from several different posts in his reply I pasted.

Because Toole and Olive, as far as I know, never referred to BEM simulations in their work. I-or must know that, but ok even a knowledgeable and experienced person can mix things up and be wrong.

But I hadn't thought of this, as he said:
Olive's formula is developed in Harman's listening room,

But having said that, it does not necessarily mean that you can generalize based on those results. But it should still mean something.

Why don't you read Toole's book for yourself?

That person's commentary was partially informed at best.

 

[DanielT]

Why don't you read Toole's book for yourself?

That person's commentary was partially informed at best.

Yep, I have now ordered the latest version. It will be fun and interesting reading.

Tip:

 

[DanielT]

Floyd Toole's own words about the present and the future:

From this thread, #550:

omnidirectional loudspeakers = best design available

Makes me wonder what the "flagship speaker" in the graph is ? I'll keep wondering , you show professional courtesy by not name calling anything , suppose the designer of it can see the graph in your book and recognize it :) What the heck, it was a Yamaha. Not a Yamaha designed in Japan, where...

audiosciencereview.com

 

[Trell]

I have a question for you: have their been any new research on Newton’s theories since the 17th century?

Are you thinking of his research in alchemy?

Newton and Alchemy: The Chymistry of Isaac Newton Project

Isaac Newton, like Albert Einstein, is a quintessential symbol of the human intellect and its ability to decode the secrets of nature. Newton wrote and transcribed about a million words on the subject of alchemy, of which only a tiny fraction has today been published. With the support of the...

webapp1.dlib.indiana.edu

 

[Jim Shaw]

Toole's agency's studies of the preferences of human test subjects and the statistics of that are bedrock. They should be required reading and review for anyone who does subjective ratings involving test listening, yearly.

If a reviewer hasn't read and understood Toole, I would doubt their ability to accurately review a clock radio. -Just one man's view.

I long ago came across this YT video of Toole's presentation before some subsection of the AES. I rewatched it yesterday and was again assured of his profound science. Do not denigrate Toole unless you have heard him and read his latest edition book. That said, nobody ever said that Toole's work tried to cover every possible aspect of reproduced sound.