Dr. Floyd Toole research nowadays?

[Newman]

Open question. New findings, research that complements or rejects, disprove Dr. Floyd Toole theories, or some of them.

What 'Toole theories' would you like to see progressed?

Distortion and speakers for example. From what I have seen, Dr. Floyd Toole did not talk much about that,

Well if he didn't talk about it, then he didn't have a 'theory' about it, so isn't it another topic altogether?

 

[DanielT]

What 'Toole theories' would you like to see progressed?

Well if he didn't talk about it, then he didn't have a 'theory' about it, so isn't it another topic altogether?

I do not know. This is not strange, applies to all areas. I could just as easily have said: Something new has happened on the front of beekeeping since X wrote the reference work and carried out his research 40-50 years ago? In other words, I'm just generally curious and, as I mentioned earlier in the thread, I do not question Toles's research findings.

Something new must have happened in these years, right? New research. What I do not know.

New material, but it does not really concern Toole's research per se.

MIT engineers have developed a paper-thin loudspeaker that can turn any surface into an active audio source.

This thin-film loudspeaker produces sound with minimal distortion while using a fraction of the energy required by a traditional loudspeaker. The hand-sized loudspeaker the team demonstrated, which weighs about as much as a dime, can generate high-quality sound no matter what surface the film is bonded to.

Researchers develop a paper-thin loudspeaker – MIT EECS

www.eecs.mit.edu

 

[JanesJr1]

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

Yes, it's called relativity...

 

[Mart68]

Open question. New findings, research that complements or rejects, disprove Dr. Floyd Toole theories, or some of them.

Distortion and speakers for example. From what I have seen, Dr. Floyd Toole did not talk much about that, or am I wrong? But distortion and speakers affect the sound, audibly affect that is.

You are right he does not talk much about distortion in speakers, he does give a reason for that:

'in loudspeakers it is fortunate that distortion is something that normally does not become obvious until devices are driven close to or into some limiting condition.... it is rare for distortion to be identified as a factor in the overall subjective ratings.' (3rd edition pg 98).

 

[Hipper]

You are right he does not talk much about distortion in speakers, he does give a reason for that:

'in loudspeakers it is fortunate that distortion is something that normally does not become obvious until devices are driven close to or into some limiting condition.... it is rare for distortion to be identified as a factor in the overall subjective ratings.' (3rd edition pg 98).

That sentence sums up my general view of Toole's work - 'in the overall subjective ratings'.

Many (all?) his conclusions come from surveys of listeners (often very experienced it must be said) and are based on the most popular views. I think it's accepted that not everyone hears the same when listening, because of our history and ear/brain condition. In other words, if you don't hear the good sound that you should according to Toole it's not necessarily that you have got things wrong. It could simply be that you hear differently. His book is not a bible, just a good informative guide which you can stray from or ignore if it suits you.

People like me who have gone to more trouble then most (many bass traps, EQ, positioning in a dedicated room) to get something that sounds good may not meet the approval of Toole, or anyone else for that matter, but as long as I'm happy with my listening experience, what does it matter.

I'm not denigrating his work. I have the third edition and it has been very enlightening. I recommend it.

For this reason I find it hard to believe there will be much more that comes to light except in specialist research areas, like room treatment, DSP and of course speaker construction.

 

[Tangband]

There is some things that Toole dont mention a lot, one is the benefit of low distortion in loudspeakers, the other is the benefit of a thick rug infront of the loudspeakers.
In recording context, there is common knowlegde that one should avoid to have early reflections ( 2-5 ms ) from the mic to the recorded instruments, this is why the mics always are put at a certain distance from the floor, often above the instrument player.

The same applies to 2 channel listening in your listeningroom - one should avoid the floor bounce and very near side-walls within 2-5 ms delayed reflection. If not - the sound will be less clear. This is why its important with a loudspeakerstand. 1 ms is 34,3 cm in room temperature so you can do the counting.

 

[Elkerton]

From what I understand, since Dr. Toole retired, the research he initiated has been continued by Dr. Sean Olive et al at Harman, though most of it is now centred on headphones, the most useful research on loudspeakers already completed. Unfortunately, the folks at Harman have decided to keep the results of all further research to themselves, or at least, most of it. They have graciously made what came before available to the world, which is a big deal because building the facilities and testing products within them is very, for most, prohibitively expensive. The rest of the industry would be poorer without it, and will be, not getting the results of any new research, some of which may show up in the annals of the AES (Audio Engineering Society). We can hope.

 

[Frgirard]

Distortion is not a problem. Rock and its subfields are full of distortions and have taken over the music business and rthe sound planet.

Atc make is marketing with the lack of distortion.

DUAL SUSPENSION TWEETER​

ATC's approach to tweeter design is unique in the marketplace. By incorporating a secondary suspension component the moving assembly is naturally constrained to travel only in the axial direction. The result is a design that suppresses rocking modes and ensures lower distortion levels


The standard SH25-76 and its ultimate 'S' spec stablemate approach these engineering challenges in different but equally successful ways. The standard tweeter has a novel and lighter moving mass bracing component, while the 'S' spec driver has an exceptionally powerful motor assembly that, when combined with the optimally stiff and lightweight coil former, delivers vanishing low levels of odd harmonic distortion and a well controlled extended frequency response beyond the limit of human hearing.

Technology | ATC Loudspeakers

atc.audio

 

[Mart68]

That sentence sums up my general view of Toole's work - 'in the overall subjective ratings'.

Many (all?) his conclusions come from surveys of listeners (often very experienced it must be said) and are based on the most popular views. I think it's accepted that not everyone hears the same when listening, because of our history and ear/brain condition. In other words, if you don't hear the good sound that you should according to Toole it's not necessarily that you have got things wrong. It could simply be that you hear differently. His book is not a bible, just a good informative guide which you can stray from or ignore if it suits you.

I lack the specific education to critique Toole, I just quoted what he says to add some context to the subject under discussion.

Nothing is a bible, except for The Bible.

 

[tifune]

I know the design team has strong focus on distortion reduction in speakers.

Are you able/willing to elaborate on that at all? I can think of at least one other well-known evidence based reviewer, as well as some references above, who seems unconvinced reasonable levels of distortion play much role in a speakers "likeability" (for lack of a better term). Unfortunately he's not around to define 'reasonable' so I'm doing my best to represent him based on his post/review history; hopefully I'm in the ballpark...

Point being, given available evidence I'm wondering what pushed JBL in that direction. Is it as simple as bring 7-series distortion metrics to the 3-series, or something more interesting?

 

[Newman]

That sentence sums up my general view of Toole's work - 'in the overall subjective ratings'.

Many (all?) his conclusions come from surveys of listeners (often very experienced it must be said) and are based on the most popular views. I think it's accepted that not everyone hears the same when listening, because of our history and ear/brain condition. In other words, if you don't hear the good sound that you should according to Toole it's not necessarily that you have got things wrong. It could simply be that you hear differently.

I don’t know how many times people keep saying this, and it needs correction every time.

One of Toole’s most important findings is that human preferences for reproduced sound quality don’t vary much at all. We are all very similar. It’s not a wide bell curve, it is a very narrow one. So when he says “in the overall subjective ratings” it probably applies to the vast majority of listeners.

“If you don’t hear the good sound that you should”, it is not because people’s preferences are all unique and evidence that we are all different; it is because “you” are doing sighted listening and non-sonic factors are dominating your impressions. Do it blind and “you” will probably fall into line and agree with the findings.

cheers

 

[GXAlan]

What 'Toole theories' would you like to see progressed?

I think the Sony HT-A9 is a really interesting concept for multichannel audio. You have wireless speakers which themselves have microphones. So instead of moving mic analysis, you have speakers that can play a test tone and have four points of measurement (self and three others) so there is knowledge of room acoustics and relationships.

Sony uses this with low end speaker drivers and an iffy wireless protocol to give you really impressive sound bar like quality. Now imagine if you applied this technology with Dirac-like PC based calculations that can be applied in integrated amps or receivers. You not only have your listening position measurements, but have triangulated Trinnov-style understanding. Trinnov does speaker remapping which is not favored by the JBL Synthesis SDP-75 but is more a reflection of “algorithms need work” as opposed to something that doesn’t make sense. If Trinnov’s remapping algorithms aren’t good enough, maybe comparing them to Sony would help a new “arms race” or better virtualization as we saw from Pro-Logic to present day.

Sonos does a trick with its sound bars to increase bass. If you know that lower frequencies are hard to localize, why not play low frequency effects on other speakers?

If I have a taiko drum in a 2 ch recording and I am listening to it on my home theater in two channel (not surround upmixed), if I had full range rear speakers, what would happen if 60Hz and below was being played from the rear speakers too? In theory, 80Hz and below is not localized?

Now we run into issues of phase interactions and cancellation effects and this might be where the ability to have multichannel mic recordings that essentially represent the bounding box of the sound volume come into play.

 

[DanielT]

But come on now. Distortion in speakers can definitely be, or become audible. For example :

GR Research LGK 2.0 Speaker Review (A Joke)

This is a review and detailed measurements of the GR Research "Little Giant Killer" (LGK) 2.0 bookshelf speaker. It comes in various forms from a kit ($313) to fully finished pair ($1,038). Our DIY expert @Rick Sykora built my sample using the flatpack ($100): Rick had to do the round over on...

audiosciencereview.com

Or take a clock radio, speakers on the TV. Turn up the volume really high and it sounds crap. Everyone can hear this, even those who do not into HiFi.
(It may be the small amplifier that in these cases that is driven into clipping.Which is the reason for the lousy sound, I should add)

Sensible HiFi speakers that have decent power, can handle decent power, then it will be trickier to hear, compared to the examples above.

By the way. Speakers can have straight FR with high, relatively high, distortion and vice versa. Uneven FR but low distortion.

I think that what matters, on a descending scale, begins with the most important thing:
FR
Directivity, dispersion
Distortion

Besides, aren't there slightly different opinions about this with first reflexes? How much you should dampen them. Though it might be a matter of taste?

Edit:
By the way, if you do not need to worry about distortion in speakers, why do so many people care about SINAD here at ASR when it comes to amplifiers and especially DACs? The little they add to the sound chain compared to the speakers is in this context then more or less negligible.

 

[JanesJr1]

But come on now. Distortion in speakers can definitely be, or become audible. For example :

GR Research LGK 2.0 Speaker Review (A Joke)

This is a review and detailed measurements of the GR Research "Little Giant Killer" (LGK) 2.0 bookshelf speaker. It comes in various forms from a kit ($313) to fully finished pair ($1,038). Our DIY expert @Rick Sykora built my sample using the flatpack ($100): Rick had to do the round over on...

audiosciencereview.com

Or take a clock radio, speakers on the TV. Turn up the volume really high and it sounds crap. Everyone can hear this, even those who do not into HiFi.
(It may be the small amplifier that in these cases that is driven into clipping.Which is the reason for the lousy sound, I should add)

Sensible HiFi speakers that have decent power, can handle decent power, then it will be trickier to hear, compared to the examples above.

By the way. Speakers can have straight FR with high, relatively high, distortion and vice versa. Uneven FR but low distortion.

I think that what matters, on a descending scale, begins with the most important thing:
FR
Directivity, dispersion
Distortion

Besides, aren't there slightly different opinions about this with first reflexes? How much you should dampen them. Though it might be a matter of taste?

Edit:
By the way, if you do not need to worry about distortion in speakers, why do so many people care about SINAD here at ASR when it comes to amplifiers and especially DACs? The little they add to the sound chain compared to the speakers is in this context then more or less negligible.Compare that to what the speakers add in the form of distortion.

I also have a strong perception that distortion, especially in the bass frequencies, is a strong factor in my appreciation of headphones. I know the discussion above focuses on loudspeakers, but I don't want to encourage a conventional wisdom that distortion doesn't matter in some cases.

Help me if I'm mistaking the situation, but when I listen to my HD6XX headphones, which have relatively high bass distortion that probably increases when they are EQ'd to push their low-bass droop closer to the Harman curve, I hear a not entirely unattractive, but ultimately congested low end. When I EQ them, I have to battle a low-mid bloom and I get the feeling of much detail lost or masked with familiar material. When I switch to my low-distortion, bass-rich, closed-back DCA planars, the sound of the low-end is fantastic by comparison, and they are much easier to EQ.

When all I had was the HD6XX, I mostly liked them, and Amir and others have said of them, that it's better to boost their bass than not because the ear perceives the harmonic distortion as part of the fundamental. With low-distortion phones to compare to, I am instead sensitized to the sound of low-distortion bass and profoundly prefer it. When I switch back to the HD6XX I still appreciate the nice midrange and the treble as I have EQ'd it; but I can't listen to them for long because of the lower end. Am I missing something? Doesn't distortion still matter?

 

[Kal Rubinson]

I think the Sony HT-A9 is a really interesting concept for multichannel audio. You have wireless speakers which themselves have microphones. So instead of moving mic analysis, you have speakers that can play a test tone and have four points of measurement (self and three others) so there is knowledge of room acoustics and relationships.

If there isn't an additional microphone at the listening position, the system is flawed.

 

[Curvature]

There is some things that Toole dont mention a lot, one is the benefit of low distortion in loudspeakers, the other is the benefit of a thick rug infront of the loudspeakers.
In recording context, there is common knowlegde that one should avoid to have early reflections ( 2-5 ms ) from the mic to the recorded instruments, this is why the mics always are put at a certain distance from the floor, often above the instrument player.

The same applies to 2 channel listening in your listeningroom - one should avoid the floor bounce and very near side-walls within 2-5 ms delayed reflection. If not - the sound will be less clear. This is why its important with a loudspeakerstand. 1 ms is 34,3 cm in room temperature so you can do the counting.

I can tell you did not read his papers or book. Shameful.

 

[Tangband]

I can tell you did not read his papers or book.

Yes I did - four times.

 

[GXAlan]

If there isn't an additional microphone at the listening position, the system is flawed.

Agreed, which is where a premium “audiophile” option of this underlying technology may be valuable instead of a home theater in a box design that is heavily flawed/compromised to provide the easiest “non technical” install. I think the Sonos concept of using every full range speaker in your setup to augment bass is interesting given the power of today’s computers.

The Sony actually has a pair of microphones in each speakers, so 8 (!) and then you can use the remote control to move the sweet spot. I agree it’s silly that they don’t offer a microphone at the listening position to provide an initial setting for the sweet spot location.

I do think that there is also need for enhancing the listening experience across a wider seating arrangement. The JBL Everest DD55000, S2600, S3100, and 4460 sacrificed single-seat “A+ listening position” to a wider range of A- listening positions across a few seats left to right.

 

[DanielT]

Agreed, which is where a premium “audiophile” option of this underlying technology may be valuable instead of a home theater in a box design that is heavily flawed/compromised to provide the easiest “non technical” install. I think the Sonos concept of using every full range speaker in your setup to augment bass is interesting given the power of today’s computers.

The Sony actually has a pair of microphones in each speakers, so 8 (!) and then you can use the remote control to move the sweet spot. I agree it’s silly that they don’t offer a microphone at the listening position to provide an initial setting for the sweet spot location.

I do think that there is also need for enhancing the listening experience across a wider seating arrangement. The JBL Everest DD55000, S2600, S3100, and 4460 sacrificed single-seat “A+ listening position” to a wider range of A- listening positions across a few seats left to right.

Speaking of Sonus. Seems actually quite ok. Not so expensive either:

Objective measurements don't fully support my highest honors but my listening test results do. So it is my pleasure to give a strong recommend to Ikea SYMFONISK picture frame speaker by Sonos.

Ikea SYMFONISK Picture Frame Speaker Review

This is a review and detailed measurements of the Ikea SYMFONISK picture frame speaker designed by Sonos. I purchased it a couple of days ago from Ikea store for US $199. Their website said they had 42 in stock so they are planning to sell a lot of them. That said, there was not a single...

audiosciencereview.com

 

[GXAlan]

Speaking of Sonus. Seems actually quite ok. Not so expensive either:

Objective measurements don't fully support my highest honors but my listening test results do. So it is my pleasure to give a strong recommend to Ikea SYMFONISK picture frame speaker by Sonos.

Ikea SYMFONISK Picture Frame Speaker Review

This is a review and detailed measurements of the Ikea SYMFONISK picture frame speaker designed by Sonos. I purchased it a couple of days ago from Ikea store for US $199. Their website said they had 42 in stock so they are planning to sell a lot of them. That said, there was not a single...

audiosciencereview.com

I went from a Devialet Phantom Silver stereo pair to Sonos Fives with the Gen3 sub. I also have the Sonos Arc and Gen3 sub/rears in a bedroom. Also have a Sonos Roam and an IKEA Gen 2 Sonos table lamp.

They punch well above their price point and given how expensive the Devialet’s were, I was able to really achieve multiroom support that was reliable and didn’t randomly jump to 100% volume without too much pain to the wallet.

We talk about the Klippel NFS being a game changer but Sonos has some of the largest anechoic chambers in the world and economies of scale that really translate into a lot of value. Their software is excellent with a few silly nagging issues which they don’t seem to care about for local network playback.

That said, even though many Sonos products measure well

Sonos Roam Portable Speaker: Spinorama and measurements (more proof mainstream speakers can be real good)

Measured the Sonos Roam today, the company's new, smaller bluetooth speaker. Here's the spin at 80% volume (measured at ~ 0.6m). So this is around 76dB@1m. Please read the disclaimer at the end of the post And here an estimate of it at 60% volume (i spliced a nearfield woofer measurement...

www.audiosciencereview.com

There is no question that the soundstage in my real home theater is vastly better and that music on the Arc is not as good as my JBL XPL90 at regular listening levels. I really wonder if distortion is playing a role or if stereo playback is boosting the other speakers much higher.

The Fives are great because you can run them vertically or horizontally based upon your desired sound signature preference. Pleasant sound horizontally but your phantom center is absent. Vertically, I do think it competes nicely with classics like the Revel M16 and KEF LS50. The real benefit of Sonos remains ergonomics like simple abilities to adjust volume and playback without having to go into an app.