April 2015 Toole video on sound reproduction

das

Industry Expert
Nov 15, 2010
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I still don't get it. Surely if you correct what actually arrives at the listening position, you are by definition, correcting the on and off- axis reponses.

No. You can't correct what's launched from the speaker at the listening seat.

Will a speaker+room corrected at the listening position sound better (at the listening position) if the on and off -axis responses match well? If so, why? (assuming there are 'welll behaved" corrections - eg no massive suck-outs etc)

Yes, if the on- and off-axis responses match well (assuming a fairly linear speaker to begin with), then the end result will be better. This is more or less the basis for Toole's work, which began decades ago.

The reasons are too lengthy to get into here, but you can find papers, books, videos, etc., explaining why.

Doug Schneider
www.soundstage.com
 

das

Industry Expert
Nov 15, 2010
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I agree with that but the argument you make is an oversimplification which ignores how advanced DSP softwares work.

Hi,

If you can show me one software package that can correct the off-axis response of a speaker to match it's on-axis response -- actually change the response -- I'll eat my words.

Doug Schneider
www.soundstage.com
 

Whatmore

Well-Known Member
Jun 2, 2011
1,011
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438
Melbourne, Australia
No. You can't correct what's launched from the speaker at the listening seat.



Yes, if the on- and off-axis responses match well (assuming a fairly linear speaker to begin with), then the end result will be better. This is more or less the basis for Toole's work, which began decades ago.

The reasons are too lengthy to get into here, but you can find papers, books, videos, etc., explaining why.

Doug Schneider
www.soundstage.com

Apologies again if I'm not beaing clear (and also if I'm asking dumb questiions :) )
I'm not suggesting that we change the off-axis response of the speaker itself.
I'm asking why we care about it at all if we can correct the entire response that arrives at the listening chair

Perhaps you could point me in the direction of some reading/videos that might me understand better
 

amirm

Banned
Apr 2, 2010
15,813
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Seattle, WA
Contacted Dr. Toole regarding the identity of the $1,800 speaker and he was kind enough to answer the riddle. As I had speculated, it was an Infinity Interlude speaker. It did not sell well and was discontinued!!!
 

dallasjustice

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NorthStar

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Contacted Dr. Toole regarding the identity of the $1,800 speaker and he was kind enough to answer the riddle. As I had speculated, it was an Infinity Interlude speaker. It did not sell well and was discontinued!!!

Thx Amir.

Infinity Interlude IL60:

* Review Link: http://www.manualsdir.com/manuals/126626/infinity-interlude-il60.html



______

- I have in front of me the Stereophile Guide to Home Theater (January 2002 issue), on page 86 where the Infinity Prelude IL60 (Surround Speaker System) was reviewed by Michael Fremer.
The Interlude IL60 loudspeakers were retailing back then for $2,000/pair. It is indeed the speaker talked about by Floyd E. Toole in that video; "dangerously close to perfection". ...The specs are dead on, the measurements very very similar, and the bass good to 38Hz (-3dB). @ 30Hz it is minus 10dB. ...But in-room response will provide solid bass reinforcement down to 30Hz for sure.
I should note that the measurements here differ because they were not taken in the same exact conditions as the ones showed in that video.
But the on-axis response curve is a beauty, mainly flat. The off-axis curve @ 45° diverges starting @ around 4kHz, being down 6dB @ that frequency point.
@ 60° off-axis, it is 9dB down @ 4kHz, and 22.5dB down @ 15kHz.

P.S. Finally, I was able to get the link of that full review. ...But without the measurements (the one supplied above is NOT from that review).
And I tried to transfer my downloaded file, but every time I tried that (any file @ all) it simply does not work.
It seems that the "file" feature is inoperative.

P.P.S. Click on "Original Mode" @ the top and you'll get the full measurements as well.
All together there are three pages, and @ each page you'd have to click on 'Original Mode'.
Voila, everything is there: Manufacturer's Specs, List price, Full Review by Michael Fremer, Measurements by Tom Norton (on page 2 - 'Original Mode' that you have to click @ the top), and Pictures of the Speakers.
 
Last edited:

NorthStar

Member
Feb 8, 2011
24,305
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435
Vancouver Island, B.C. Canada
Thank you for your patience; it was a learning process for me, as I was trying to get everything working; links, downloads, files, pictures.
That review wasn't easily accessible, and that was a new source for me, and that I wasn't familiar with; like to get the measurements included.

And that graph that I just posted above, it wasn't easy either because the URL link was wrong @ the beginning, and it wasn't me, but my computer.
Me I simply transcribe that URL address. But it wasn't working; I had to go back and forth few times until I finally got it. ...A simple PC glitch, on this side of the border.

* TEST: I'll try again to download a simple file from my computer, a small image with low resolution.... ....No, it doesn't work, even from the smallest low-res picture. It's under the "Attachments" feature by the way.
It's no big deal, I can manage around. ...It just takes more time, same as when you want to post an image (Insert Image), a picture, a photograph, a youtube video (Insert Video). ...Amir is the expert in that kind of stuff (Microsoft man). :b

___________

 

amirm

Banned
Apr 2, 2010
15,813
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Seattle, WA
I'll ask a different way. Will a speaker+room corrected at the listening position sound better (at the listening position) if the on and off -axis responses match well? If so, why? (assuming there are 'welll behaved" corrections - eg no massive suck-outs etc)
The reasoning has to do with evolution and cognition. Take the simplest case of sending the identical sound on direct axis and the reflected one. The only difference them is in arrival time. The off-axis takes longer to get to the ear due to longer travel time. Our brain has figured out that this delayed sound is redundant. It brings no more information. In this situation, the brain after a bit of adaptation, starts to filter out the reflected sound. Again, we are talking about an ideal situation where the on and off-axis are identical.

At the other extreme, assume the two signals are wildly different. Now there is no redundancy. We hear one thing, and a few milliseconds later, hear something else. Now there is no reason to discard the second sound as it could be something other than a reflection. The reflection is now "heard."

A speaker is somewhere in these two extremes. It reasons that the closer you are to the ideal, the more you enable the brain to filter out the reflection and "hear through the room." The reflections are no longer distractions or distortions. They are redundant and filtered out after adaptation. Such a speaker therefore sounds good in many more places since the reflections are not material in general sense.
 

Phelonious Ponk

New Member
Jun 30, 2010
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So once again, the elephant is in the room -- a body of work spanning decades of testing, concluding that...

1) Smooth, linear response, on and off axis, leads to more accurate reproduction (higher fidelity, and this shouldn't be the slightest bit controversial).

2) When non-audio influencers are removed, listeners, from the trained and experienced to students, prefer more accurate reproduction.

3) That achieving that kind of reproduction is not very expensive; it has been done in speakers that the high end would barely classify as "midfi." (vinly-covered Infinitys? Please. They'd get no respect in this community without a report like this).

4) That audiophile journalists are among the worst listeners, or at least among the least capable of recognizing high fidelity when they hear it.

...the same scientist who tells us all the above also tells us that high-end cables make no difference, that achieving linear performance in electronic components is easy, and that active speakers are simply a better design that he hopes is the future of audio...

To me, it's very supportive of a number of my beliefs, particularly the one that says "high end" is defined by cost and prestige, driven by personal preference, not better performance, and that it often actually delivers lower performance than midi.

But this has got to be very challenging to the high-end hobby. Anybody putting their big rig on the market this week and launching a search for some used Infinitys? :) I'd love to see Toole and Olive test some Linkwitz speakers, by the way...

Tim
 

Phelonious Ponk

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Jun 30, 2010
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Yes agree, most of the 'high end' has absolutely nothing to do with furthering the quest for fidelity, I associate it with the luxury and vulgar, watch market , jewels encrusting a very ordinary mechanism.
Keith.

So the brands you sell, then, are simple, well-constructed, engineered with the goal of higher fidelity to the source and not inordinately expensive? Perhaps I need to be a customer.

Tim
 

amirm

Banned
Apr 2, 2010
15,813
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0
Seattle, WA
So once again, the elephant is in the room -- a body of work spanning decades of testing, concluding that...

1) Smooth, linear response, on and off axis, leads to more accurate reproduction (higher fidelity, and this shouldn't be the slightest bit controversial).

2) When non-audio influencers are removed, listeners, from the trained and experienced to students, prefer more accurate reproduction.

3) That achieving that kind of reproduction is not very expensive; it has been done in speakers that the high end would barely classify as "midfi." (vinly-covered Infinitys? Please. They'd get no respect in this community without a report like this).

4) That audiophile journalists are among the worst listeners, or at least among the least capable of recognizing high fidelity when they hear it.

...the same scientist who tells us all the above also tells us that high-end cables make no difference, that achieving linear performance in electronic components is easy, and that active speakers are simply a better design that he hopes is the future of audio...

To me, it's very supportive of a number of my beliefs, particularly the one that says "high end" is defined by cost and prestige, driven by personal preference, not better performance, and that it often actually delivers lower performance than midi.

But this has got to be very challenging to the high-end hobby. Anybody putting their big rig on the market this week and launching a search for some used Infinitys? :) I'd love to see Toole and Olive test some Linkwitz speakers, by the way...

Tim
Let me just add one important nuance here. Dr. Toole's teachings and research is what I call the "high order bit." In other words, the principals of good sound. There are secondary issues of fidelity that he doesn't normally get into because so many people miss the high order bit. As an example, one can achieve similar frequency responses with two drivers but have it have more distortions.
 

JackD201

WBF Founding Member
Apr 20, 2010
12,308
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Manila, Philippines
So once again, the elephant is in the room -- a body of work spanning decades of testing, concluding that...

1) Smooth, linear response, on and off axis, leads to more accurate reproduction (higher fidelity, and this shouldn't be the slightest bit controversial).

2) When non-audio influencers are removed, listeners, from the trained and experienced to students, prefer more accurate reproduction.

3) That achieving that kind of reproduction is not very expensive; it has been done in speakers that the high end would barely classify as "midfi." (vinly-covered Infinitys? Please. They'd get no respect in this community without a report like this).

4) That audiophile journalists are among the worst listeners, or at least among the least capable of recognizing high fidelity when they hear it.

...the same scientist who tells us all the above also tells us that high-end cables make no difference, that achieving linear performance in electronic components is easy, and that active speakers are simply a better design that he hopes is the future of audio...

To me, it's very supportive of a number of my beliefs, particularly the one that says "high end" is defined by cost and prestige, driven by personal preference, not better performance, and that it often actually delivers lower performance than midi.

But this has got to be very challenging to the high-end hobby. Anybody putting their big rig on the market this week and launching a search for some used Infinitys? :) I'd love to see Toole and Olive test some Linkwitz speakers, by the way...

Tim

Wow. Your own biases are showing Tim. It ain't pretty.
 

Phelonious Ponk

New Member
Jun 30, 2010
8,677
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Wow. Your own biases are showing Tim. It ain't pretty.

Watch the video; I just repeated what Toole said. But I'm not trying to hide my opinion. I absolutely believe what he said is true. Does that make it an ugly bias? That's interesting. What about everyone else's opinions? Prettier?

Tim
 

valkyrie

Well-Known Member
Sep 12, 2011
65
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315
Bravo TIM!!!!! Now everybody will pile on for you noticing the mastodon in the mansion.
 

Nyal Mellor

Industry Expert
Jul 14, 2010
590
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I still don't get it. Surely if you correct what actually arrives at the listening position, you are by definition, correcting the on and off- axis reponses.

I'll ask a different way. Will a speaker+room corrected at the listening position sound better (at the listening position) if the on and off -axis responses match well? If so, why? (assuming there are 'welll behaved" corrections - eg no massive suck-outs etc)

The ear combines the direct + early reflected + late reflected field into what you hear.

If you measure the response at the listening position you are looking at a frequency response that resembles the speaker off axis at the angles that cause the early reflections. So simplistically speaking if you see a 3dB dip in the response at the listening position from say 1.5-2.5kHz and then correct that what you have done is boosted the on axis 3dB as well as the off axis. Likely the response on axis was flat to begin with so now if you measure the speaker nearfield you will see a 3dB peak from 1.5-2.5kHz. At the listening position it looks great but you have made the on axis response (direct sound) worse.
 

Nyal Mellor

Industry Expert
Jul 14, 2010
590
4
330
SF Bay Area, CA, USA
Let me just add one important nuance here. Dr. Toole's teachings and research is what I call the "high order bit." In other words, the principals of good sound. There are secondary issues of fidelity that he doesn't normally get into because so many people miss the high order bit. As an example, one can achieve similar frequency responses with two drivers but have it have more distortions.

This is an EXTREMELY IMPORTANT point. I think people listen / read Toole and assume speaker directivity and frequency response are the only thing that matters.

Clearly this is not the case, and there are many other things going on with speaker design that impact the end sound quality. If you listen to the Home Theater Geeks webinar on the development of the M2 loudspeaker and you hear them talking about the bass driver design then you'll see there is more at Harman beyond just directivity.


Sure I sell ATC but the guys there have a rounded understanding of what goes into making a good speaker, see here for their "7 key parts to high performance speaker design and development"
: http://www.transaudiogroup.com/atcforums/index.php?topic=2.0. Others like KEF and Vivid also clearly have a good understanding.

Others I am not sure about, like B&W, Raidho, Wilson...clearly they have some smart people working there but they purposely design their speakers to be non-neutral.

And then there are some who do not even measure their speakers during the development process. Tyler Acoustics, for example.
 

JackD201

WBF Founding Member
Apr 20, 2010
12,308
1,425
1,820
Manila, Philippines
Watch the video; I just repeated what Toole said. But I'm not trying to hide my opinion. I absolutely believe what he said is true. Does that make it an ugly bias? That's interesting. What about everyone else's opinions? Prettier?

Tim

Of course I watched it. Your number 2 is just flat out wrong. They all preferred the same way. The variance is in the way they scored it on the scale. Watch it again. The same refers to number 4.

If you want to pigeon hole groups fine. All I'm saying is that Toole clearly qualified the variances and it appears the qualifications were ignored outright.

Also it is funny that the "circle of confusion" is being ignored. That to me is the most important point of the whole lecture.
 

Whatmore

Well-Known Member
Jun 2, 2011
1,011
2
438
Melbourne, Australia
Of course I watched it. Your number 2 is just flat out wrong. They all preferred the same way. The variance is in the way they scored it on the scale. Watch it again. The same refers to number 4.

If you want to pigeon hole groups fine. All I'm saying is that Toole clearly qualified the variances and it appears the qualifications were ignored outright.

Also it is funny that the "circle of confusion" is being ignored. That to me is the most important point of the whole lecture.

The circle of confusion was very interesting. I've always wondered why we audiophiles seem to reject "studio" type speakers as being somehow too accurate
 

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