Floyd Toole: Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms (AES Presents) 3rd Edition - Discussion Thread

[Kal Rubinson]

Yeah... like maybe the JBL M2 speakers he helped design.

Was he involved in that?

 

[Sonnie Parker]

Was he involved in that?

Assuming Audiophile Nirvana is correct in their statement:

The M2 is the result of the acoustic research conducted by Drs. Floyd Toole and Sean Olive at JBL labs in Northridge, CA.

Perhaps he did not directly help design it, but helped influence the design.

 

[Sonnie Parker]

I found the Dirac docs interesting... http://diracdocs.com/ISEAT15_Brannmark_Sternad.pdf

My personal opinion is that Dirac Live and Mitch with Accouate Sound approach EQ filtering differently that what has been tested thus far, and until I see studies/tests by Toole or other credible authorities on the subject that include their approach to full EQ, I won't discount it. I don't think Toole really discounts it, he simply says that when they EQ above 500Hz, they may be doing more than is needed. That's a "may" because he has no evidence that their particular approach is doing more than needed because he has not tested it yet. I still suggest try both... EQ up the 500-600Hz and then full EQ, compare the two over a month or so of listening and determine what you like best.

 

[AJ Soundfield]

Thanks. Doesn’t seem like they replicated the study then (based on who the test subjects were since most of the studies that Toole mentions have both professionals and lay people)

Correct, they specifically tested studiophiles because they were the ones who went ballistic over Toole's heresy findings/publication of others findings. Remember they "know" from "decades of experience" (sound familiar to audiophiles?) that "treatments" are an elixir and the reason why Toole et als studies were flawed is that they used too many non studiophiles and/or were "Tooles" personal preference/opinion.
Not because controlled, double blind "trust your ears" tests were used, unlike with everything they believe/promote. You new to this?
Anyway, if you read audio forums, you know it's a long lost cause to Enticing Marketing Stories of all varieties.

cheers

 

[AJ Soundfield]

So below 500Hz... mic does okay at 3m?

The (omni/pressure) mic is ok at any spatial position, if you understand what it does and does not tell you.

 

[AJ Soundfield]

My personal opinion is that Dirac Live and Mitch with Accouate Sound approach EQ filtering differently that what has been tested thus far, and until I see studies/tests by Toole or other credible authorities on the subject that include their approach to full EQ, I won't discount it.

First, basic rule of logic, the onus is always, 100% on those making the claim (and $), no one else.
Second and this may be impossible for forumites to understand, the jury has long decided what "EQ" is best TO EARS in a very wide variety of rooms and in particular, the "average" (especially US) domestic living space that isn't a 6x6 tiled closet or 100 x 300x 40H auditorium. A room with "furniture", "decor" and other such radical "living room" concepts. That "curve" is actually, > 500hz 1m, as near flat as possible on axis (like your amp, dac, etc) and then as smooth at possible off axis, though not necessarily as smooth, but free of "peaks".
There is no, nor likely to be, any "magic" non linear curve, smiley face or otherwise, that ears will prefer, since that is not what ears preferred in all linear vs non-linear valid tests.
Now of course, with sighted, anecdotal "experiences" by those who believe enticing marketing stories, anything goes. Including smiley faces.
YMMV

cheers

 

[Sonnie Parker]

The (omni/pressure) mic is ok at any spatial position, if you understand what it does and does not tell you.

I'm not familiar with those terms or mics... what make/model/cylinder/horsepower are they... and the mpg?

 

[Sonnie Parker]

First, basic rule of logic, the onus is always, 100% on those making the claim (and $), no one else.
Second and this may be impossible for forumites to understand, the jury has long decided what "EQ" is best TO EARS in a very wide variety of rooms and in particular, the "average" (especially US) domestic living space that isn't a 6x6 tiled closet or 100 x 300x 40H auditorium. A room with "furniture", "decor" and other such radical "living room" concepts. That "curve" is actually, > 500hz 1m, as near flat as possible on axis (like your amp, dac, etc) and then as smooth at possible off axis, though not necessarily as smooth, but free of "peaks".
There is no, nor likely to be, any "magic" non linear curve, smiley face or otherwise, that ears will prefer, since that is not what ears preferred in all linear vs non-linear valid tests.
Now of course, with sighted, anecdotal "experiences" by those who believe enticing marketing stories, anything goes. Including smiley faces.
YMMV

cheers

Agree... but at this point with what appears to be improved methodology in the latest EQ filtering methods, there are claims on both sides, and neither side has proven anything with blind testing based on what is supposedly the latest technology and methods. I'm not ready to discount it until it's been tested that it doesn't work. Until it is tested professionally I will let my ears tell me what I like best, not based on what I see, but based on what I hear without seeing it first. And this is what several who apparently preferred no filtering above 500Hz (or have never used such filtering) have done... they received various files from Mitch and preferred the full EQ filtering. There may be some who have preferred <500Hz only, but not many thus far according to Mitch (1%). Some of these people are not looking at the results measurements, they send in the pre-EQ measurements from Audiolense or Accourate software and receive several files back to listen... plug them in convolution (or whatever system they use) and listen, with never any intentions of measuring the response, and then choose what they like best. They let their ears tell them what is best. There is nothing out there that can prove this is flawed.

 

[AJ Soundfield]

I'm not familiar with those terms or mics... what make/model/cylinder/horsepower are they... and the mpg?

Umik, etc pressure/omni.
There are other types for measuring a soundfield (no pun intended). For loudspeaker measurements, Umik et al are fine.
You really ought to continue reading the thread title to understand what an omni/pressure mic at 3-4m in room doesn't tell. It's all in there.

 

[AJ Soundfield]

Agree... but

Clearly NOT! lol

at this point with what appears to be improved methodology in the latest EQ filtering methods, there are claims on both sides, and neither side has proven anything with blind testing based on what is supposedly the latest technology and methods. I'm not ready to discount it until it's been tested that it doesn't work.

Improved according to whom? The "latest" story tellers? That's terribly circular logic. One "side" has all the evidence, the other has zero. "Anecdote" is not evidence.

Until it is tested professionally I will let my ears tell me what I like best, not based on what I see, but based on what I hear without seeing it first. And this is what several who apparently preferred no filtering above 500Hz (or have never used such filtering) have done... they received various files from Mitch and preferred the full EQ filtering. There may be some who have preferred <500Hz only, but not many thus far according to Mitch (1%). Some of these people are not looking at the results measurements, they send in the pre-EQ measurements from Audiolense or Accourate software and receive several files back to listen... plug them in convolution (or whatever system they use) and listen, with never any intentions of measuring the response, and then choose what they like best. They let their ears tell them what is best. There is nothing out there that can prove this is flawed.

Keep reading the book and real blind testing will be explained, it's nothing remotely like you just posited.
Btw, if its all about what you/your taste/preferences like best with full knowledge, sighted, etc., why not just tweak away at the EQ until you're happy? It's clear from the video that Mitch expects customers to do a purely subjective post tweak fest atop the magic curve(s).
How is he going to know what you like better than you?? Plus a purely subjective self administered EQ tweak fest is free.
Is the guise/cover of "sciency" sounding magic EQ a requirement there?

cheers

 

[AJ Soundfield]

Out of curiosity, have you ever contacted ML to see if they have anechoic data for yours?

 

[Kal Rubinson]

Assuming Audiophile Nirvana is correct in their statement:


Perhaps he did not directly help design it, but helped influence the design.

OK but so did the work of predecessors who never worked at Harman.

 

[Sonnie Parker]

Clearly NOT! lol

I agree to the extent of the test that were performed on other methods and some of the other statements you made.

Improved according to whom? The "latest" story tellers? That's terribly circular logic. One "side" has all the evidence, the other has zero. "Anecdote" is not evidence.

Have you proven they are story tellers? Have you read their docs? Have you tested what they do? The one side you reference that has evidence is not for these new filtering methodologies... as they have not tested them. They have more evidence that it works with their user's preferences than anyone else. And... Mitch does do his work manually, not automatic.

Keep reading the book and real blind testing will be explained, it's nothing remotely like you just posited.

I understand it's not like I'm doing it, but like I'm doing it is at least blind to me. Just because it's not official by the audio gods does not make it useless. It's the best I got until someone does test it.

Btw, if its all about what you/your taste/preferences like best with full knowledge, sighted, etc., why not just tweak away at the EQ until you're happy? It's clear from the video that Mitch expects customers to do a purely subjective post tweak fest atop the magic curve(s).

Again... it's not all sighted, not everyone is seeing what he has done prior to listening... and not all go in believing >500Hz will be good.

Out of curiosity, have you ever contacted ML to see if they have anechoic data for yours?

Yes I did... they stated that it's not available for consumer viewing... whatever that means. Apparently they don't want consumers to see it. I'm going to try to see what I can come up with measuring 40" at center panel and 30 degrees off-axis, but I'm not terribly hopeful in my room. I think if I could get a pair of neutral speakers with anechoic measurements and measure those in my room, it might give me some sort of baseline to compare.

Here is what Stereophile measured with their quasi-anechoic method...

The woofer is measured with the ARC correction in place... and...

The midrange is balanced slightly higher than the treble, but the rise in output between 200 and 300Hz is an artifact of the nearfield measurement technique.

 

[natty]

Classic dipole where it begins to drop off precipitously at wide angles especially at the higher frequencies.

Can sound very good but isn't the ideal that much of the research cited in Toole's book calls "usually best".

I'm sure my old Maggies had a similar dispersion....and I loved them (though I would freely admit they probably weren't what I would want to use for mastering audio, even if, allegedly, it is the kind of speaker Cat Steven's engineers used on his classic albums).

 

[AJ Soundfield]

Have you proven they are story tellers?
Have you read their docs?
Have you tested what they do?

Burden of proof
The AES ones yes and some Directions. All, no.
Burden of proof

The one side you reference that has evidence is not for these new filtering methodologies... as they have not tested them.

There is nothing "new" about claims. Nor new about folks believing said claims in lieu of a shred of evidence, while completely disregarding all evidence to the contrary, such as ears preferring neutral, which cannot be "corrected" to anything other than non-neutral, etc, etc.
And yes I'm aware of the claims about "fixing" "timing" of the onset signal magically from the contaminated, blind in room response. Also, in lieu of a shred of supporting evidence.

They have more evidence that it works with their user's preferences than anyone else.

So do the internet switch, cable lifter, power regenerator, etc. guys.

I understand it's not like I'm doing it, but like I'm doing it is at least blind to me. Just because it's not official by the audio gods does not make it useless. It's the best I got until someone does test it.
Again... it's not all sighted, not everyone is seeing what he has done prior to listening... and not all go in believing >500Hz will be good.

From the moment $500 leaves your wallet, there is no scientific validity of the "test" other than anecdote. "Blind" doesn't mean "cant see". It involves knowledge of, expectations, etc. Oh, BTW, levels matter too.
But I have no doubt you'll have some listening fun, especially with the subjective post tweak fest alluded to in video. Enjoy.

Here is what Stereophile measured with their quasi-anechoic method...

Those I knew of thanks. Was just curious. Anyway, I see zero sense in not performing the magic on them, since those are your primary speakers, rather than some arbitrary neutral speaker. However if you still want to do that, pretty much any Revel.
I use a pair of M16 bookshelfs for internal testing. ($900/pr)

cheers

 

[Sonnie Parker]

Burden of proof
The AES ones yes and some Directions. All, no.
Burden of proof



There is nothing "new" about claims. Nor new about folks believing said claims in lieu of a shred of evidence, while completely disregarding all evidence to the contrary, such as ears preferring neutral, which cannot be "corrected" to anything other than non-neutral, etc, etc.
And yes I'm aware of the claims about "fixing" "timing" of the onset signal magically from the contaminated, blind in room response. Also, in lieu of a shred of supporting evidence.


So do the internet switch, cable lifter, power regenerator, etc. guys.


From the moment $500 leaves your wallet, there is no scientific validity of the "test" other than anecdote. "Blind" doesn't mean "cant see". It involves knowledge of, expectations, etc. Oh, BTW, levels matter too.
But I have no doubt you'll have some listening fun, especially with the subjective post tweak fest alluded to in video. Enjoy.


Those I knew of thanks. Was just curious. Anyway, I see zero sense in not performing the magic on them, since those are your primary speakers, rather than some arbitrary neutral speaker. However if you still want to do that, pretty much any Revel.
I use a pair of M16 bookshelfs for internal testing. ($900/pr)

cheers

Well... anything we buy can be applied to your logic... and we'd all be in a world of hurt if we required burden of proof on every claim about everything we ever purchased. It's an endless list. In some cases we have to buy, try and see if we like it. Either way, both sides are making claims, neither has proven anything with testing, at least not with the new methodology.

I still can't rap my head around how I would go about using the neutral speakers to compare them, since they would likely be dynamic vs electrostats. Seems like stats would be harder to get anechoic measurements on, since the back wave is counted on to influence the sound.

 

[natty]

Spinorama measures 360 degrees around a speaker so you would be covered.

 

[AJ Soundfield]

Well... anything we buy can be applied to your logic... and we'd all be in a world of hurt if we required burden of proof on every claim about everything we ever purchased.

First, it's not "My" logic, it's just logic.
And no, not every claim is an extraordinary one, requiring proof. The can of tuna I buy doesn't claim to regrow my hair. That would be an extraordinary claim. Kapish?
Lacking is the context of the particular claim and ones knowledge of the subject of the claim. For you/99% its probably not an extraordinary claim. For Floyd et at, it is. Have you read any of the links giving the explanations as to why the claim is extraordinary??

For decades it has been widely accepted that a steady-state amplitude response measured with an omnidirectional microphone at the listening location in a room is an important indicator of how an audio system will sound. Such measurements have come to be known as generic “room curves,” or more specific “house curves.” That belief has a long history in professional audio, and now it has penetrated consumer audio with stand-alone products and receivers incorporating automated measurement and equalization capabilities. The implication is that by making in-situ measurements and manipulating the input signal so that the room curve matches a predetermined target shape, imperfections in (unspecified) loudspeakers and (unspecified) rooms are measured and repaired. It is an enticing marketing story.
It is a bold assertion that a single steady-state measurement in a room—a room curve—can reliably anticipate human response to a complex sound field. Such measurements take no account of the direction or timing of reflections within the sound field. Time-windowing the measurement is useful to separate events in the time domain, but these too ignore the directions from which sounds arrive. Human listeners respond to these cues, in some detail, and they exhibit skills in separating room sound from the timbral identity of loudspeakers, and in adapting to different circumstances. This is, after all, what happens at live, un-amplified, musical events. This means that not everything measured is perceptually important, nor can our reaction to such sound fields be constant, we adapt (see [1] chapters 5–11, and section 11.3.1, and [2] section 2.5). The simple measurements therefore cannot be definitive

For you, there is this new, untested uber tech. For me, its the same old enticing story. Context..

I still can't rap my head around how I would go about using the neutral speakers to compare them, since they would likely be dynamic vs electrostats. Seems like stats would be harder to get anechoic measurements on, since the back wave is counted on to influence the sound.

Yes, I told you about this issue before, but really, it shouldn't matter. There is no prerequisite of "neutral speakers" when paying for these "new" magic services. So just use your own, familiar sound speakers. I'm not clear what your "base" daily driver setting will be, zero EQ?
With added subs no subs? Etc.
It would also be interesting to see the before/after FRs at both LP and "speaker" only like the SP measurement.
You're not submitting this to AES, break out the Umik

Btw, since the book is taking you a while, there is also some video

cheers

 

[Sonnie Parker]

Haven't you figured out by now that I am a VERY sloooooowwwww reader AJ?

I have actually proven this with testing, although it could be my brain playing tricks on me.

 

[AJ Soundfield]

Well grab some popcorn and queue up that youtube vid

So, just the MLs or...

 

[Sonnie Parker]

Well grab some popcorn and queue up that youtube vid

So, just the MLs or...

Well... along with slow reading comes bad eyesight... and apparently my hearing is not really my hearing, or what I'm hearing is really not what I'm hearing... no wait, that's only if I were to measure his voice at my listening position. Either way, I'm really slow at watching too.

No... ML's crossed over at 50Hz plus 4 SVS SB16-Ultras for music via the SHD... then ML's crossed over at 80Hz with the same 4 SB16's and 2 PB16-Ultras for movies via the HTP-1.

 

[AJ Soundfield]

Either way, I'm really slow at watching too.

Well I hadn't watched it in a few years, so I forgot the funny part at the end tying back to the other thread, regarding EQ and Jasons M1s. Hopefully you'll eventually view it.

No... ML's crossed over at 50Hz plus 4 SVS SB16-Ultras for music via the SHD... then ML's crossed over at 80Hz with the same 4 SB16's and 2 PB16-Ultras for movies via the HTP-1.

Cool, should be interesting. That SHD unit appears to have Room EQ, so presumably system already "corrected"?

cheers

 

[Marc Lombardi]

Interesting discussion with the CEO of Dirac Research. Some of it is specific to how Dirac works, but it's also a good general discussion of time domain and frequency domain issues and possible methods of correction.

 

[Sonnie Parker]

Well I hadn't watched it in a few years, so I forgot the funny part at the end tying back to the other thread, regarding EQ and Jasons M1s. Hopefully you'll eventually view it.

Well... been reading a lot lately... lol... but I'll eventually get around to watching it.

Cool, should be interesting. That SHD unit appears to have Room EQ, so presumably system already "corrected"?

Per our phone discussion last week... you know I've made a lot of changes to the acoustics in the room... removing the front wall absorption panels, side wall absorption panels... and placing them on the back wall, double and tripling them up to make them really thick back there. I have some diffusion panels installed on the front, but have more on order. So as it stands right now, I'm not really doing anything, not even listening and nothing is corrected because I don't want to take any time to correct anything until I get it all finished... otherwise I'll just have to redo it all again after I get the diffusor panels in and installed.

I did (btw) order a couple of the large tapestries you linked me to... and have built one of the frames, attached the tapestry and have it hung on the side wall. I'll post pics in another thread once I get the other one finished.

So... lots of changes in my room since the last time you visited.

I've also been researching the Revel speakers... Salon 2, F208 and the newer F228Be... very interesting speakers and much like MartinLogan, a cult following that I haven't noticed until I started researching them.

Every time I turn around it seems like something is pointing back to Harman, and of course Toole has worked considerably with Harman. I thought (as he would suggest of so many things tied to audio) he might have some bias going on there. I know Harman references a lot of his work/studies, and he references a lot of what Harman does and offers for testing, etc... it's back and forth. I'm not a conspiracy theorist but it did run thru my mind and make me go hmmm. But then I got to thinking... perhaps Toole would never approve of the JBL SDP-75... that has the Trinnov Optimizer that provides automated multi-point Room EQ, with HARMAN optimization parameters and target responses from HARMAN X research... AND uses a single microphone at various listening positions... where there is no way measure what we are really hearing, unless of course Trinnov has come up with some sort of algorithm similar to what the $100,000 Klippel does to separate room reflections and manage to dumb it down to a price point that it can be used in a <$20K processor (no idea how much they cost).

 

[Marc Lombardi]

Well... been reading a lot lately... lol... but I'll eventually get around to watching it.


Per our phone discussion last week... you know I've made a lot of changes to the acoustics in the room... removing the front wall absorption panels, side wall absorption panels... and placing them on the back wall, double and tripling them up to make them really thick back there. I have some diffusion panels installed on the front, but have more on order. So as it stands right now, I'm not really doing anything, not even listening and nothing is corrected because I don't want to take any time to correct anything until I get it all finished... otherwise I'll just have to redo it all again after I get the diffusor panels in and installed.

I did (btw) order a couple of the large tapestries you linked me to... and have built one of the frames, attached the tapestry and have it hung on the side wall. I'll post pics in another thread once I get the other one finished.

So... lots of changes in my room since the last time you visited.

I've also been researching the Revel speakers... Salon 2, F208 and the newer F228Be... very interesting speakers and much like MartinLogan, a cult following that I haven't noticed until I started researching them.

Every time I turn around it seems like something is pointing back to Harman, and of course Toole has worked considerably with Harman. I thought (as he would suggest of so many things tied to audio) he might have some bias going on there. I know Harman references a lot of his work/studies, and he references a lot of what Harman does and offers for testing, etc... it's back and forth. I'm not a conspiracy theorist but it did run thru my mind and make me go hmmm. But then I got to thinking... perhaps Toole would never approve of the JBL SDP-75... that has the Trinnov Optimizer that provides automated multi-point Room EQ, with HARMAN optimization parameters and target responses from HARMAN X research... AND uses a single microphone at various listening positions... where there is no way measure what we are really hearing, unless of course Trinnov has come up with some sort of algorithm similar to what the $100,000 Klippel does to separate room reflections and manage to dumb it down to a price point that it can be used in a <$20K processor (no idea how much they cost).

In the video I posted above Johannson spends a lot of time talking about what can/should be corrected and what will cause more harm than good. I don't think I have read anything from Toole on Impulse Response correction, nor do I recall any of the other room correction systems talking about it.