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

[AudiocRaver]

1 - Pretty tough for a four to six inch thick absorber against a wall to have much affect on bass below 200Hz though. Absorbers work best at quarter wavelength from the reflecting surface, so even at 200Hz that's 1.4ft.

That has been my experience as well. LF response is barely affected.by the absorption.

About toeing the fronts, the best and easiest way I discover is the following forom a member Linearphase:
linearphase said:

3. Tweak the toe in and MLP to produce the best sound and most lifelike imaging. Keep things very symmetrical. if you have access to pink noise you can also play it over both speaker to confirm a good centered image. Then reverse the leads on ONE speaker. You should hear a "hole" between the speakers with the rest of the sound speed evenly out from there, ideally extending even bit outside the speakers. Tweak the toe in while at the listening position slightly. You should find one position were the noise sounds smooth AND the image just locks to a hole in the center. Don't forget to return the leads back to normal polarity when done here.

It is the second step that make a differnece (the whole in the center after reverse polarity of one speaker) which is more difficult to find but when you got it, the SS&I is better.

Very cool. The dual-mono pink noise works well. Or a favorite track mixed to mono. Have not tried the phase reversal step.

I've had what I believe is good success starting out with the speaker placement recommendations by Cardas: http://www.cardas.com/room_setup_main.php

It was not until I tried those recommendations many years ago that I actually started enjoying listening to music. The closer I am to the speakers, the better it sounds to me... and the depth is beautiful.

Whether to treat the front wall with absorption or diffusion also depends on the speakers... as it is my understanding that planar speakers like MartinLogan should have the front wall diffused.

I need to do some playing with front wall diffusion. I have been so happy with absorption that it has become my go-to front wall treatment. I seems like diffusion would soften the imaging, but I sill need to try it and compare one of these days.

Having said all that, now that I've read a good bit of Toole's book (and references to parts I have yet to read), I'm not sure what I am hearing is real or fake anymore... perhaps my mind has been playing a lot of tricks on me.

Sonnie, Sonnie, you have to BELIEVE in yourself! And your ears!

Right, he rarely mentions dipoles other than to say YMMV with them. In particular I recently read a comment like that where he was discussing the listening tests from which the proverbial Harman Curves were derived. Of course those tests were done with conventional box speakers, and I might add, commercial studio recordings of pop music (i.e. no classical or jazz recorded in live settings). I mention the latter because it seems pointless to me to discuss imaging and soundstage for recordings made with a number of close mic'ed instruments in a studio (perhaps even on different days), such that there is no "there" there, and then "mastered" to the point that all hint of dynamics has been pounded flat. Did I just digress?

Maybe just a hair... LOL. That is my favorite kind of recording, the "created from nothing" (not the smashed dynamics). Wonderful possibilities for SS&I!

 

[natty]

That has been my experience as well. LF response is barely affected

Right but if the distance between speaker and wall is very small the six inch panel behind the speaker can kill the sbir.

 

[AJ Soundfield]

I had a Lexicon DC1 for a few years with Logic 7. I liked it okay, but wasn't much into stereo music listening then.

Well, how to use it, as linked, would be critical too. As mentioned though, the primary benefit is for real acoustic spaces type music, not so much studio constructs,

I guess I need to send open letters to all of the manufacturers to provide us with valid perceptual evidence of efficacy. Got a lot of work ahead of me huh?

Only the ones making extraordinary claims without evidence. Narrows to list to just a couple magic EQ companies.

Yes... I agree... someone needs to do more testing

See above and yes they and they only, need to do. Looking forward to these revolutionary perceptual science tests upending decades of research.

cheers

 

[AJ Soundfield]

Hi Wayne, hope all is well.

It is not clear that SS&I were high priorities for Toole's work - it is an important personal goal in reading his book to see whether or not it was and how he suggests achieving it.

So you haven't yet read Tooles book? Chapters 8 & 12, etc?
I know you come from the studio side of things and probably aren't an AES member, but just FYI, Toole was testing for stereophonic spatial and image qualities in the early 80s, published this AES paper in 1985
Subjective Measurements of Loudspeaker Sound Quality and Listener Performance

cheers

 

[AJ Soundfield]

It's Groundhog Day again for links, but here goes
https://www.audioholics.com/room-ac...ons-human-adaptation/what-do-listeners-prefer
https://www.audioholics.com/room-acoustics/room-reflections-human-adaptation

http://harmanhowtolisten.blogspot.com/

 

[AudiocRaver]

I suppose it is also worth noting that while it is "toole's book," my quick estimate is that more than 80% of the research is not his. Like most good (I didn't say definitive) text books, it brings together arguably "all" of the scientific data that has been subject to processes like peer review in the field, and attempts to synthesize the data from all those pieces of research into some generalizations that the data supports. And like a lot of such text books, he is proud of his own segment of the research used and it tends to reveal his particular areas of interest.

At various points he mentions that more research in some topics and areas would help to make better conclusions on certain subjects.

Sounds like a fairly comprehensive compilation of the state of the art.

I am looking forward to finishing the book. Only a chapter in right now, just got it yesterday so I could join the discussion on even ground you all.

Right but if the distance between speaker and wall is very small the six inch panel behind the speaker can kill the sbir.

Gotcha, and now I remember you saying that in the earlier post. Thanks for clarifying.

My brain is kinda stuck in the "pull the speakers out from the wall" mode I am used to. Actually I have had some frustration with SBIR effects in the 100 Hz range that I can do very little about. I need 8 subwoofers like Sonnie.

 

[natty]

Yeah, it is worth an experiment if you have the interest. Getting the speakers very close to the wall pushes that SBIR issue up into higher frequencies so they are significantly easier to control with acoustic absorption. It may or may not be what you like/want/need in your system, of course.

 

[Sonnie Parker]

I suppose it is also worth noting that while it is "toole's book," my quick estimate is that more than 80% of the research is not his. Like most good (I didn't say definitive) text books, it brings together arguably "all" of the scientific data that has been subject to processes like peer review in the field, and attempts to synthesize the data from all those pieces of research into some generalizations that the data supports. And like a lot of such text books, he is proud of his own segment of the research used and it tends to reveal his particular areas of interest.

At various points he mentions that more research in some topics and areas would help to make better conclusions on certain subjects.

Yes, someone else make reference to his references. Look at the footnotes. He seems to bring the best of it all together in one place. Imagine now going and reading all of those references.

 

[Sonnie Parker]

Only the ones making extraordinary claims without evidence. Narrows to list to just a couple magic EQ companies.

That's a completely false and unfair statement AJ. Just because you have a vendetta with any EQ systems (even those that have yet to be tested), does not make them the only product making extraordinary claims. Their claims are not not nearly as unusual or profound as some other products I've seen advertised over the years, that have been tested ad nauseum to not have any differences in sound. Unless you are totally blind and have never read anything on manufacturer sites (and I know that's not you), you can go to numerous manufacturer websites for cables, wires, treatments, and even some DACs and amps, and see some of the claims made are indeed extraordinary.

Let's please keep the topic on Toole's book, and not about your issues with specific systems that Toole has not tested. Let's please avoid the condescending attacks on individuals and insults on those that are using the products. That's not doing anyone any good, and will cause them to ignore you. Communicating respectfully is as much of a virtue as knowledge of audio and links. I'm getting too many complaints and I'd really like to see you continue to have respectable conversations in the forum.

I need to do some playing with front wall diffusion. I have been so happy with absorption that it has become my go-to front wall treatment. I seems like diffusion would soften the imaging, but I sill need to try it and compare one of these days.

Sonnie, Sonnie, you have to BELIEVE in yourself! And your ears!

I think you'll see later on that Toole recommends more diffusion on the front wall and absorption on the back wall with stats. We can experiment later when you visit.

To clarify... I believe in myself, but my ears... well, that's another thing of course. That comment I made about not really hearing what I'm hearing was intended to be sarcastic.

Looking forward to more of your thoughts as you continue to read the book.

 

[AJ Soundfield]

That's a completely false and unfair statement AJ. Just because you have a vendetta with any EQ systems (even those that have yet to be tested), does not make them the only product making extraordinary claims. Their claims are not not nearly as unusual or profound as some other products I've seen advertised over the years, that have been tested ad nauseum to not have any differences in sound. Unless you are totally blind and have never read anything on manufacturer sites (and I know that's not you), you can go to numerous manufacturer websites for cables, wires, treatments, and even some DACs and amps, and see some of the claims made are indeed extraordinary.

Not in the context of the entire discussion about EQ. Not a single mention from me about all those other things you mentioned.
Almost everything I've linked to regarding Toole was about EQ..not dacs, etc.
Vendetta?? That's your misread sir. I have repeatedly said its often better than no EQ. Just by fixing the bass alone, which some seem to do well! Even included listening tests preference scores. Ya missed those too??

I'm getting too many complaints

Thanks for letting me know, I can guess from who


cheers

 

[Sonnie Parker]

Not in the context of the entire discussion about EQ. Not a single mention from me about all those other things you mentioned.
Almost everything I've linked to regarding Toole was about EQ..not dacs, etc.
Vendetta?? That's your misread sir. I have repeatedly said its often better than no EQ. Just by fixing the bass alone, which some seem to do well! Even included listening tests preference scores. Ya missed those too??


Thanks for letting me know, I can guess from who


cheers

You replied to my comment, which was not solely in the context of EQ... it was about all equipment.

I can assure you I haven't missed any of it AJ, and I am only addressing what needs to be addressed. You can't dress up a repeated whole lotta negative with a little bit of positive from time to time.

Vendetta is not actually my word, and I promise you I'm not the only one misreading you. It's pretty clear with the message you are sending. The complaints are not coming from anyone who has anything to do with the people that are associated with those products/companies (if that is who you are guessing of the four different complaints I have received), as I can assure you, they ignore you because they don't believe anything they say or do will change your mind.

Just relax a bit about it all, you don't have to keep pounding on them. Once again, you haven't even went thru the process and listened to some of these newer methods. No reason to be belligerent with them all. If someone did do testing of them and found them sufficient, you'd probably find issue with the test (seem familiar?).

This ends here and now... let's keep the thread on topic so we can continue to be friends and have civil respectable conversation.

 

[AJ Soundfield]

they ignore you because they don't believe anything they say or do will change your mind.

Guilty as charged, since I require evidence, not say so.

Once again, you haven't even went thru the process and listened to some of these newer methods.

Certainly not the ones that don't come with hardware like on my Lexicon, Denon, etc. True. I have not tried any software only versions.
However "newer" to you, might not be "newer" to me. Is all about understanding of the basic electro-acoustic issues. None of which are new. After all the fancy words, its all electrical input to the speaker terminals. No more, no less.

If someone did do testing of them and found them sufficient, you'd probably find issue with the test (seem familiar?).

Not at all and an unfair accusation. I have repeatedly said if the evidence gathered is valid (AES, ASA, etc paper), I would have to accept it and hopefully have it further validated by repeat. That's very, very basic scientific protocol. Precisely why I'm a member of both.

This ends here and now... let's keep the thread on topic so we can continue to be friends and have civil respectable conversation.

Fair enough, hopefully the thread pauses until people actually read what Toole wrote, which as noted, is heavily about what others, not "him" have found. Just nicely compiled all in one place, not behind an AES, etc paywall.
Happy reading!

cheers

 

[AudiocRaver]

I think you'll see later on that Toole recommends more diffusion on the front wall and absorption on the back wall with stats. We can experiment later when you visit.

And no doubt he will show his evidence supporting that arrangement. Intuitively, it seems like diffusion in front would soften image clarity, and that absorption in back would deaden delayed reflections which could enhance spaciousness of sound in the room. Toole refers to acoustical concert instruments, their size, their ability to radiate sound in all directions, and the audience members' sense of "air" around such instruments, as Apparent Source Width (ASW). Perhaps his findings support an approximation of that effect in one's listening room.

It will be interesting to play with, and I will probably do some of that in my room to get my feet wet. I read on...

 

[Sonnie Parker]

And no doubt he will show his evidence supporting that arrangement. Intuitively, it seems like diffusion in front would soften image clarity, and that absorption in back would deaden delayed reflections which could enhance spaciousness of sound in the room. Toole refers to acoustical concert instruments, their size, their ability to radiate sound in all directions, and the audience members' sense of "air" around such instruments, as Apparent Source Width (ASW). Perhaps his findings support an approximation of that effect in one's listening room.

It will be interesting to play with, and I will probably do some of that in my room to get my feet wet. I read on...

I should clarify that statement, since I have not gotten that far in the book as of yet, and why I stated "I think you'll see later". It is based on what someone told me on the phone and who has read the book and studied Toole's various studies, papers, etc.. And the assumption that he discusses it at some point in the book since he discusses acoustic treatments. If we learn it's not in this book, then I should be able to find out where he discusses it more specifically.

I can confirm that Glenn Kuras of GIK has publicly suggested diffusor panels for front walls for electrostatic speakers. I suspect he might know a little bit about it, but I have not seen or read any official tests to support one way or another.

 

[AJ Soundfield]

I should clarify that statement

No.
If this goes awry we are both blaming this on Toole.
Just fyi

 

[Sonnie Parker]

No.
If this goes awry we are both blaming this on Toole.
Just fyi

That's good to know... I wasn't losing faith in you, just verifying I have not actually seen it with my own eyes yet, strictly going by faith.

 

[AJ Soundfield]

Well, in truth, this is also recommended by Mr Dipole Linkwitz (RIP) himself.
So that's 2 people to blame other than me. Fyi.

 

[Sonnie Parker]

Good article... and I just read where Toole references Linkwitz in chapter 7.

 

[AudiocRaver]

Hi Wayne, hope all is well.


So you haven't yet read Tooles book? Chapters 8 & 12, etc?
I know you come from the studio side of things and probably aren't an AES member, but just FYI, Toole was testing for stereophonic spatial and image qualities in the early 80s, published this AES paper in 1985
Subjective Measurements of Loudspeaker Sound Quality and Listener Performance

cheers

Hi AJ, doing will. Still reading, I just got started over the weekend. Have a ways to go....

 

[AJ Soundfield]

Hi AJ, doing will. Still reading, I just got started over the weekend. Have a ways to go....

Good to hear. Been a while.
Confession, I read the book a while back, don't have it memorized. It's huge!
There is a lot of info there. I do tend to conflate whats in it with my own decades of reading research, not all in the book, AES, ASA, etc that significantly dwarf what's there. The AES e-library is my home away from home.
That said, for a "speed read" (Sonnie, cough, cough), in your particular area of interest, try this https://www.audioholics.com/room-ac...ons-human-adaptation/what-do-listeners-prefer
It mentions the test I linked along with a few others regarding SSI.
The book is more comprehensive and of course, if you want off the deep end, the AES e-library is $125/yr, a bargain IMHO.
Happy reading (Sonnie probably still hasn't finished the hour long Toole Youtube vid I linked )

cheers

 

[Sonnie Parker]

I'm just trying to keep up with reading posts.

 

[JStewart]

I'm now an official member of the circle of confusion. 500 pages, Yikes.

@AJ Soundfield you'll be proud of me. With the HTP-1 pre-pro I had the ability to turn off Dirac and EQ all speakers below 250Hz (9 of them) using REW of course and MMM to get the average SPL at the MLP. I'd also been only aligning phase with REW for 4 subs and letting Dirac handle from there, so re-did with MSO. Then aligned mains to subs at the XO. A bit of work.

Obviously one person's subjective experience on SQ means absolutely nothing, but I've probably watched 6hrs of movies and listened to a couple hours of music since and it sounds fine to me. The ASW seems wider. The imaging just as good. I can switch back and forth between the set-ups to compare, but it takes a couple of minutes. Admittedly, this does not prove anything other than my personal enjoyment is the same or marginally better at the moment without Dirac.

I've been a Dirac user for a while and in the past I've not had the same impressions (eq'd with miniDSP), so perhaps it could be due to my newest speakers, JTR 210RTs in my small room (Matthew Poes did measurements for the 212RT which uses the same horn, with the same mid and tweeter HERE) or it could be that I'm just imagining the whole thing which is just as likely, LOL.

 

[AJ Soundfield]

I'm now an official member of the circle of confusion. 500 pages, Yikes.

The ASW seems wider. The imaging just as good.

perhaps it could be due to my newest speakers, JTR 210RTs in my small room (Matthew Poes did measurements for the 212RT which uses the same horn, with the same mid and tweeter HERE) or it could be that I'm just imagining the whole thing which is just as likely, LOL.

Well, if your speakers measure like what Matt showed, they are effectively neutral. As I've tried to explain, LP EQ + neutral = non neutral.
It would be interesting to show REW gated sweeps at 1m and LP with/without EQ to show the differences...and why no sane loudspeaker designer would design from 3m away in a reflective room. Someone emailed me this https://www.audiosciencereview.com/...-dispersion-speakers.20850/page-2#post-698053
"Newness" has no relevance to time and frequency domain issues.
Enjoy the neutral sounds.

cheers