Floyd Toole's Toronto AES presentation from October 28, 2025

[RickS]

In my curator role, am cross posting the following content as it is embedded in a related thread and want to highlight for members that may have missed. 

While his books are worthwhile reading, this is a great way to get an overview direct from a major audio researcher and valued contributor.

Thanks Floyd!

 

[Floyd Toole]

Hello everybody, I just returned from giving a lecture to the Toronto section of the AES, as noted above. It was great to meet some old friends and to introduce some new audio enthusiasts to the science of audio.
The 4th edition is more than a book. It has a website - not yet accessible, but should be soon. I have already complained to the publisher.
Books are always limited by page counts and old content must be omitted to include anything new, and this time I have two extra authors. We planned in advance to have a website and the first version of it contains some historical stuff that some greybeards may find interesting, some on LP playback systems that will no doubt upset a few fans of the format. There is an expanded discussion of ITU and EBU recommendations that are in bad need of updating.
Perhaps the most important website content are some slide shows that summarize some book content, including some new material. Educators may find them useful, but I think almost anyone should scan them for an overview of specific topics. The last slide show is about "translation" and it shows spinoramas on a wide selection of pro monitors and different kinds of consumer playback devices. There are some surprises, I think. The audio world has changed for the better - dramatically.
What is now need is for people to pay more attention to trustworthy measurements and less to "opinions" formed under biased circumstances. But human nature is powerful. I focus a bit on this in my Toronto lecture, which you might find interesting. I apologize for my voice giving out near the end - age is showing . . .

I have ideas for more, and we have a window of several weeks after which we can have some revisions and new material uploaded, so stay tuned.
Cheers,

 

[wonderfulaudio]

Here he mentions to do subwoofer measurements with all subwoofers together, not individual subs

and here he mentions to do each subwoofer measurement separate

Can somebody explain, why the difference?

 

[amirm]

and here he mentions to do each subwoofer measurement separate

Can somebody explain, why the difference?

That's an explanation of the automated sub optimizer called SFM (Soundfiled Management). The previous reference was someone doing manual optimization.

 

[Keith_W]

Here he mentions to do subwoofer measurements with all subwoofers together, not individual subs

and here he mentions to do each subwoofer measurement separate

Can somebody explain, why the difference?

I gave my answer in this thread. When you want to see the result (i.e. what you hear), measure all subwoofers and woofers together. But when you are doing the tuning, each woofer and subwoofer needs to be measured separately.

 

[Floyd Toole]

OK, some confusion here, probably my fault, but I thought I made it clear that there were two basic methods of manipulating room modes. The first used two or four identical subs in rectangular rooms, where the modal structure is simple. This essentially attenuates odd-order modes, leaving strong second-order axial and tangential modes which result I standing wave nulls at the 25% distances from the walls, which one avoids, placing listers heads in the "calm" areas between. Finally equalize with all subs operating.

The second method employs signal processing in the line-level feeds to individual subs. In this method full transfer function--amplitude and phase--measurements are made from each sub location to each listener location, and an optimization algorithm will find a collection of solutions that will reduce the seat-to-seat variations, after which global EQ can be done with all subs running. In this method rooms need not be rectangular, subs can be different and location is more flexible, but fussy users might want to try a few configurations to see if there are winners and losers.

We cannot "eliminate" rooms or room modes, but we can more successfully live with them using techniques of this kind.

 

[Wesseling Audio Lab]

Audibility threshold of speaker resonances with 3 different Q's - Great Stuff!

 

[Descartes]

Thank you and Happy New Year Dr. Floyd. Wishing you good health and happiness for 2026.

I bought every edition of your book and am looking forward to seeing your website!

 

[G|force]

I finally watched this and found it very informative. It's been a long time since I attended a Synaudcon presentation and this brought back fond memories.
Thank you Dr. Toole and all involved.