Here's a really interesting lecture by Floyd Toole:
https://www.youtube.com/watch?v=zrpUDuUtxPM. It seems to be based on his book "Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms".
(The link was posted recently on the Roon forum, and I just got a chance to watch it through.)
It's quite long but well worth the time if you have any interest in loudspeaker design and measurement, acoustics, psychoacoustics -- and why room correction might not be such a great idea after all.
I'll have to watch that later, when I do have an hour and a half to spare.
I got interested in acoustic treatment of listening rooms back in the mid '90's and about the only reference I could find back then was Everest's 'Master Handbook of Acoustics' so I started to experiment with DIY treatments based on the recommendations in that book, especially treatment of first reflection points. Everest quotes a lot of research conducted by Toole.
Flash forward to 2008 and Toole publishes his own book, "Sound Reproduction: Loudspeakers and Rooms" and I immediately bought a copy. It was a very rude awakening because it was nothing like what I expected. It didn't explain a lot of the physical acoustics issues that Everest explained, it was far more heavily oriented towards psychoacoustics than Everest's book, it was strongly into multichannel setups rather than stereo, and Toole often used his own research, research cited by Everest, to support treatment suggestions quite different to Everest's suggestions. Amongst other things Toole stated that most people prefer to leave first reflection points untreated yet Everest was strongly in favour of treatment and I had treated my first reflection points.
For several years I put Toole's book aside, ignored it, and did nothing. Then, as I started rearranging my listening room a bit I started wondering about Toole, reread the book, and started experimenting. These days my setup is a lot closer to what Toole suggests and also has a fair bit less treatment in it. First reflection points are untreated and treatment is now limited to bass traps in room corners and one absorption panel against the wall midway between the speakers. The results are different but I prefer things closer to Toole's way of doing things than to Everest's. As is often the case, I also found it's harder to unlearn something than to learn something, it certainly took me quite a while to start taking Toole's recommendations seriously after years of following Everest's recommendations with results I was happy with.
In a lot of ways I think my big takeaway from Toole is that rooms aren't as bad as we think, or as many people seem to be set on convincing us that they are. Yes, there are problems but we tend not to notice a lot of the problems, our brains adapt for them, so in some cases what looks really bad on plots of some kind is barely noticeable to our ears. In addition, rather than simply being a cause of problems, reflections are actually of positive benefit in some ways. In a lot of ways it was thanks to Toole that my room stopped being something I had to "fix" or "correct" or fight and became something I could work with and in that process I became less concerned with dealing with fixing issues caused by physical acoustics and more concerned with making adjustments that were beneficial for psychoacoustic reasons.
I thoroughly recommend Toole's book for anyone looking for a text on room acoustics and treatment but it's a solid book, it's not always an easy read, and if you're interested in dealing with a room for stereo listening you're going to have to work out which bits are more relevant for you because Toole is definitely very strongly in favour of multichannel listening.
Thank you for the link.
Very interesting lecture and excellence scientific approach.
Thank you ! It was a wonderfully done and very illuminating presentation.