• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Dr. Floyd Toole' system - with pictures

Blumlein 88

Major Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
7,833
Likes
9,399
#21
I find it very difficult to judge distances, especially in rooms, from photos.

Here, I'll guess the recliner puts the listener about 15-16 feet from the speakers, which are about 12 feet apart, using 18" floor tile squares as a guessing reference.



He mentioned earthquake-proof install.

The weight seems to be a bit much for the tweeter, which shows signs of being squashed...

On the other hand, they seem to extend well past the shelf they seem to be resting upon, so, I think they're wall-mounted and floating out farther than it looks at first glance.

View attachment 6418
Here is his answer about the distance. Sometimes he moves close to get that equilateral triangle spacing using lightweight chairs.

How far from the Salon2's is the main listening position is Floyd's room? It looks like it's way too far to get any decent stereo. I understand room constraints (and hate them), and I'm sure that has a lot to do with it.

The panoramic photograph distorts perspective. For movies the arrangement is as shown in Figure 13.18 in my book: the L & R speakers are 12 feet apart and the farthest listening distance is 16 feet.. For solo music listening I move the stereo seat forward placing my head closer to the apex of the stereo equilateral triangle. Having lightweight Scandinavian chairs not bolted to the floor has advantages. Mostly though, I listen a bit farther back and frequently add some upmixed sound to the surrounds. Right now I'm using Anthem Music mode which leave the front soundstage alone. Some recordings are better in straight stereo - it depends on the mix and the type of music. The soundstage is just fine because the L & R speakers have an unimpeded path to my ears and they are perfectly matched.
 

Blumlein 88

Major Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
7,833
Likes
9,399
#22
Controversial stuff!:)
He basically says that if your speaker is pretty neutral to start with, you can dispense with room measurements and EQ - in fact they will mess up the sound. Your hearing separates the room from the direct sound, so you can plug in your speakers, put on a CD and relax...
Yes the one thing I wonder about is him saying this about your brain separating reflections easily enough. That you mostly hear the direct sound and early reflections. Okay, but how early is early? My experience with speakers, and some measures of what constitutes early looks like his speakers are too close to some walls not to get reflected sound early enough it colors the speaker's own sound. Maybe not, but he hasn't convinced me about what one commenter said. That his speakers as they are may be good, but he might not be getting the best of them.

Thinking of a different kind of speaker, I have had reason a few times to setup a space for presentations to a small group in not such large rooms. If the person speaking was at a podium to close to the rear wall, as in just enough space to stand you had problems understanding what that person said. Move them out from the wall 4 feet and things were better in terms of intelligibility.
 

Fitzcaraldo215

Major Contributor
Joined
Mar 4, 2016
Messages
1,427
Likes
544
#23
Controversial stuff!:)
He basically says that if your speaker is pretty neutral to start with, you can dispense with room measurements and EQ - in fact they will mess up the sound. Your hearing separates the room from the direct sound, so you can plug in your speakers, put on a CD and relax...
I do not agree with him, myself. That's true even in the room containing the top line Revels belonging to my friend, to who I previously referred. My friend and I agree, it measures and sounds better with Dirac Live used full range, though we could limit it if we preferred. We do not.
 
Last edited:

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
24,147
Likes
45,433
Location
Seattle Area
#24
He basically says that if your speaker is pretty neutral to start with, you can dispense with room measurements and EQ - in fact they will mess up the sound. Your hearing separates the room from the direct sound, so you can plug in your speakers, put on a CD and relax...
Only above the transition frequencies of a few hundred hertz. Below EQ/measurement/optimization is mandatory.
 

oivavoi

Major Contributor
Forum Donor
Joined
Jan 12, 2017
Messages
1,424
Likes
989
Location
Oslo, Norway
#25
I really struggle to get my head around this room eq thing. On the one hand, some of smartest guys in audio are against correcting things above the Schroeder frequency - Bruno Putzeys, Floyd Toole, Linkwitz, and more. On the other hand, there are also some really smart people (including on this forum) who sing the praises of room eq, and there are quite a lot of listeners who report that they hear dramatic improvements with programs like Dirac, Acourate, etc (and a few who report that they think it sounds artificial). In the pro world, it is also very common for live sound egineers to "tune the room" for resonances, peaks, etc. I don't even think it's controversial in live sound reinforcement circles. It's just something that is a given. In their case, though, I think what they try to do is mostly to get down large frequency peaks. And I'm not sure if that can easily be transferred to hifi.

Sorry for the detour. Anybody knows when the new edition of Toole's book will be released btw?
 

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
24,147
Likes
45,433
Location
Seattle Area
#26
I am not super hardcore about it. My stance is that you must listen to any correction above transition and if it sounds better, by all means keep it. Harman's own research with B&W 802 speaker by the way found that correction above transition was effective. It compensated for a dip in its response that is due to poor directivity -- exactly what is NOT supposed to be correctable by EQ -- but subjectively it was. See AES paper, The Subjective and Objective Evaluation of Room Correction Products:

"As a final note, there has been much controversy
related to whether room corrections should attempt to
equalize the loudspeaker/room above the room
transition frequency (about 300 Hz). These
experimental results provide evidence that broadband
loudspeaker/room equalization above the room
transition frequency can yield positive benefits, even
when the directivity of the loudspeaker is not smooth or
constant. In these tests, both preference and spectral
balance ratings improved by filling in the 3 kHz dip in
the loudspeaker’s sound power response. The uniformly
distributed broadband acoustical treatment of our
listening room may be an enabling factor in achieving
good results with broadband equalization by minimizing
the room’s spectral tampering of the reflected sound
produced by the loudspeaker. More perceptual research
in needed to better quantify how the performance of the
acoustical treatment of the room affects the sound
quality of broadband room correction."
 

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
24,147
Likes
45,433
Location
Seattle Area
#27
Here is the result of EQ in the above research:

upload_2017-4-26_15-7-37.png


Dotted dash line is the measured, no-EQ response. The blue, green and red are the EQ systems that generated more positive response than doing no EQ. Notice how the directivity dip at 2,000 to 3,000 Hz (in dashed line) was filled in by all of them.
 

Sal1950

Major Contributor
The Chicago Crusher
Forum Donor
Joined
Mar 1, 2016
Messages
6,688
Likes
4,702
Location
Central Fl
#28
BTW guys, if you want me to reach out to Dr. Toole and get some questions answered, I am happy to do that.
Why not have him stop by the forums for a chat? :)
 

DonH56

Technical Expert
Technical Expert
Forum Donor
Joined
Mar 15, 2016
Messages
3,780
Likes
5,337
Location
Monument, CO
#29
Controversial stuff!:)
He basically says that if your speaker is pretty neutral to start with, you can dispense with room measurements and EQ - in fact they will mess up the sound. Your hearing separates the room from the direct sound, so you can plug in your speakers, put on a CD and relax...
Well, not for deep bass/subwoofer frequencies, but above, yeah...
 

Cosmik

Major Contributor
Joined
Apr 24, 2016
Messages
3,075
Likes
1,945
Location
UK
#31
Only above the transition frequencies of a few hundred hertz. Below EQ/measurement/optimization is mandatory.
Yes, he says that in his comments, and that it is only valid for a single location in the room.
 

Cosmik

Major Contributor
Joined
Apr 24, 2016
Messages
3,075
Likes
1,945
Location
UK
#32
I am not super hardcore about it. My stance is that you must listen to any correction above transition and if it sounds better, by all means keep it. Harman's own research with B&W 802 speaker by the way found that correction above transition was effective. It compensated for a dip in its response that is due to poor directivity -- exactly what is NOT supposed to be correctable by EQ -- but subjectively it was. See AES paper, The Subjective and Objective Evaluation of Room Correction Products:

"As a final note, there has been much controversy
related to whether room corrections should attempt to
equalize the loudspeaker/room above the room
transition frequency (about 300 Hz). These
experimental results provide evidence that broadband
loudspeaker/room equalization above the room
transition frequency can yield positive benefits, even
when the directivity of the loudspeaker is not smooth or
constant. In these tests, both preference and spectral
balance ratings improved by filling in the 3 kHz dip in
the loudspeaker’s sound power response. The uniformly
distributed broadband acoustical treatment of our
listening room may be an enabling factor in achieving
good results with broadband equalization by minimizing
the room’s spectral tampering of the reflected sound
produced by the loudspeaker. More perceptual research
in needed to better quantify how the performance of the
acoustical treatment of the room affects the sound
quality of broadband room correction."
Absolutely. The 'no correction philosophy' can only work for a speaker that is neutral. (Non-uniform dispersion characteristics can't be corrected as such, but they can be improved subjectively with some gentle EQ e.g. baffle step compensation which, technically, is room- and placement-dependent, so in non-adjustable non-DSP speakers can only be approximate).

But I think that is a distraction from the fundamental question: would a genuinely neutral speaker in a decent room be 'correct'? I think that many people think that it wouldn't be, and that room correction would go some of the way towards correcting that error. I disagree. There would be no error to correct and, even if there were, no way of meaningfully correlating the in-room measurements with the subjective sound.
 

Blumlein 88

Major Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
7,833
Likes
9,399
#33
I think of this as well. Some have said you should room correct below the transition. That you could EQ correct for the anechoic response of the speaker if known above that. Assuming that isn't due to weird directivity (like 1st order crossovers) I don't see how that is wrong. Sure you say but don't design the speaker that way, yet plenty of them are. I have at times experimented with doing very close measurements up close at higher frequencies trying to approach anechoic response with lessened effect of reflections. That seems to work for non-flat speakers.

Then if you have worked with various panels things are different. At least gentle contouring of the response seems very beneficial above the transition zone. Do panels and non-flat conventional speakers with wideband correction sound as good as a superb flat anechoic designs with only correction below the transition zone? I don't know. Becomes a rather complex question to answer. I am all for superb speaker design needing less noodling about the resulting sound.
 

oivavoi

Major Contributor
Forum Donor
Joined
Jan 12, 2017
Messages
1,424
Likes
989
Location
Oslo, Norway
#34
"These
experimental results provide evidence that broadband
loudspeaker/room equalization above the room
transition frequency can yield positive benefits, even

when the directivity of the loudspeaker is not smooth or
constant."
Do these quotes from Olive imply that room eq may work even better - in principle - with speakers like good omnis or CBTs? Since their directivity is very constant? That idea kind of makes sense for me, since it is more likely that eq'ing the frequency response at one place in a room will create an even response in other places in the room as well, when the speaker sends the same frequencies everywhere.
 

hvbias

Senior Member
Joined
Apr 28, 2016
Messages
439
Likes
237
Location
Northeast US
#35
I really struggle to get my head around this room eq thing. On the one hand, some of smartest guys in audio are against correcting things above the Schroeder frequency - Bruno Putzeys, Floyd Toole, Linkwitz, and more. On the other hand, there are also some really smart people (including on this forum) who sing the praises of room eq, and there are quite a lot of listeners who report that they hear dramatic improvements with programs like Dirac, Acourate, etc (and a few who report that they think it sounds artificial). In the pro world, it is also very common for live sound egineers to "tune the room" for resonances, peaks, etc. I don't even think it's controversial in live sound reinforcement circles. It's just something that is a given. In their case, though, I think what they try to do is mostly to get down large frequency peaks. And I'm not sure if that can easily be transferred to hifi.

Sorry for the detour. Anybody knows when the new edition of Toole's book will be released btw?
Bob Katz is another who advocates the use of a target curve and if I recall correctly from a post to the Acourate group he says it sounds more like what he hears in his own recording/mixing of albums. I think he was using one of the smaller Revel speakers with subwoofers (two I think?) at the time he posted that. He also advocates this with my reference headphones, and he is no doubt right that the EQ on those headphones sounds far more accurate than the stock response.

I remain a neutral observer on correction above Schroeder :)

Where did you hear a new edition of his book is coming out?
 

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
24,147
Likes
45,433
Location
Seattle Area
#38
Just to be clear, Dr. Toole is not against target curve. Indeed he talks about different EQ for different music (although the forced one, X-Curve, for theaters is one that he is against as I am). What he is admonishing is fixing the dips and peaks as those are likely caused by off-axis response that doesn't match the on-axis response. That combination cannot be fixed by EQ because you cannot just EQ the reflection (i.e. it is not minimum phase).

So EQ to taste is fine. EQ to fix what a single measurement mic shows, not so much
 

Fitzcaraldo215

Major Contributor
Joined
Mar 4, 2016
Messages
1,427
Likes
544
#39
Do these quotes from Olive imply that room eq may work even better - in principle - with speakers like good omnis or CBTs? Since their directivity is very constant? That idea kind of makes sense for me, since it is more likely that eq'ing the frequency response at one place in a room will create an even response in other places in the room as well, when the speaker sends the same frequencies everywhere.
The nice thing with better EQ tools today is that they are increasingly controllable and tweakable. So, it is fairly easy to experiment with EQ below transition vs. full range and decide. As I have said, my anecdotal subjective conclusions with decent speakers in a number of typically imperfect rooms has been to prefer full range EQ with a gentle, linear, downward slope, as also widely supported, including by the likes of Sean Olive, Bob Katz, B&K, and many, many others.

You earlier cited Putzeys, Linkwitz and Toole as being against full range EQ. Yes, they are all really smart guys, but note that they are all in the speaker business. So, I tend to think they would all prefer to solve the problem at the speaker, which they all have worked very hard at doing. Pride in their own work with speakers might bias them that way. That might even be the best way, the ideal way above transition. But, we do not all have speakers that necessarily meet the ideal.

I do not think Olive is implying better results with omnis or CBTs. I also do not think the fact that these speakers SEND the same frequencies everywhere is what is important. First, everywhere is not important. Second, it is the sound RECEIVED by our ears that is important, and that sound is influenced by the room differently at each room location. That is obviously true below the transition frequency on a narrow-band basis, but I think it is still true to some extent above the transition frequency, more on a broad-band basis.
 

oivavoi

Major Contributor
Forum Donor
Joined
Jan 12, 2017
Messages
1,424
Likes
989
Location
Oslo, Norway
#40
What "thing" about monoblocks?

I suspect he's using because he had them, and because he can, but there are technical reasons for monoblocks. Like many things audio, whether or not any of the technical advantages translate to actual audible improvements is debatable and depends very much upon other factors.
If I could pick up on this, DonH... what are the technical advantages with monoblocks? The only one that springs to my mind is 100% channel separation.
 
Top Bottom