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3rd edition of Floyd E. Toole's "Sound Reproduction"

I tried Toole's boundary placement recommendations for subs and although it might meet his scientific requirements i.e. evening out of amplitude response around the room, it ignores my scientific requirements of accurate transient response and time alignment.

Can you please explain the science you use to define and determine "accurate" transient response?
 
PS I kind of regret knocking Toole, I’m sure it is a great book.

It is worth reading.

I just have the mindset that if the science is just wrong, as it was in that particular dem, and it is being used to “objectively” belittle either subjective listening or a competitors product then I’ll call it out. I’m all for proper impartial science though, but that means any blind dems of speakers have to put the things exactly where that design is intended to be and meet any other operational requirements. That kind of thing just really bugs me!

And I totally agree with you - I think your concern is more than reasonable.
 
Where should Harman have placed a dipole speaker, from their set up, it looks as if there is at least a metre between the speakers and the rear wall when actually playing, each speaker is auditioned from exactly the same position ,volume matched and the ‘next’ speaker can be auditioned within a few seconds .
I would really enjoy having a similar system here.
Keith
 
IME the appropriate distance from wall behind speakers depends on the speakers as well as room, and I'd like this to be factored in?
 
Where should Harman have placed a dipole speaker, from their set up, it looks as if there is at least a metre between the speakers and the rear wall when actually playing, each speaker is auditioned from exactly the same position ,volume matched and the ‘next’ speaker can be auditioned within a few seconds .
I would really enjoy having a similar system here.

It was PR bullshit Keith, you really should see that. Every experienced audiophile knows positioning speakers for best response takes some considerable time and effort. I know you belong to the current flavour of the month mindset that believes you can position anything anywhere and just mangle the response with digital filters later to attempt to flatten/mitigate awful placement, but the vast majority of us don’t! Any credible audio reviewer would certainly try several positions for any loudspeaker before forming an opinion on it, and as such I’d expect anyone attempting to form a scientific argument would do similar. There is never one place in a room that works with all speakers. I’ve witnessed many rigged dems in my time and I’d rank that Harman one as one of the more obvious ones to be honest.
 
Where should Harman have placed a dipole speaker, from their set up, it looks as if there is at least a metre between the speakers and the rear wall when actually playing, each speaker is auditioned from exactly the same position ,volume matched and the ‘next’ speaker can be auditioned within a few seconds .
I would really enjoy having a similar system here.
Keith
For his comparison to have any validity each speaker should have been positioned in the position which shows them off to their best advantage. IME Martin Logan’s are very critical in terms of relationship to all the walls in the room and also in combination the tilt and toe in.

Clearly his comparator works fine for what he considers to be a good speaker, but there are other ways of doing things which bring an entirely different setup method. As such his comparator appears to work as a self fulfilling prophecy to the benefit of the speakers he was involved with.

He makes a reasonable case for the benefit of a speaker which doesn’t have a small sweet spot, but for the single listener that doesn’t apply. I wonder how his listening panel would have reacted to a comparison of a pair of Martin Logan’s carefully positioned in a decent room with a pair of what he considers the ideal. They might just have realised the difference between an illusion of real performers making music and a facsimile delivered via hifi. Not quite so easy to quantify perhaps.
 
It was PR bullshit Keith, you really should see that. Every experienced audiophile knows positioning speakers for best response takes some considerable time and effort. I know you belong to the current flavour of the month mindset that believes you can position anything anywhere and just mangle the response with digital filters later to attempt to flatten/mitigate awful placement, but the vast majority of us don’t! Any credible audio reviewer would certainly try several positions for any loudspeaker before forming an opinion on it, and as such I’d expect anyone attempting to form a scientific argument would do similar. There is never one place in a room that works with all speakers. I’ve witnessed many rigged dems in my time and I’d rank that Harman one as one of the more obvious ones to be honest.
You considerToole/Olive’s research’s as bullshit?
I believe in speakers which least interact with the room, speakers designed to be used close to walls and whose can be adjusted cording to position.

Keith
 
You considerToole/Olive’s research’s as bullshit?

I was commenting on one Harmon presentation that can only sensibly be viewed as a marketing talk as it promoted Harman product over others by “testing” it in situations that obviously favoured it over otherwise competitive product. If I was looking to market myself as an academic/science writer there is no way in hell I’d have put my name to such flawed test methodology. I am making no comment on anything beyond this single point, i.e. I have no viewpoint on his other work.
 
As a previous Martin Logan owner Tony, which part of the speaker would have been optimally placed (or not as you are suggesting)? The bass unit or the panel?
 
Have you considered that any speaker which radiates as much energy from the rear as from the front and has minimal but ragged off-axis response just might not be a particularly worthwhile design?
Keith
 
Have you considered that any speaker which radiates as much energy from the rear as from the front and has minimal but ragged off-axis response just might not be a particularly worthwhile design?

When the Quad ESL, a speaker I rank as one of the worlds best ever, fits that category, no, not for a second! Have you ever felt you are placing convenience/laziness over a pursuit of real excellence?

Panels have some very real advantages over multi-driver boxes. If you were prepared to set things up properly in a good sounding room I’m sure you would hear them! Quad, Magnepan, Martin Logan, Apogee, Accustat etc have all produced designs that rank with the worlds very best. These are true benchmark designs.
 
Hybrids?

i-zw2n4zM-X2.jpg
 

Personally I prefer full-range panels to any panel top/box bass speaker I’ve ever heard, but that isn’t the point here as this isn’t about my taste in speakers. I’m just criticising what I see as a marketing-led dem methodology.

PS I should also point out I like JBLs too, the bigger and hornier the better, so I’m not slagging the promoted product either.
 
Looking at the picture Tony, I would say that both the Project Array and the large Logan offer controlled dispersion (30 deg. in the case of the Logan and 60 deg in the case of the Harman product. At listening distances in that room, and the acoustic treatment, I would be surprised it there were that greater difference but am happy to be wrong.

JBL Project Array

510JBLfig5.jpg


Martin Logan Prodigy

Mlpfig3.jpg


BW 800D

511B800fig5.jpg


The JBL offers some issues around the crossover point as does the B&W. The Logan however is nowhere near as consistent or smooth - even on axis.

This isn't about which speaker is best BTW - it's just your calling the methodology into question. The picture suggests there is little wrong to me.
 
I believe in speakers which least interact with the room, speakers designed to be used close to walls and whose can be adjusted cording to position.

All speakers interact with the room to some extent. What then matters is the details of how they do so. Given this, panels differ from standard 'cones and box' designs, but each interacts in their own ways. Given this 'least' is better viewed as 'most suitable for the situation/user' not some kind of one-definition 'least'. If a speaker radiates, it will interact with the room.
 
Have you considered that any speaker which radiates as much energy from the rear as from the front and has minimal but ragged off-axis response just might not be a particularly worthwhile design?
Keith

Short answer: No. :)

Longer answer: Well, if you are referring to the ESL63 I'd suggest that people have a look at

http://ukhhsoc.torrens.org/makers/QUAD/Manuals_and_Diagrams/ESL63/Directional.gif

as that shows the directional patterns for the ESL63. (Being a panel it is fairly symmetric front-back.)

Given that the levels well away from the axis tend to be small, then the amount of 'ragged'-ness seems to me not to be particularly significant. The situation for most cones-in-box speakers are rather more variable with freqency given panel resonances, edge effects, handovers from different sized drivers, beaming, etc.

So I think we disagree on this matter. :)
 
I think people are missing the rather salient point that this wasn't a hifi review, the speaker brand(s) was secret until someone deduced from the plots it was an ML. Furthermore the research wasn't there to establish the JBL's(or Revel's) as superior but rather to establish/demonstrate the listener/measurement preference trend. A poorly placed ML or Quad will sound crap partly because and in support of the JBL/Harman research. I'd wager that correctly positioned the plots will be closer to the Harman ideal and be reflected in the listener preferences..
 
At my university, sometime in the mid-Eighties, I attended Dr. Toole’s lecture on the Compact Disc. His response to my post-lecture defense of the LP was polite but baffled. With me, having heard by then a good sampling of the first and second generation CD players, the incomprehension was mutual.

After many years at our country’s National Research Council, Dr. Toole left for Harmon, where presumably he could put his theories into practice. I am conscious that peer-reviewed science needs support. But who has come away from auditioning a Harmon system thinking the experience their best of reproduced music? Has anyone auditioned Dr. Toole’s home system?

I guess I’m asking how one evaluates a pudding cookbook?
 


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