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What’s Your Triangle in Stereo Speaker Listening?

Which triangle is your stereo speaker setup?

  • Total voters
    175
My setup is currently super wide spacing Isosceles. But it's only been a couple of days.

Just found this thread after doing some experiments with my setup. I've been using a center channel with very narrow spacing and a cross talk altering channel mixing array for almost 2 years now. I decided after going to the Pacific Audiofest that I needed to explore a standard 2 channel listening triangle again and try to re-create the common problems with the phantom center that I thought I was hearing at the show. Trying different arrangements I was surprised to find that a very wide setup works best to my ears in my room. My guess is that it's because of improved head shadowing, but to prove that I'll need to put some microphones in my ears and see if the comb filtering is really being reduced.
In any case, I've been amazed at the solidness and clarity of the center image with my speakers about 16 feet apart while I'm sitting about 5 feet back from the plane of the speakers. Common sense suggests that the center will become dull and unclear with such wide spacing but I seem to be experiencing the opposite. I don't know if the fact that I'm using some highly directional horns makes a difference. One test I do is to listen in the sweet spot to vocals with the phantom center solidly located mid sound field, and then move to the left or right to allow one speaker to dominate. Almost always I hear a clearer, purer sound when I get closer to one or the other speaker. With this ultra wide setup I hear very little difference in presence, clarity, and tone. The image just shifts over toward the closer speaker. The other effect is I get a really wide soundstage, similar to what happens with crosstalk reduction.
 
Is there any value in the thought that as you make the leg between the speakers longer you might reduce ear-to-ear crosstalk (tending towards, but not reaching, headphone-like stereo separation)?

Conversely as the between speaker leg gets shorter a larger component of the sound from the left speaker will be able to reach the right ear.

Aside from the conceptual neatness of the idea of an equilateral triangle is there actually any scientific reason for it? Or is it just audiophile woo? Is the value of using an equilateral triangle primarily as a sort of standardisation? If so, which documents define this standard?
 
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-Matt- said:
Is there any value in the thought that as you make the leg between the speakers longer you might reduce ear-to-ear crosstalk (tending towards, but not reaching, headphone-like stereo separation)?

Conversely as the between speaker leg gets shorter a larger component of the sound from the left speaker will be able to reach the right ear.

Aside from the conceptual neatness of the idea of an equilateral triangle is there actually any scientific reason for it? Or is it just audiophile woo? Is the value of using an equilateral triangle primarily as a sort of standardisation? If so, which documents define this standard?
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I just took a look at The New Stereo Soundbook, by Ron Streicher and F. Alton Everest. On page 14.11 there's a section called Stereo Geometry. It doesn't go in to a lot of detail, just says "It is generally agreed that a roughly equilateral triangle should be used..." Throught chapter 14 "Optimizing the Listening Environment" they consider a lot of factors besides just optimal imaging at the sweet spot. From what I've come to understand the equilateral triangle has been arrived at by general consensus. There may be some harder science somewhere to justify that arrangement in most cases.

I do think it's true that you get better head shadowing with a wider spacing, and you get better phase difference across the head at lower frequencies. There's also the issue of the angle that the high frequencies are entering your ears, so there's a bigger mismatch in terms of HRTF for sounds that are supposed to be coming from straight ahead than when the speakers are more narrowly spaced.
 
There is one studio standard and that is an equilateral triangle, so everyone should use that if they are interested in hearing how most mixes were intended to be heard.
 
goat76 said:
There is one studio standard and that is an equilateral triangle, so everyone should use that if they are interested in hearing how most mixes were intended to be heard.
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There is difference between a generally accepted rule of thumb and an international standard (defined by ISO for example). If there is a studio standard what is its document number?
 
goat76 said:
There is one studio standard and that is an equilateral triangle, so everyone should use that if they are interested in hearing how most mixes were intended to be heard.
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That's a very good point. This listening triangle question reminds me of the debate about how far back you should sit from your TV based on its size. 4K was ridiculed, and maybe still is, as excessive because you're not supposed to sit that close to your screen that you'd be able to see all that detail. But some people want a more immersive experience. I find 8k excessive because I have to wear reading glasses to focus if I'm close enough to an 85" screen to see that much detail! Maybe that's an exaggeration, but I've done that at BestBuy, and it was kind of amazing to focus on one small part of a scene of a festival and see so much detail. I'd have to watch it over and over, watching different parts of the screen each time to take it all in. As the equipment expected to be used by the end-user changes, I would expect the content to be adjusted to some degree. So many people are listening on headphones now it makes me wonder if that's become a more important mixing tool.

I think there's something to the actual size of the triangle as well. Listening in really big rooms at the Pacific Audiofest, I was able to stand 30 feet back from speakers that were something like 20 feet apart. The actual angle of the triangle was narrow, but the soundstage still seemed 20 feet wide. It's like standing back a ways from a really big screen. It still looks like a really big screen.
 
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-Matt- said:
There is difference between a generally accepted rule of thumb and an international standard (defined by ISO for example). If there is a studio standard what is its document number?
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From what I've been told by some people who do it is that they listen on a variety of different configurations. Look at a mixing/mastering station and you'll often see multiple sets of very different speakers in different arrangements, and some headphones floating around too. I usually see something that looks more or less like an equilateral triangle.
 
-Matt- said:
Aside from the conceptual neatness of the idea of an equilateral triangle is there actually any scientific reason for it? Or is it just audiophile woo? Is the value of using an equilateral triangle primarily as a sort of standardisation? If so, which documents define this standard?
Click to expand...
Do you mean standards like this? https://tech.ebu.ch/docs/tech/tech3276.pdf
-Matt- said:
Is there any value in the thought that as you make the leg between the speakers longer you might reduce ear-to-ear crosstalk (tending towards, but not reaching, headphone-like stereo separation)?
Click to expand...
I had mentioned this publication in a different context (https://www.audiosciencereview.com/...ustics-links-and-excerpts.51487/#post-1854024), but you might find it interesting: https://www.researchgate.net/public...ENT_FOR_OPTIMISED_PHANTOM_SOURCE_REPRODUCTION
 
-Matt- said:
There is difference between a generally accepted rule of thumb and an international standard (defined by ISO for example). If there is a studio standard what is its document number?
Click to expand...

It doesn't have to have a document number to be a studio standard and it's way beyond anything you should call a "rule of thumb". Just have a look in the manual of studio monitors and you will see that pretty much every one of the manufacturers is describing an equilateral listening triangle, and that is what most users will follow when they set up their studio monitors which they use to create the stereo mixes with. The standard goes so far back in time that it must be considered one of the most well-known standards when talking about stereo speaker setup, as everyone interested in proper stereo reproduction knows about it. I don't think many people will argue against that. :)
 
goat76 said:
It doesn't have to have a document number to be a studio standard and it's way beyond anything you should call a "rule of thumb". Just have a look in the manual of studio monitors and you will see that pretty much every one of the manufacturers is describing an equilateral listening triangle, and that is what most users will follow when they set up their studio monitors which they use to create the stereo mixes with. The standard goes so far back in time that it must be considered one of the most well-known standards when talking about stereo speaker setup, as everyone interested in proper stereo reproduction knows about it. I don't think many people will argue against that. :)
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According to Robert E Greene, there is a theoretical or mathematical argument to be made for 90 degrees of separation for accurate reproduction of Blumlein recordings, though this is not discussed in the patent.
 
youngho said:
According to Robert E Greene, there is a theoretical or mathematical argument to be made for 90 degrees of separation for accurate reproduction of Blumlein recordings, though this is not discussed in the patent.
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That may be true, but there is also a reason why pretty much no one has ever heard of that, it never became a standard.
 
goat76 said:
That may be true, but there is also a reason why pretty much no one has ever heard of that, it never became a standard.
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I find it difficult to respond to this reply in any meaningful way, but I imagine that @j_j might have fascinating historical or psychoacoustic insights into this. I think that it's also possible that sometimes standards start with choices, which are not entirely arbitrary, but may be influenced by rounding or simplification, so the neonatal period is defined up to 28 days of life or term pregnancy is 39 to 40 and 6/7 wks of gestation. An equilateral triangle is extremely easy to set up, whereas a right triangle setup requires a protractor or the Pythagorean theorem.
 
Equilateral at about 10 feet, 3,048mm
 
My original setup in this room was isosceles with speakers set wider (2.1 metres between tweeters vs 1.8 metre sides to approx centre of listener's head). This followed the manufacturer's recommendation and also gave a better result wrt certain lateral/oblique room modes (in the 70-100 Hz range) compared to a 1.8 metre equilateral.

Changing furniture later on resulted in an equilateral setup (not moving the loudspeakers though just with the seating a bit further back). Triangle sides now all 2.1 metres approx. I'd set the speakers a bit wider but there's a post in the way.

But I've also checked scalene because in practice people sit all over the place, and when someone else (human or feline) sits down first, my listening position adjusts accordingly (if I'm feeling accomodating).

Speakers are toed-in to align with the triangle. In all the above cases the stereo image is acceptably coherent, you really have to avoid the triangle for that to collapse.
 
It is important to realize that realistic miking and speaker positions are not necessarily "the same".

More than that is hours of fiddly details.
 
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