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Speaker Testing: why mono is better

Inner Space

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I would test measure each channel separately to make sure I know of variations between them. What that has to do with the topic at hand, I don't know.

That's all I'm asking - test both transducer channels to make sure you know of variations between them. You don't see what that has to do with the topic at hand?
 
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amirm

amirm

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Just to make sure I understand correctly, are you saying that you cannot "produce defensible, highly reliable conclusions" about spatial quality from your directivity measurements and/or mono listening
Correct. I could throw out generalizations but not sure that is very useful. There are exceptions of course such as when I measured the Canon Omnio speaker, the Magnepan LRS, etc.
 

abdo123

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That's all I'm asking - test both transducer channels to make sure you know of variations between them. You don't see what that has to do with the topic at hand?

Electric circuits have an interconnected topology to support two channels, while a speaker is designed, built and tested as an individual unit by the designer. your reasoning doesn't make any sense.
 
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amirm

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That's all I'm asking - test both transducer channels to make sure you know of variations between them. You don't see what that has to do with the topic at hand?
No because a stereo microphone and how it captures a sound field is quite unique to sound recording, not reproduction.

With headphones I do measure both channels at once because both come to me at once. With speakers, due to logistics and costs, 95% of the time I only have one speaker to test. Even if I had the other, I could not do what you ask. The time on a $100K measurement system has an opportunity cost. No way I would waste it to test another sample of the same speaker, versus testing another speaker for which we have no measurements at all.

You all could write $100K checks yearly for me to hire interns and have them test more redundant things. Until then, you are stuck with what I can do which is already 100X of what anyone else is doing.
 

Duke

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Correct. I could throw out generalizations but not sure that is very useful. There are exceptions of course such as when I measured the Canon Omnio speaker, the Magnepan LRS, etc.


Thank you.

I'm still interested in any comments you have about my other question:

In post #127 you wrote, "Research shows that mono testing is more accurate than stereo testing."

Is that statement true for spatial quality?

Some performance aspects may be left on the table and that is fine.


Agreed!
 
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amirm

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In post #127 you wrote, "Research shows that mono testing is more accurate than stereo testing."

Is that statement true for spatial quality?
Yes and no. We can easily quantify dispersion of a single speaker using mono testing. I actually don't know how to do that effectively using stereo. Outside of that, I just don't know.
 
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amirm

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amirm

amirm

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Does Mono testing give better results for headphones too?
Given the isolation between the cups, the interactions we worry about with stereo speaker testing is not there. Indeed, I find that tonality tests are much easier with headphones than speakers.

As I explained when this question was asked earlier :), at some point I do like to test in mono to see if more insight can be had. For now, the system is working so I keep doing it.

With headphones, it is mandatory in my book to provide subjective commentary on spatial qualities so I have to listen stereo anyway.
 

Duke

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"Research shows that mono testing is more accurate than stereo testing."

Is that statement true for spatial quality?

Yes and no. We can easily quantify dispersion of a single speaker using mono testing. I actually don't know how to do that effectively using stereo. Outside of that, I just don't know.

Thank you very much.

Let me rephrase my question because I can now see that it was ambiguous. (I knew what I was talking about, and that makes one of us.)

I'm not asking whether you could realistically do stereo testing (whether "testing" means listening or measuring or both).

I'm asking for your opinion on whether mono testing (listening or measuring or both) is a more accurate predictor of stereo spatial quality than stereo listening is.
 
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DonH56

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That's all I'm asking - test both transducer channels to make sure you know of variations between them. You don't see what that has to do with the topic at hand?

"All"? Testing variations among samples of speakers is not the same thing as testing in stereo. It would double the work, at a minimum for two samples, and isn't really the point at this time AFAIK. Just testing one is quite a chore. I'd rather the time be spent testing more, different, speaker models than attempting to asses manufacturing variability.

@amirm -- No good deed goes unpunished.
 

NTK

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According to Dr Toole, 2 channel "stereo imaging" is dependent on room and on the recording. So the materials used for testing is another big confounding variable too.

Toole.PNG
 

Inner Space

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"All"? Testing variations among samples of speakers is not the same thing as testing in stereo. It would double the work, at a minimum for two samples, and isn't really the point at this time AFAIK. Just testing one is quite a chore. I'd rather the time be spent testing more, different, speaker models than attempting to asses manufacturing variability.

Yes, understood, of course, and I agree, building up a bigger database would be good, albeit with certain data unreported. But I didn't ask for anything to be tested in stereo - I said good stereo performance includes but is not completely defined by attributes apparent in mono, so let's expand the mono testing to include a couple of extra headline items, to give us some extra guidance.

The argument against doing that is about cost, time, and inconvenience, not about engineering - always the limitation faced in a hobby context, as opposed to a professional context. Can't we admit that, instead of trying to pretend it's something else?
 
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amirm

amirm

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The argument against doing that is about cost, time, and inconvenience, not about engineering - always the limitation faced in a hobby context, as opposed to a professional context. Can't we admit that, instead of trying to pretend it's something else?
You can admit anything. I am guided by science and research which I quoted in the video, provided links to, showed quotes, etc. that directly counter your position:

1616974769573.png


Maybe you tell us next that Harman does speaker research as a hobby and their multi-channel listening room doesn't exist, etc....
 

Coach_Kaarlo

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Dogma in the broad sense is any belief held unquestioningly and with undefended certainty. It may be in the form of an official system of principles or doctrines of a religion, such as Roman Catholicism, Judaism, or Protestantism,[1] as well as the positions of a philosopher or of a philosophical school such as Stoicism. It may also be found in political belief systems, such as communism, progressivism, liberalism and conservatism.[2][3]

In the pejorative sense, dogma refers to enforced decisions, such as those of aggressive political interests or authorities.[4][5] More generally, it is applied to some strong belief which its adherents are not willing to discuss rationally. This attitude is named as a dogmatic one, or as dogmatism; and is often used to refer to matters related to religion, but is not limited to theistic attitudes alone and is often used with respect to political or philosophical dogmas.
 

Inner Space

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You can admit anything. I am guided by science and research which I quoted in the video, provided links to, showed quotes, etc. that directly counter your position:

View attachment 120867

Maybe you tell us next that Harman does speaker research as a hobby and their multi-channel listening room doesn't exist, etc....

That doesn't counter my position at all. I don't dispute the sentence you highlighted. For avoidance of doubt - YES, mono listening tests are more revealing of loudspeaker-room artifacts. AND they're more revealing of timbre and tonality issues. And so on.

But - mono listening tests do NOT reveal several specific issues pertinent to satisfactory performance in stereo. I'm sure Harman is perfectly aware of that.
 

Postlan

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Yeah, stereo speakers are actually nothing but those stupid looking 3D glasses that we wear in movie theatre, and we adults are talking about which 3D glasses are better all day long in audiophile forums. lol.
 

richard12511

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The argument against doing that is about cost, time, and inconvenience, not about engineering -

I disagree. Science shows that mono testing is better for comparing speakers objectively. I've hosted both mono and stereo blind tests and my personal experiences have been inline with this. Mono makes it much clearer and easier to decide which speaker you prefer.

It probably seems like I've been arguing against mono testing, but that's not the case. Just to make my position more clear, my only skepticism comes from absolute statements about mono vs stereo. I'm not totally convinced that there can be no edge cases.

*Edit: @amirm not sure why it says I quoted you. Guess I messed up the ctrl + x. Meant to quote @Inner Space
 
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