Why evaluating the sound of a single speaker is essential

[sceptical1]

Can you elaborate.
Forget the equal loudness mention since there is no doubt that being highly exaggerated or outright non existent it gets diminished in level the wider the average speaker's frequency response is. In any case you can't deny any equalization needed at high frequencies no matter the listening level is a complete fabrication.

 

[Heinrich]

Maybe I'm mistaken to see a correlation between such observations and equal loudness curves; that certainly seems to be a disputed correlation to make. My observations are in the same general ballpark as both of yours.

This is a 'might be' reiterated, but I would expect the correlation explained as a chain of causation.

David Griesinger finds that time coherence (phase coherence + arrival time coherence) is desirable north of 1 kHz; his field is concert hall acoustics and psychoacoustics but I think the same psychoacoustic principles apply. I recall Earl Geddes saying that multiple sensitivities peak around 4 kHz, including sensitivity to diffraction.

And a new topic in the same pattern. I'm lost, don't kown what it is all about. What makes a speaker 'good' as a most general quest?

What this thread was about in the beginning is 'mono' evaluation at least as an additional tool.

My caveats, lacking a clear hypothesis that could possibly, as a scienticfic endevour, be scrutinized are as follows.

The 'mono' is not the intended use case. The results of 'mono' don't correlate well with stereo listening. On one hand this is the motivation of 'mono'--we see things that we won't see in 'stereo'. One might argue conversely, that the latter marks the results of 'mono' irrelevant. The concept is analytically sound but dosn't apply to the problem to be solved. (Better find a method that reveals quality paremeters when listening 'stereo'.)

The 'mono' is taken from commercial (synthetic) recordings, that are not designed to be listened to in 'mono'. This may have side effects, that are not understood. To my knowledge no investigations, neither theoretically, nor practically are undertaken to fill the gap. (Better let a sound engineer design a set of real mono recordings for this purpose, could be environmental sounds, music, speech--need to be.) The method relies heavily on the test panel knowing what a "good HiFi sound" could and should be; and there is more to it in regard to preference.

The essence of the method is the comparison of many speakers in 'mono', not just listening to one speaker alone. Additionally the audition is, of course, to be made without visual interference aka "blind". This is not available for amateurs. Hence the method cannot be replicated by the general public on a regular basis. To tell that 'mono' would be more revealing than 'stereo' even if a single speaker is evaluated alone is not supported by 'the science'.

You may see me as an 'anti' now. I'm decidedly not! I appreciate the standard that Harman introduced, even if it was commanded somehow. It was overdue for *decades*! I forgive nearly all the sloppyness in the process. But, when directly asked like in this thread, I would still be so honest to tell, mildly.

I issued my caveats many times now. No halfway sensible response, what does that tell? I'm not the engineer, and I'm happy with that.

 

[mwmkravchenko]

Yes. And in my experience, many classical music recordings have out-of-phase information that is essential to approximate realism. This is not studio panning, this is what is coming directly into the mikes, especially with minimally-miked recordings like those done by Telarc.

As a test signal, I like to use out-of-phase pink noise. I think this is a far more revealng test of speaker directivity + room interaction (and especially how that changes with frequency) than any mono test. (And recall that Harman research has shown that, in mono, pink noise is the most revealing of all test signals.)

Interestingly (to me, anyway), I have found that narrow directivity speakers tend to have subjectively wider projection (beyond the speaker boundaries) of pink noise than do wide directivity speakers. My hypothesis is that this is because the out-of-phase signal is being less contaminated by reflections.

On the other hand, for orchestral music, wide directivity speakers usually sound more realistic to me. Here my guess is that the room reflections are simulating the hall, in a way that is not true to the original recording, but is still subjectively more realistic to me.

I have quite a few Telarc recordings. What I can tell you is that they have no discernible soundstage. IN fact I have a friend that ran the Soundstream recorder for the early Telarc recordings and was a recording engineer himself. He tried to point that out, and the manner in which to correct the issue. Nothing changed. So you have interesting dynamics, but no real soundstage in any of the Telarc recordings. If you want the best example of dual mic stereo recordings search out Dorian recordings. They did 2 mic recordings well. And there are other classical labels that do a hybrid of 2 mic pickup with spot mono micing. Alpha is one that readily comes to mind. I'll add Reference recordings.

Mark

 

[Duke]

This is a 'might be' reiterated, but I would expect the correlation explained as a chain of causation.

Let me put it this way:

Is there a portion of the frequency spectrum where the ear is particularly sensitive to frequency response anomalies?

Maybe yes and maybe no. But IF SO, how might we identify which portion of the spectrum this is?

I think it MIGHT be that portion of the spectrum where the perception of loudness is the greatest for a given measured sound pressure level. (At the opposite extreme, I think our sensitivity to frequency response anomalies fades into nothingness in frequency regions where the SPL is below our detection threshold.)

If you have a better idea for how to identify the portion of the spectrum where the ear is likely most sensitive to frequency response anomalies, what is it?

And a new topic in the same pattern. I'm lost, don't kown what it is all about.

The sentence which followed what you quoted reveals why I thought the findings of David Griesinger and Earl Geddes are relevant to the topic of the frequency region from 1 kHz to about 4 kHz being particularly critical, which is the topic of the brief conversation I was having with @Salt and @Thomas_A.

Here is that sentence: "So perhaps there is room for some consensus on the frequency regions that are most critical, even if the reasons why are disputed."

What makes a speaker 'good' as a most general quest?

If you actually want me to respond to this I will do so, but first I have to ask: Is this just a rhetorical question?

 

[Heinrich]

Let me put it this way:

Is there a portion of the frequency spectrum where the ear is particularly sensitive to frequency response anomalies?

Maybe yes and maybe no. But IF SO, how might we identify which portion of the spectrum this is?

Sorry Duke, I had to revoke my initial reply. English too bad, not to the point.
To ask for "sensitive to frequency response anomalies" --well, the bass maybe. The individuals sensation is quite disproportional to the physical stimulus. But that was said before. In the upper registers I don't know. To conclude such sensitivity from the loudness contour alone won't help. The hearing is too complex for such a shot.

Not to forget, "sensitivities" are many. HD, intermodulation, tremolo, masking etc all have their own.

 

[MarkS]

I have quite a few Telarc recordings. What I can tell you is that they have no discernible soundstage.

To me, Telarc's orchestral recordings sound very much closer to what I hear at a live orchestral concert (from a mid-hall seat) than do most others, and that it what matters to me.

 

[Torin Krell]

The Telarc recordings used minimal miking techniques employing omnidirectional mics (usually just 3) and are therefore usually more phase coherent than the more common multi-microphone recordings. The omni mics used also had a very broad frequency response which helped provide the low end that most Telarc recordings are known for. The result, as described above, is a very natural sound but without a clear pinpoint like soundstage.

 

[MarkS]

Well, I don't hear "a clear pinpoint like soundstage" at the many live classical performances that I attend regularly, so that's not an issue as far as I'm concerned.

 

[mwmkravchenko]

The Telarc recordings used minimal miking techniques employing omnidirectional mics (usually just 3) and are therefore usually more phase coherent than the more common multi-microphone recordings. The omni mics used also had a very broad frequency response which helped provide the low end that most Telarc recordings are known for. The result, as described above, is a very natural sound but without a clear pinpoint like soundstage.

It's the spacing of the mics that allows the illusion of a soundstage or not. I agree that out in the audience there is no ability to pinpoint anything. But at the ideal position, where a mic setup is located it is. I take interest in all the layers. I started out in the back. French Horn. Learned to make loudspeaker enclosures and then drivers. The little things are what interests e as much as the large ones.

The goal of a recording is for the purchaser to enjoy the recording. If that is accomplished, then job done.

Mark

 

[MarkS]

I agree that out in the audience there is no ability to pinpoint anything. But at the ideal position, where a mic setup is located it is.

IMO, it's not "ideal" if it's not reproducing (as closely as possible) what I would hear as an audience member at a live concert.

I understand that other people have different goals.

 

[Newman]

IMO, it's not "ideal" if it's not reproducing (as closely as possible) what I would hear as an audience member at a live concert.

I understand that other people have different goals.

In that case, multichannel playback is a non-negotiable. [edit: What are you using?]

 

[bmc0]

In that case, multichannel playback is a non-negotiable.

In my experience, 2-channel works fairly well... if I never turn my head.
Multichannel is still better even with my head "in a vise" (so to speak), but head movement makes the improvement in spatial quality more obvious.

 

[Newman]

In my experience, 2-channel works fairly well... if I never turn my head.
Multichannel is still better even with my head "in a vise" (so to speak), but head movement makes the improvement in spatial quality more obvious.

I was talking about the science of human perception in a small home playback environment, as per a stated goal of "reproducing (as closely as possible) what I would hear as an audience member at a live concert". Not so much what "works fairly well" per isolated individual opinions during sighted listening at home, after adaptation, etc.

If the goal is as stated, then multichannel is non-negotiable. I recall that Mark was using 2-channel last year, and is still prone to describing users of multichannel for music in the third person, so I drew on science to provide him some advice in service of his own stated goal.

cheers

 

[MarkS]

In that case, multichannel playback is a non-negotiable. [edit: What are you using?]

There are basically zero dedicated multichannel classical recordings that were produced by engineers as more than an afterthought, and upmixing is necessarily a completely artificial process that I have no interest in. Plus the added expense and complication and getting the multichannels to work with the room.

My current system is in my signature.

 

[kyuu]

There are basically zero dedicated multichannel classical recordings that were produced by engineers as more than an afterthought

Seems a weird position, given the rather large number of multichannel classical recordings. Every single one was just an "afterthought"?

 

[sfogg]

and upmixing is necessarily a completely artificial process that I have no interest in. Plus the added expense and complication and getting the multichannels to work with the room.

My current system is in my signature.

All reproduced music is, by its very nature, artificial. Surround processing/upmixing varies greatly, some isn't great with music, some was literally built based on research into concert hall acoustics, classical music and the psychoacoustics of human perception of concert hall sound and some literally decompose the music to isolate original direct sound, early reflections and reverb and then move those to the proper locations.

 

[Kal Rubinson]

There are basically zero dedicated multichannel classical recordings that were produced by engineers as more than an afterthought,

Most of the recordists I know are dedicated to multichannel and have produced a large catalog of excellent classical recordings without any upmxing.

 

[bmc0]

I was talking about the science of human perception in a small home playback environment, as per a stated goal of "reproducing (as closely as possible) what I would hear as an audience member at a live concert". Not so much what "works fairly well" per isolated individual opinions during sighted listening at home, after adaptation, etc.

I was not defending 2-channel reproduction, but rather pointing out a particular failing of it (which, I think, is supported by evidence). Head movement is an important part of localization—especially front/back discrimination at lower frequencies where spectral cues don't work—and people often subconsciously turn their head to take advantage of this. Some people, however, tend to keep their head locked forward when engaged in "serious listening"; I speculate that this may be a learned behavior to avoid spoiling the illusion with 2-channel speaker setups and/or headphones (without HRTFs and head tracking, that is). As you know, the soundfield produced by only two speakers in a small room is not a very good approximation of what you get in a concert hall and head movement makes the error more obvious.

upmixing is necessarily a completely artificial process

Technically yes, but so is attempting to reproduce a complex soundfield using only two speakers.

 

[MarkS]

Most of the recordists I know are dedicated to multichannel and have produced a large catalog of excellent classical recordings without any upmxing.

Interesting.

Do you have recommended mutlichannel recordings of Beethoven 9, Beethoven 7, Ives 2, Stravinsky Firebird (complete ballet), Stravinsky Rite, Copland Fanfare, Copland Rodeo, Copland Appalachian Spring, Mussorgsky Pictures, Mozart 39 (with original instruments and tuning)?

These are my favorites and my go-to pieces for evaluating a sound system.

That's just for a start. I could easily list another 100 or so that I would want.

And I'm also pretty picky about performance: for example, most Beethoven is not played at the correct (Beethoven specified) tempi (although the situation is much better now than it was in the era of the imperial conductor).

And then there is the issue of particular performers for concerti ...

 

[Kal Rubinson]

I've published more than a 100 recommendations in my MITR articles and many more in my reviews. I have my favorites among the couple of thousand that I have on file but I am not going to sit down and select to your specific requirements. There are a lot to choose from.

What I will do is ask you not to say there is no modern MCH recording that compares with a given classic performance of the 20th Century. That's a cop out. Compare them with contemporaneous stereo-only recordings and you will find many winners.