Why evaluating the sound of a single speaker is essential

[RexrothPigeon]

@Satanica - Some thoughts:

1. You suspect that there is a (large?) number of speakers that are better off-axis
2. You suspect that the Harman studies, therefore, are flawed

If I'm characterizing your position accurately (please correct me if I'm off-base), then this is where we stand:

If you organize and run studies of your own to test your hypotheses, I'm sure everyone here will be very interested and you might even add a major new wing to the edifice of audio preference knowledge. Until then, though, your suspicions are not nearly enough to for reasonable people to reject Harman's well-documented and credible empirical data.

 

[Satanica]

@Satanica - Some thoughts:

1. You suspect that there is a (large?) number of speakers that are better off-axis
2. You suspect that the Harman studies, therefore, are flawed

If I'm characterizing your position accurately (please correct me if I'm off-base), then this is where we stand:

If you organize and run studies of your own to test your hypotheses, I'm sure everyone here will be very interested and you might even add a major new wing to the edifice of audio preference knowledge. Until then, though, your suspicions are not nearly enough to for reasonable people to reject Harman's well-documented and credible empirical data.

Just because tests have been performed and they are flawed, does not necessarily warrant a reject of data, or at least some or most of it. If you read what I've previously written, I've not requested a data rejection.

I'm an extreme practicalist and a consumer. When I read spinorama information, I don't have to worry about the axis it was performed at.

But when I read a sighted on unsighted listening review of a product, I want that data/review to represent the best version of the product. I think it is objectively a fact this is not always on axis and quite commonly.

Something else to consider, do you percieve that the end products, the speakers that are setup in most homes and HiFi shows are on or off axis to the main listening position? I know what I perceive and it's not on axis.

 

[NTK]

That's why there is the concept of the listening window. When you look at a few typical well performing speakers, the on-axis FR and listening window FR closely follow each other (with the listening window generally smoother due to averaging).

 

[krabapple]

Thanks for the belittlement, but if you're going to insult me, you should know that it's Autumn in the southern hemisphere

That season, too, comes around every year.

 

[Satanica]

That, too, comes around every year.

And I'll presume this kind of non-informational commentary comes around seasonably as well.

EDIT: Or maybe not.

 

[krabapple]

Let me be clear, I'm not against single on axis testing of speakers. But I still believe that I've presented a case to consider the limitation of such test. Dr Toole has already admitted/mentioned in this thread that toeing a speaker out in room could be a way to "optimize" them. Therefore, in those instances, on axis would be considered non-optimized.

So would it be correct to say, your beef isn't with mono speaker preference testing per se, but with the way the single speaker is aimed?

Also: when a certain speaker is said to be more 'tonally neutral off axis', how far off-axis are we talking about? And are we talking about a speaker 1) whose manufacturer *expect* off-axis listening (e.g., in-wall speakers that cannot be aimed; any speaker whose instructions are to not toe-in) or 2) whose manufacturer instructs the consumer to listen on-axis (toed in), having designed the speaker for that, but in fact performs better off-axis?

(leaving aside the third category, manufacturers who hedge their bets and advise owners to 'try both and see which sounds better')

 

[RexrothPigeon]

Just because tests have been performed and they are flawed, does not necessarily warrant a reject of data, or at least some or most of it. If you read what I've previously written, I've not requested a data rejection.

I'm an extreme practicalist and a consumer. When I read spinorama information, I don't have to worry about the axis it was performed at.

But when I read a sighted on unsighted listening review of a product, I want that data/review to represent the best version of the product. I think it is objectively a fact this is not always on axis and quite commonly.

Something else to consider, do you percieve that the end products, the speakers that are setup in most homes and HiFi shows are on or off axis to the main listening position? I know what I perceive and it's not on axis.

Okay, so what outcome are you looking for? Honest question--I can't figure out what you're trying to accomplish other than sharing your suspicions (which you have now done)

 

[Satanica]

So would it be correct to say, your beef isn't with mono speaker preference testing per se, but with the way the single speaker is aimed?

Also: when a certain speaker is said to be more 'tonally neutral off axis', how far off-axis are we talking about? And are we talking about a speaker 1) whose manufacturer *expect* off-axis listening (e.g., in-wall speakers that cannot be aimed; any speaker whose instructions are to not toe-in) or 2) whose manufacturer instructs the consumer to listen on-axis (toed in), having designed the speaker for that, but in fact performs better off-axis?

(leaving aside the third category, manufacturers who hedge their bets and advise owners to 'try both and see which sounds better')

I like. Well as mentioned previously, Erin will at least sometimes look at Spinorama and try to deduce an optimal angle. Of course, we can't assume he is absolutely correct absolutely all the time, but he tries. If a manufacturer insisted on a specific axis of reference, even if it appears non-optimal, then I presume he has or will oblige. I really hope I'm not misrepresenting him or getting him in the shit for this, but this general practice regardless of who does it.

Is/Was Harman blind stereo testing done on or off axis? All the photos I've seen it appears that the speakers are positioned straight forward, so off axis.

Practically speaking up to 30 degrees off axis for evaluation purposes, and just to be clear, I'm not referring to any mono single speaker testing here, that's all done on axis, period.

 

[Satanica]

Okay, so what outcome are you looking for? Honest question--I can't figure out what you're trying to accomplish other than sharing your suspicions (which you have now done)

That this thread be renamed to:

"Why evaluating the sound of a single speaker plus multiple speakers is essential"

Single < Single + Multiple

 

[RexrothPigeon]

That this thread be renamed to:

"Why evaluating the sound of a single speaker plus multiple speakers is essential"

Single < Single + Multiple

o..k...good luck w that

 

[sigbergaudio]

I'm quite perplexed by your statement above that I've bolded. I thought we would all be in agreeance that differences in tonality can be and will likely be percieved as "better or worse". Can't it be quite simply assumed that at least some listeners will overall prefer either the 0 or 20 axis tonality above? I'm confused that we have got to the point where this is being questioned.

I said that very thing in the next sentence in the post you quoted.

 

[sigbergaudio]

That this thread be renamed to:

"Why evaluating the sound of a single speaker plus multiple speakers is essential"

Single < Single + Multiple

I'm inclined to agree. But it is not very clear that this is your point (or even why this is your point) from your discussion on off-axis listening. Listening on the reference axis is possible with a single speaker as well.

 

[MayI]

Can you produce hard facts that counter my view of the current on/off axis product landscape?

The Burden of proof is 100% on you and you haven't any.

Have you ever noticed that in wall speakers with identical Left, Center, Right usually all fire straight into a room? Therefore, at the main listening position one is hearing the Center on axis and the Left and Right off axis.

The mono tests weren't in walls. Have you noticed center channels point straight ahead? Which direction do you point your "off axis" designs?

Let me be clear, I'm not against single on axis testing of speakers.

Great. So if you'd like to know how corner cases test blind, by all means do so.

 

[Newman]

[to Buckchester] I don't know man, you're telling the story. But if you're referring to the following, then I think you should pay attention to the bit in bold. I've made the point before, the overall best listening axis for a particular user in a particular room can't be assumed to be a manufacturers spec which they seemingly most likely have not produced anyway. The objectively best measured axis, can't be assumed to be a manufacturers spec, that can only be determined from spinorama.

"In my many years of evaluating loudspeakers I have always respected the manufacturer's "reference axis" for both measurements and listening - mono or stereo. To do otherwise would be irresponsible. Over the years the vast majority of loudspeakers performed best on-axis, so in the absence of a stated reference axis, that was used. That said, most manufacturers don't specify a reference axis, or reveal any useful measurements, so either they don't know or don't care."

Hi Paul, personally I am not sure why you are focusing on the Toole sub-quote that you bolded above, and not the first sentence, to wit, "I have always respected the manufacturer's "reference axis" for both measurements and listening - mono or stereo."

cheers

 

[Floyd Toole]

I still sense a confusion of purpose in this discussion, at least when my name and the Harman tests come up.

Back in post 1043 I said:
"Yes, mostly because of a confusion of purpose. The double-blind, equal loudness multiple-loudspeaker evaluations were designed to maximize the detection of resonances, not to determine if the overall spectral balance flattered specific recordings - recordings do not have consistent spectral balance. Resonances are more easily heard in mono - discussed in Chapters 4 and 5. The elimination of resonances, results in smooth, flattish direct sound, and if directivity is also smoothly changing, high sound quality ratings. If such a spectral balance is not found to be enjoyable in a particular situation, it is then a challenge to decide what is responsible. Often a bass issue (30% of our overall sound quality rating) which is a small room acoustics problem that is often inadequately corrected. Excessive bass is easily confused with insufficient HF, and vice versa. As I have said, only trustworthy anechoic data will describe what the speaker is doing, and in-room measurements are needed to evaluate what the room is contributing. Spinoramas enable the variables to be sorted out and addressed."

All mono tests were comparisons of 3 or 4 loudspeakers designed to maximize the detection of resonances, the most audible problem in loudspeakers. Listeners rated the sound quality as if they were judging absolute "fidelity" to some conscious or subconscious criteria of what sounded best. However, because of the rapid randomized comparison method of the test, the unspoken question being asked of listeners was "what is the loudspeaker doing to the sound?". Positional substitution rendered the room a constant factor, and 30 s musical loops ensured that all loudspeakers were evaluated with the same monotonous test sounds. The dominant variable was the loudspeaker. Problems were quickly revealed, and as could be seen in measurements resonances were clearly the dominant problem. They were easily heard, and the highest rated loudspeakers exhibited the least evidence of resonances, which by definition corresponds to smooth flat frequency response in the sound which is perceptually dominant, the direct sound. It was quickly observed that the highest rated loudspeakers also had smooth off axis frequency responses. This has been true since the first tests I did in 1966.

The music was a variable, but only in the sense that not all music revealed all resonances, and certainly not all at the same time. Some music was much more revealing than others. Pink noise was the most revealing of all sounds. Solo voices and instruments were generally the least revealing - use these to demo flawed loudspeakers. Measurements reliably reveal all resonances, audible or not.

But, then comes the question that reviewers and consumers ask: how does the loudspeaker sound with recordings?. This is where the "reference axis" might matter. But, at this point we confront the "circle of confusion", because recordings are not standardized test signals. They were mixed and. mastered using loudspeakers in rooms that are not the same as yours or mine, not even considering how they might have been equalized or acoustically treated. There are no standards.

Differences in spectral balance inevitably occur and over the years playback electronics have included tone controls, occasional "tilt" controls and now user-accessible parametric equalization to compensate for these variations. Fussy listeners use them - they are not "fix and forget" controls. Fortunately, things today are far better than in years past - just listen to some of the old "classics" through modern, neutral, loudspeakers. Remixes have helped in some cases, but we learned to like them with flaws.

The discussion about which listening axis is most flattering to most recordings is academically interesting, perhaps, but in the real world a tweak of a tone control or simple EQ fixes many concerns - a different loudspeaker is not a requirement, so long as it is not burdened by resonances or gross frequency-dependent directivity problems.

Finally, humans adapt. We normalize, learn to ignore, some kinds of flaws in sounds we spend time with. Problems may be there, but we are not aware of them. This explains why so many flawed loudspeakers have been satisfying so many listeners for so long. The adaptation can be instantly broken if there is a comparison to a superior sound, which is what drove the scientific investigations, and the multiple-loudspeaker comparison method.

Overlayed on all of this are the soundstage and imaging illusions of stereo. Inevitably the room is involved and no two are alike, so debates arise. Again there are no standards and the principle determinant of these perceptual factors is the mix itself, not the playback apparatus.

Does this make sense? All these topics are elaborated on in the 4th edition of my book for those who might be interested. Learning to interpret spinorama curves is a huge asset in choosing a loudspeaker, and using it to its best advantage. In-room bass measurements and EQ complete the exercise. Relying on subjective opinions formed in the commonly available circumstances leads nowhere reliable - but it feeds forum discussions.

 

[ahofer]

Solo voices and instruments were generally the least revealing - use these to demo flawed loudspeakers.

The stuff of high-end audio auditions everywhere.

 

[Buckchester]

The stuff of high-end audio auditions everywhere.

And online “reviews”!

“Only the Wilson Chromostatic was capable of delivering the emotionality of her voice. Oh, like liquid plankton, only this speaker was capable of such magic.” (Until his next review, at least.)

 

[Soniclife]

The stuff of high-end audio auditions everywhere.

A good quote for a t-shirt when going to a hifi show.

 

[krabapple]

That this thread be renamed to:

"Why evaluating the sound of a single speaker plus multiple speakers is essential"

Single < Single + Multiple

But your beef is with axial versus nonaxial listening. Which is a distinct variable from single versus two speakers.

I like. Well as mentioned previously, Erin will at least sometimes look at Spinorama and try to deduce an optimal angle. Of course, we can't assume he is absolutely correct absolutely all the time, but he tries. If a manufacturer insisted on a specific axis of reference, even if it appears non-optimal, then I presume he has or will oblige. I really hope I'm not misrepresenting him or getting him in the shit for this, but this general practice regardless of who does it.

Erin isn't doing double blind comparative preference listening, is he?

Is/Was Harman blind stereo testing done on or off axis? All the photos I've seen it appears that the speakers are positioned straight forward, so off axis.

Dr. Toole has already answered this. They followed manufacturer's recommendation. If there was none, it was on-axis. Hence my three question to you before, which you kind of punted on.

Practically speaking up to 30 degrees off axis for evaluation purposes, and just to be clear,

aka the 'listening window'

I'm not referring to any mono single speaker testing here, that's all done on axis, period.

Huh?

'Mono' here meant 'single speaker'.
All Harman preference tests were done with a single speaker for reasons explained many many times. They used the manufacturer's recommended aiming if provided, or on-axis if not.
All Klippel measurements are done with a single speaker.

So what are you talking about?

Hi Paul, personally I am not sure why you are focusing on the Toole sub-quote that you bolded above, and not the first sentence, to wit, "I have always respected the manufacturer's "reference axis" for both measurements and listening - mono or stereo."

cheers

"Paul" who?

 

[john61ct]

Paul Newman obviously