Research Project: Infinity IL10 Speaker Review & Measurements

[Robbo99999]

There have been a ton of comments regarding the accuracy of the Klippel, or at least Amir‘s setup. Buchardt uses one and Amir’s measurements weren’t identical. Neumann‘s KH80 showed a valley in the bass in 2 models, so Neumann sent 1 model to Klippel themselves and their measurements don’t have that valley.

Even noted in this review, his mic setup causes some wiggles in the response, this was worse in earlier measurements, and it makes it look as if the speaker has resonances.

Ah, that's the whole thing then. It seems like a roundabout way of trying to come to a conclusion re Audiosciencereview Klippel accuracy by comparing current measurements of a 20 yr old speaker with tests done nearly 20yrs ago in an anechoic chamber which itself is not perfect (anechoic chambers)....I'm not sure how valid that comparison is, doesn't seem much can be learned that way, too many inconsistencies & inaccuracies I would hazard. Like mentioned in that other thread, testing the same speaker model and unit at the different "Klippel testing sites" (Klippel themselves / audiosciencereview) is praps the only way to be sure. Wouldn't it be easier to just choose a 'controversial' (or maybe even uncontroversial) speaker that Amir has access to and then send it themselves to Klippel for testing to see if it marries....that's simplest no?

EDIT: are you sure that this is the purpose of this review, doesn't make sense to me?

 

[QMuse]

You continue to be confused due to lack of real hands on experience with this topic. We absolutely want to rail against inexperienced people passing judgments on audio products in sighted tests. Speakers are included in that. I already explained this to you.

You can't mix that with trained listeners who get paid to do a job, not to provide online reviews for people. As I noted, they can make mistakes as I have explained about my own experiences. But in general, they provide reliable information. We had a handful of them at Microsoft and this is what they did all day, every day. Every few months we would conduct blind tests with larger scale but day to day development of products relied on trained opinion.

Look at the discrimination ability of Harman trained listeners:

They don't just lose that skill when you ask them to evaluate a speaker sighted. They continue to have powerful tools that you don't have. So you best listen to them.

Sure, you can have allowance of mistakes but to say that their opinion is worthless makes that statement worthless and no more.

Are we supposed to conclude from this graph that trained listeners are immune to sighted bias, like the one when you see distortion measurement and then magically you hear it and put blame on it for the speaker listening impressions? Is that on the y-axis scale?

I think you put the wrong chart in your response so let me help you with it. This chart is from http://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html , so the same you linked when you were preaching that only blind tests are valid.

And look at that - speakers were not even closely rated in blind test vs sighted test! That's a tricky one, isn't it?

Let's see what Olive said about it:

A Blind Versus Sighted Loudspeaker Experiment

This question was tested in 1994, shortly after I joined Harman International as Manager of Subjective Evaluation [1]. My mission was to introduce formalized, double-blind product testing at Harman. To my surprise, this mandate met rather strong opposition from some of the more entrenched marketing, sales and engineering staff who felt that, as trained audio professionals, they were immune from the influence of sighted biases. Unfortunately, at that time there were no published scientific studies in the audio literature to either support or refute their claims, so a listening experiment was designed to directly test this hypothesis. The details of this test are described in references 1 and 2.
A total of 40 Harman employees participated in these tests, giving preference ratings to four loudspeakers that covered a wide range of size and price. The test was conducted under both sighted and blind conditions using four different music selections.

In summary, the sighted and blind loudspeaker listening tests in this study produced significantly different sound quality ratings. The psychological biases in the sighted tests were sufficiently strong that listeners were largely unresponsive to real changes in sound quality caused by acoustical interactions between the loudspeaker, its position in the room, and the program material. In other words, if you want to obtain an accurate and reliable measure of how the audio product truly sounds, the listening test must be done blind.

Oh, I love this one so much I have to quote it one more time:

To my surprise, this mandate met rather strong opposition from some of the more entrenched marketing, sales and engineering staff who felt that, as trained audio professionals, they were immune from the influence of sighted biases.

Yep, I know, this one makes it really hard for you to talk your way out of it. I'm sure you are aware that reputation is easilly lost when you preach one thing in the morning and another in the evening so I'll just leave you to it.

 

[ROOSKIE]

I know some folks here are working the sighted test front.
I don't totally want to distract from that yet I can't help but want to figure out why the speaker sounded the way it did to Amir.
While I am very interested in unconscious bias and recognize it may(will) be at play here from time to time, lets assume it did sound exactly the way Amir described.
What could cause this? Everything I have read suggests that they way he described the sound could not have been due to the measured harmonic distortion in the speaker (however can't say no absolutely. )
What are the other options? Cabinet vibrations, dynamic compression, port leakage(rear ported though), port chuffing, old crossover components, the wave guide giving a cupped hands sound? What have we got?

 

[pozz]

I know some folks here are working the sighted test front.
I don't totally want to distract from that yet I can't help but want to figure out why the speaker sounded the way it did to Amir.
While I am very interested in unconscious bias and recognize it may(will) be at play here from time to time, lets assume it did sound exactly the way Amir described.
What could cause this? Everything I have read suggests that they way he described the sound could not have been due to the measured harmonic distortion in the speaker (however can't say no absolutely. )
What are the other options? Cabinet vibrations, dynamic compression, port leakage(rear ported though), port chuffing, old crossover components, the wave guide giving a cupped hands sound? What have we got?

All of that stuff shows up in the FR if it is significant. Really, if there is anything to consider it is the FR and sound power directivity curves.

Compare it:

To: https://www.audiosciencereview.com/forum/index.php?threads/genelec-8341a-sam™-studio-monitor-review.11652/

And: https://www.audiosciencereview.com/forum/index.php?threads/revel-m16-speaker-review.11884/

 

[pozz]

Are we supposed to conclude from this graph that trained listeners are immune to sighted bias, like the one when you see distortion measurement and then magically you hear it and put blame on it for the speaker listening impressions? Is that on the y-axis scale?

I think you put the wrong chart in your response so let me help you with it. This chart is from http://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html , so the same you linked when you were preaching that only blind tests are valid.

View attachment 70688

And look at that - speakers were not even closely rated in blind test vs sighted test! That's a tricky one, isn't it?

Let's see what Olive said about it:

A Blind Versus Sighted Loudspeaker Experiment

This question was tested in 1994, shortly after I joined Harman International as Manager of Subjective Evaluation [1]. My mission was to introduce formalized, double-blind product testing at Harman. To my surprise, this mandate met rather strong opposition from some of the more entrenched marketing, sales and engineering staff who felt that, as trained audio professionals, they were immune from the influence of sighted biases. Unfortunately, at that time there were no published scientific studies in the audio literature to either support or refute their claims, so a listening experiment was designed to directly test this hypothesis. The details of this test are described in references 1 and 2.
A total of 40 Harman employees participated in these tests, giving preference ratings to four loudspeakers that covered a wide range of size and price. The test was conducted under both sighted and blind conditions using four different music selections.

In summary, the sighted and blind loudspeaker listening tests in this study produced significantly different sound quality ratings. The psychological biases in the sighted tests were sufficiently strong that listeners were largely unresponsive to real changes in sound quality caused by acoustical interactions between the loudspeaker, its position in the room, and the program material. In other words, if you want to obtain an accurate and reliable measure of how the audio product truly sounds, the listening test must be done blind.

Oh, I love this one so much I have to quote it one more time:

To my surprise, this mandate met rather strong opposition from some of the more entrenched marketing, sales and engineering staff who felt that, as trained audio professionals, they were immune from the influence of sighted biases.

Yep, I know, this one makes it really hard for you to talk your way out of it. I'm sure you are aware that reputation is easilly lost when you preach one thing in the morning and another in the evening so I'll just leave you to it.

Is all this really necessary? The measured differences (see my post above) haven't even been fully discussed and the ad hominem is already flying.

 

[pozz]

All of that stuff shows up in the FR if it is significant. Really, if there is anything to consider it is the FR and sound power directivity curves.

Compare it:
View attachment 70695
To: https://www.audiosciencereview.com/forum/index.php?threads/genelec-8341a-sam™-studio-monitor-review.11652/
View attachment 70693
And: https://www.audiosciencereview.com/forum/index.php?threads/revel-m16-speaker-review.11884/
View attachment 70694

As a research project, is it possible with DIY means to deliberately construct speakers with specific sound power DI? @617 @Rick Sykora

 

[patate91]

I know some folks here are working the sighted test front.
I don't totally want to distract from that yet I can't help but want to figure out why the speaker sounded the way it did to Amir.
While I am very interested in unconscious bias and recognize it may(will) be at play here from time to time, lets assume it did sound exactly the way Amir described.
What could cause this? Everything I have read suggests that they way he described the sound could not have been due to the measured harmonic distortion in the speaker (however can't say no absolutely. )
What are the other options? Cabinet vibrations, dynamic compression, port leakage(rear ported though), port chuffing, old crossover components, the wave guide giving a cupped hands sound? What have we got?

As per Amir a year ago measurement won't show you what's the problem. You'll have to trust him.

....
While in electronics we have high trust in measurements, in acoustic domain, measurements can easily lie to you and lie big time. As wavelengths get smaller than the distance between your two ears, you cannot trust a single microphone measurements.
.....

 

[amirm]

As per Amir a year ago measurement won't show you what's the problem. You'll have to trust him.

You don't have to trust me. I just don't want to see dismissiveness out of hand because someone has read a quote here and there. Or has some other factor bothering him about me expressing an opinion.

Right now, none of you objecting have heard this speaker. You are at severe disadvantage in this discussion then. So use the information I am proving as the best proxy available until we get better way to extract this data.

While in electronics we have high trust in measurements, in acoustic domain, measurements can easily lie to you and lie big time. As wavelengths get smaller than the distance between your two ears, you cannot trust a single microphone measurements.

That is with respect to single measurement mic in a room. Here is Dr. Toole in his book:

 

[pozz]

1. Do you have an example of a speaker with an excellent spinorama that sound mediocre (with data) if running at a reasonable level for the speaker? Without data, this looks like BS to me.

2. Do you have a "be(ter) available estimator of preference"?

3. I agree we need more data and more experiments. Except convincing a University to run one, I do not see how we can progress on this.

Regarding #3. I think the main point of all this activity is that we do not need university-level resources. Using Amir's measuring gear and precise theorization we can narrow down the suspect parameters such that the differences can be understood in our own homes once we know which phenomena are at work.

Regarding blind testing. In our situation I think these are pretty much unnecessary. It's more important to correctly understand the theory and preceding work. The main thing Harman work established, as I see it, is to make measurements more meaningful than they were previously and the extremely labour-and resource-intensive setup of correct blind listening tests has been done. We have to 1) get a lot more measured samples of speakers, 2) isolate specific variables/significant differences and 3) only then see if we get repeatable results using just simple listening tests. That's the goal right? All this research should help us make decisions in really ordinary circumstances.

Amir already has a speaker he likes consistently, the Revel M17, and this odd one, the Infinity IL10. We just need a few more in between, at least one slightly worse, and another better, to understand.

Edit: What I want to point out is that we do not yet understand what slightly better or worse is between similar speakers, while the big differences in better or worse in measured results are fairly clear.

 

[GelbeMusik]

As a research project, is it possible with DIY means to deliberately construct speakers with specific sound power DI?

Even with less. I've told you before. I guess it was ignored, 'cause I guess only Toole / Olive are kind of scientific, right? I suffer from that rare disease myself, unfortunately. Well, that's punishment for curiosity. One's gruesome to hear distortion, others to science. Choose your poison.
If you toe-in the speakers, the DI will necessarily change. How and what is DIY, then. As You asked for.

 

[pozz]

Even with less. I've told you before. I guess it was ignored, 'cause I guess only Toole / Olive are kind of scientific, right? I suffer from that rare disease myself, unfortunately. Well, that's punishment for curiosity. One's gruesome to hear distortion, others to science. Choose your poison.
If you toe-in the speakers, the DI will necessarily change. How and what is DIY, then. As You asked for.

I'm talking Klippel measurements specifically. That level of precision is necessary.

 

[QMuse]

Is all this really necessary? The measured differences (see my post above) haven't even been fully discussed and the ad hominem is already flying.

Your post has nothing to do with the ongoing discussion, which is about blaming distortion which you have previously seen measured for a problematic speaker response and claiming one is immune to sighted bias because he's a a trianed listener. So certainly no ad hominem there.

As you can see distorion components are 35dB below signal so they cetrainly don't affect FR. Sure, as @ctrl showed they may be audible, but not in a way that they introduce "grunginess and lack of clarity to everything it played". Your claim that anything that is not seen in the FR response and directivity indexes is a well known claim by Toole that has been discussed here many times and is out of context of the ongoing discussion related to the Amir's claim that this speaker doesn't sound well because of THD. Toole would never support such claim, in fact he claimed totally the opposite saying that distorion rarely presents an audible isse with modern speakers. In fact, in his book you will find THD mentioned only on 2 pages saying exactly that.

 

[tuga]

Do you have any evidence that sighted test done by a trained listener applies to others? Btw, don't take it personal, I wouldn't trust Olive's sighted listening test done in your room after peeking at measurements. I simply don't believe in sighted test done by a single person. I treat it as personal opinion, not measured fact.

I am with @amirm here. He is not tasting for preference – that would definitely not apply to all listeners – but assessing how the speakers reproduce the signal, a bit like measuring with one's ears.

I don't know who are "we", but those 2 peaks simply cover to narrow frequency range to have impact you described in your listening test. Are you saying those 2 distorion speaks are indeed responsible for "grunginess and lack of clarity to everything it played"? Blaming THD measurement like this one for such effect is quite a bold claim..

I agree that it is possible Amir is attributing the wrong cause to the problems he's identified through listening.

 

[pozz]

Your post has nothing to do with the ongoing discussion, which is about blaming distorion which you have previously seen measured for a problematic speaker response and claiming one is immune to sighted bias because he's a a trianed listener. So certainly no ad hominem there.

View attachment 70700

As you can see distorion componenets are 35dB below signal so they cetrainly don't affect FR. Sure, as @ctrl showed they may be audible, but not in a way that they introduce "grunginess and lack of clarity to everything it played". Your claim that anthing that is not seen at the FR response and directivity indexes is a well know claim by Toole that has been discussed here many times and is out of context of the ongoing discussion related to the Amir's claim that this speaker doesn't sound well because of THD. Toole would never support such claim, in fact he claimed totally the opposite saying that distorion rarely presents an audible isse with modern speakers. In fact, in his book you will find THD mentioned only on 2 pages saying exactly that.

I've read the book. The assembled research proves that the distortion aspect is basically uninteresting although for perfectionism I'd like to see it reduced to as close to nothing as possible. That's certainly within manufacturers' reach.

Try as I might though, i could not like this speaker. Again, tonality was right but there is this grunginess and lack of clarity to everything it played. I tried to take the resonances out to fix it but at the end, it was not conclusive, nor did it make much of a difference. I even pulled my wife over to listen and she said there was some small difference with EQ but not enough for her to care.

I don't read anything specific to distortion here.

As I see it we have two prominent peaks, which if I remember right were counted as resonances by Olive/Toole, and uneven sound power as the main differences. All this discussion about Amir's hearing abilities is beside the point. Is your point to establish that his judgement is unsound and inconsistent? What's the use in that? Address the data and find more testing, not the person. By the way ad hominem doesn't mean "insults", it is an invalidation of an argument by calling attention to the person making it.

 

[napilopez]

What I like to do is get this speaker in other people's hands to evaluate. I am right now the only person who has measured and listened to these speakers. I like to broaden this pool. If there are any local people that are interested, let me know and I can loan them out and have you post your impressions here.

I've been waiting for one to show up here in NY for local pickup =]

I know some folks here are working the sighted test front.
I don't totally want to distract from that yet I can't help but want to figure out why the speaker sounded the way it did to Amir.
While I am very interested in unconscious bias and recognize it may(will) be at play here from time to time, lets assume it did sound exactly the way Amir described.
What could cause this? Everything I have read suggests that they way he described the sound could not have been due to the measured harmonic distortion in the speaker (however can't say no absolutely. )
What are the other options? Cabinet vibrations, dynamic compression, port leakage(rear ported though), port chuffing, old crossover components, the wave guide giving a cupped hands sound? What have we got?

It could be a combination of factors. Dynamic compression could be a good candidate too, perhaps transient response.

I also already posited earlier that the IL10 is recessed in the upper mids, as was evidenced by the multiple comments in Paper 1 attesting dullness and a midrange hole, which I, at least, associate with a lack of clarity.


Trouble is, by the looks of it, it may not be very different from the M16 in that regard. Perhaps in combination with other factors it could come off that way. Here's how the IL10 looks like vs the M16 with Amir's measurements (ER curve corrected with the proper formula):

However, this is complicated a bit by the fact that Amir's M16 measurement does show a midrange scoop while Harman's shows a more tonally balanced ER curve.

The M16 is an older measurement of Amir's though so it's possible there's something different about it, but it's interesting that it doesn't show the same close matching the Infinity IL10 did, despite that one being a much older speaker and tested far longer ago.


Nonetheless, the fact that the M16 and IL10 in the grand scheme of things measure fairly alike it interesting. I wonder if the M16's increased bass is shifting perception of tonal balance, and in combination with the relative lack of resonances and smoother frequency response curves gives it that edge.

Ah, that's the whole thing then. It seems like a roundabout way of trying to come to a conclusion re Audiosciencereview Klippel accuracy by comparing current measurements of a 20 yr old speaker with tests done nearly 20yrs ago in an anechoic chamber which itself is not perfect (anechoic chambers)....I'm not sure how valid that comparison is, doesn't seem much can be learned that way, too many inconsistencies & inaccuracies I would hazard. Like mentioned in that other thread, testing the same speaker model and unit at the different "Klippel testing sites" (Klippel themselves / audiosciencereview) is praps the only way to be sure. Wouldn't it be easier to just choose a 'controversial' (or maybe even uncontroversial) speaker that Amir has access to and then send it themselves to Klippel for testing to see if it marries....that's simplest no?

EDIT: are you sure that this is the purpose of this review, doesn't make sense to me?

In this particular case though, Amir's measurements of the IL10 are practically identical to Harmans, as shown in the last image above.

 

[tuga]

Looking at CSD graph I would also stick to what I said about the resonance at 1200Hz as it is visible at LW and PIR as well. Anyway, I have no trouble to believe that once EQ-ed this speaker would sound better but it is hard to say if it woul start to sound like M16 even if the preference score would be equal after EQ.

But that is not the point here - the thing seems to be Amir's opinion to blame THD measurement for the flaws he was hearing althoug Toole claimed THD is rarely an issue. I certainly find it hard to believe THD would be an issuse with the speaker ranked #1 in Olive's test.

The speaker ranked #1 in a particular sample of speakers. Are any of them any good?

 

[617]

As a research project, is it possible with DIY means to deliberately construct speakers with specific sound power DI? @617 @Rick Sykora

Within certain limitations, sure. The typical range of DI characteristics is typical because there tend to be a few configurations of drivers which sound good and are cost effective, and it is very hard to get directional bass and very hard to get Omni treble.

But yes, and that is my specific interest in speaker design. I am working on an effectively Omni speaker right now. Making an Omni speaker is easier than making something with narrow directivity down low, but that is where cardioid and dipole bass come in.

From a DI perspective, all box speakers are basically the same with only subtle differences. The good ones have smooth DI which tracks frequency response, and we have measured a bunch of good ones here. Wide or narrow intrinsic dispersion is a matter of taste although wide seems to be the preference.

It's worth remembering that DI only really affects sound in a certain passband. Below Schroeder, rooms will tend to dominate bass output regardless of whether it is monopole, dipole or cardioid. And at very high frequencies, the room will eat the output through absorbtion, making direct radiation the only percieved source.

 

[tuga]

Are we supposed to conclude from this graph that trained listeners are immune to sighted bias, like the one when you see distortion measurement and then magically you hear it and put blame on it for the speaker listening impressions? Is that on the y-axis scale?

I think you put the wrong chart in your response so let me help you with it. This chart is from http://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html , so the same you linked when you were preaching that only blind tests are valid.

View attachment 70688

And look at that - speakers were not even closely rated in blind test vs sighted test! That's a tricky one, isn't it?

Let's see what Olive said about it:

A Blind Versus Sighted Loudspeaker Experiment

This question was tested in 1994, shortly after I joined Harman International as Manager of Subjective Evaluation [1]. My mission was to introduce formalized, double-blind product testing at Harman. To my surprise, this mandate met rather strong opposition from some of the more entrenched marketing, sales and engineering staff who felt that, as trained audio professionals, they were immune from the influence of sighted biases. Unfortunately, at that time there were no published scientific studies in the audio literature to either support or refute their claims, so a listening experiment was designed to directly test this hypothesis. The details of this test are described in references 1 and 2.
A total of 40 Harman employees participated in these tests, giving preference ratings to four loudspeakers that covered a wide range of size and price. The test was conducted under both sighted and blind conditions using four different music selections.

In summary, the sighted and blind loudspeaker listening tests in this study produced significantly different sound quality ratings. The psychological biases in the sighted tests were sufficiently strong that listeners were largely unresponsive to real changes in sound quality caused by acoustical interactions between the loudspeaker, its position in the room, and the program material. In other words, if you want to obtain an accurate and reliable measure of how the audio product truly sounds, the listening test must be done blind.

Oh, I love this one so much I have to quote it one more time:

To my surprise, this mandate met rather strong opposition from some of the more entrenched marketing, sales and engineering staff who felt that, as trained audio professionals, they were immune from the influence of sighted biases.

Yep, I know, this one makes it really hard for you to talk your way out of it. I'm sure you are aware that reputation is easilly lost when you preach one thing in the morning and another in the evening so I'll just leave you to it.

There's a chance that the bias chart you posted only applies to blind AB testing Harman-style.

 

[amirm]

The M16 is an older measurement of Amir's though so it's possible there's something different about it, but it's interesting that it doesn't show the same close matching the Infinity IL10 did, despite that one being a much older speaker and tested far longer ago.

This is early in analysis but i received a Neumann KH80 and measured it. The results now don't show that slight dip that it did in the first two tries. The running hypothesis between Neumann and I are that temperature makes a difference. I measured M16 and KH80 during winter and it seems that may have impacted bass.

I need to test more but there just isn't enough time to keep up with huge amount of gear that has arrived let alone go back and redo tests.

 

[pozz]

Within certain limitations, sure. The typical range of DI characteristics is typical because there tend to be a few configurations of drivers which sound good and are cost effective, and it is very hard to get directional bass and very hard to get Omni treble.

But yes, and that is my specific interest in speaker design. I am working on an effectively Omni speaker right now. Making an Omni speaker is easier than making something with narrow directivity down low, but that is where cardioid and dipole bass come in.

From a DI perspective, all box speakers are basically the same with only subtle differences. The good ones have smooth DI which tracks frequency response, and we have measured a bunch of good ones here. Wide or narrow intrinsic dispersion is a matter of taste although wide seems to be the preference.

It's worth remembering that DI only really affects sound in a certain passband. Below Schroeder, rooms will tend to dominate bass output regardless of whether it is monopole, dipole or cardioid. And at very high frequencies, the room will eat the output through absorbtion, making direct radiation the only percieved source.

I'm curious if it's possible to create a number of very similar bookshelves that are largely the same in as many areas possible but with specific dips in DI, for ease of listening comparison, with slightly different baffle shapes, for example.