Ideas for more meaningful speaker measurements

[Rick Sykora]

Exactly! 5 years ago I looked at many of the graphs and measurements available with little or incomplete understanding of what I was looking at. It's only with time and self practice that many of these things start making any sense and you find ways to use available tools with repeatability and reliability. The discussions here on ASR (other places too) can quickly derail with speculation or alternative methods of achieving similar goals.

As for your OP, looks garish until you look at the scale (and understand its meaning) - if my speakers measured +/- 1dB I'd be quite happy.

No placebo for not putting in the work and learning. Not sure how to convey this or offer more meaningful dialogue about a DUT without the basic understanding of how equipment, speakers and rooms interact and how these graphs could potentially affect any of it.

I applaud your efforts though!

Thanks!

Feel free to share what was easier to comprehend and what was harder. IMO., there is too much variability to meaningfully consider the room without some major constraints. One exception might be something about distance/size. I think there is a lot of confusion over what speaker characteristics define one that can be used as a small studio monitor vs. one that needs to do justice to a large home theater.

Still looks to me as there is room to improve. A non-technical enthusiast should be able to look at the review and walk away with whether or not the speaker is a good candidate for them. Ideally, it should not take more than a simple webpage or video to get them up to speed. There are a number out there already, but they are often done by someone who knows way too much and does not know how to keep it simple. You cannot start with a set of design measurement and have an engineer explain. This is why the best docs come from technical writers who are often better equipped to translate technical detail.

 

[Rick Sykora]

The Internet is full of dumbed-down sources. Why should ASR be brought down to the level of 99% of the Internet? ASR and a very few other sites are worthwhile only because more advanced measurements and concepts often included.

Most of the world is STEM ignorant and very often STEM hostile. This fact is often demonstrated particularly on other forums where the discussion almost always turns to the Panthers instead of the measurements. This is because most all of the members of those forums don't understand even the basics of the ASR measurements such as a "dB" and how it is calculated.

If ASR is shooting for some sort of "ratings" by appealing to a wider audience with less technical content then it will lose what makes it worthwhile. There are already numerous audio forums with minimal technical content.

Am not sure ASR cannot handle all cases and pretty sure Amir's intent is not to limit ASR's reach either.

If we segment to consumers that are not enthusiasts, am pretty confident they are not seeking out ASR review content. So, would not endorse "dumbing-down". However, does not mean the user experience cannot be improved either.

 

[BoredErica]

As discussed briefly in private with Amir with regards to review of the speakers we build: They are designed to play with subwoofers, which means in isolation they have poor bass extension (by design). This will hurt their preference score. There's a perfectly valid explanation for this, but not necessarily immediately obvious for everyone. So there are a number of reasons things can look "off" while not necessarily being a problem. But also not necessarily easy to explain in all cases.

That's why I think score without sub is almost meaningless and there is score with subwoofer for that.

 

[Rick Sykora]

That's why I think score without sub is almost meaningless and there is score with subwoofer for that.

However, every now and then Amir measures a speaker that can function without a subwoofer.

Also, is futureproofing for times when he tests bigger speakers.

Have noticed that there is a distinct ASR divide between those who live where they can listen to subwoofers or bass heavy speakers and those who cannot. As am fond of saying, there is usually more than one good solution to a problem. Fortunately, Amir is able to deal with a bigger monitor speaker. Much beyond that is TBD.

 

[restorer-john]

However, every now and then he measures a speaker that can function without a subwoofer.

There's a huge number of audiophiles and an HiFi buyers who aren't remotely interested in subwoofers. Not sure how many subwoofers I have, probably a dozen or so and they just gather dust.

I took a B&W AS600 powered 10" subwoofer over to my father's place about a decade ago and he hasn't even plugged it in- not even once! I even offered him a matching pair of PSB 10" Class D subs I have lying around here unused, to put under his Yamaha NS-1000Ms. Nope, not interested.

I like listening to what speakers can do as they are designed, not how I think I can make them better with a powered boom-box subwoofer.

 

[Rick Sykora]

There's a huge number of audiophiles and an HiFi buyers who aren't remotely interested in subwoofers. Not sure how many subwoofers I have, probably a dozen or so and they just gather dust.

I took a B&W AS600 powered 10" subwoofer over to my father's place about a decade ago and he hasn't even plugged it in- not even once! I even offered him a matching pair of PSB 10" Class D subs I have lying around here unused, to put under his Yamaha NS-1000Ms. Nope, not interested.

I like listening to what speakers can do as they are designed, not how I think i can make them better with a powered boom-box subwoofer.

Lol, my father claims to have tin ears and so says he does not hear any differences…

I can do without a sub for most music listening. Only have them in my home theater. So, can hear the difference for some music. My wife is not a subwoofer fan and so even though don’t have to worry about neighbors, do try to keep her happy!

 

[JRS]

I'd like to hear the speakers. We have done this before on ASR, where 4 speakers of unknown brand were recorded playing snippets of sound. It was an interesting exercise. Another You Tube video shot in an audio dealership compared two high end loudspeakers of quite different proportions that was remarkable in that they sounded so much alike. In both these instances the recordings were made using affordable gear.

For me, the astonishing thing is that I felt like I was in the friggin room (I was using Sundara HP's w/ Oratory EQ) listening to some very capable speakers. I suspect the recording equipment was reasonably priced solid gear, and nothing extraordinary. Personally, I could even see a situation where I might buy say internet direct loudspeakers based on such an audition if I had access to verified Spin data.

If it were to become a standard, a suitably dimensioned and absorbent/reflectant listening room would have to be agreed on. In an ideal world we would all be equipped with Smyth Audio realizers with our own personal transfer function available for convolution..

 

[Rick Sykora]

I'd like to hear the speakers. We have done this before on ASR, where 4 speakers of unknown brand were recorded playing snippets of sound. It was an interesting exercise. Another You Tube video shot in an audio dealership compared two high end loudspeakers of quite different proportions that was remarkable in that they sounded so much alike. In both these instances the recordings were made using affordable gear.

For me, the astonishing thing is that I felt like I was in the friggin room (I was using Sundara HP's w/ Oratory EQ) listening to some very capable speakers. I suspect the recording equipment was reasonably priced solid gear, and nothing extraordinary. Personally, I could even see a situation where I might buy say internet direct loudspeakers based on such an audition if I had access to verified Spin data.

If it were to become a standard, a suitably dimensioned and absorbent/reflectant listening room would have to be agreed on.

Am a little skeptical about the value, but perhaps with the right conditions in place, might be useful.

 

[TimF]

Structural engineering tests, compression tests, torsion tests, shearing tests and that kind of thing over time settled on a general agreement about the effective and practical scale of analysis, and zeroed in subsequently on the most pertinent variables under the most pertinent conditions. Standardized tests and testing practices, rigorous testing practices, became not just the norm but the 'law' of the profession. Materials specialists and fabricators will have occasion to do very detailed analyses within a tight range of circumstances in assessing novel mixtures of components or novel applications. With relatively standardized products used in standard applications (such as woofers, midrange and tweeter speakers) used in residential audio across a specified band range of about 30 hz to 25khz, and within a narrow range of loudness/volume under residential uses, there simply shouldn't be a need to re-invent science or engineering, or to introduce philosophy of science considerations. I am wary that some folks fall easily into, or want to lead others into, the field of psycho acoustics; or they may hold onto the belief that they and talented others have exceptional hearing. Even if there are those with exceptional hearing, or exceptional olfactory, or exceptional sight, few manufacturers are going to design and build products to meet their demands. For most humans sound is received and perceived similarly, just as is taste and smell. In a way, socialization is a joint calibrating of perception. This is especially so for the vowel and consonant tones. Audio conveys content. How humans respond to content varies more between humans than how much variation there is between humans to perception of sound.

 

[JRS]

Am a little skeptical about the value, but perhaps with the right conditions in place, might be useful.

Hearing is believing. And believe me, I would of thought such a thing was sci-fi, until I heard it done. I have every confidence that colorations are audible under these conditions. I really wish I could find the link, but don't even remember who hosted or even the two brands--one was Revel. I don't use the word astonished lightly, and I been kicking up dust for a while.

Is it the same? Heavens no, but it is no worse than comparing cameras in a photography magazine.

 

[alex-z]

IMO, inter-modulation distortion needs to be weighed in more. Especially in the 2000-5000Hz region where our hearing is most sensitive.

You can build a 2 and 3 way design with similar preference scores, but the 3 way can produce significantly better IMD numbers by virtue of having proper diaphragm size and mass for each bandwidth. Maybe this is just me, but I find that causes a tangible improvement in tracks which have layered instruments and vocals.

 

[DWPress]

IMO., there is too much variability to meaningfully consider the room without some major constraints. One exception might be something about distance/size. I think there is a lot of confusion over what speaker characteristics define one that can be used as a small studio monitor vs. one that needs to do justice to a large home theater.

But in the end the room is everything along with the placement in that room, size, amount of natural or induced reflections/damping. If you look at the information presented in the Spin-O-Rama and understand it then you can deduce how that speaker might work in your space. Not sure there's a shortcut to self education.

Perhaps someone could come up with a web app that lets you punch in your room dimensions and characteristics with a XYZ speaker & LP placement that you could enter the Spin data into? Not without flaws but it might prevent high SPL needs folks from buying small monitors at the very least.

 

[Holmz]

One possible solution is to change the way things are presented, which may be a good idea. Another (not mutually exclusive) is to write and explain a bit more about what is important and what is less important.

And perhaps some real life examples (I guess both Erin and Amir have already been doing some of this in their videos) of what things actually mean, and the significance (or not) of different things.

It's also things that looks different between speakers without necessarily being a problem in either. So it's probably hard to make this completely transparent and understandable for everyone. It's not like anybody can just look at a directivity plot and go "Aha I understand exactly what I'm seeing".

I could be Sancho, if you find a person that like a Quixotic challenge.

 

[Blumlein 88]

IMO, inter-modulation distortion needs to be weighed in more. Especially in the 2000-5000Hz region where our hearing is most sensitive.

You can build a 2 and 3 way design with similar preference scores, but the 3 way can produce significantly better IMD numbers by virtue of having proper diaphragm size and mass for each bandwidth. Maybe this is just me, but I find that causes a tangible improvement in tracks which have layered instruments and vocals.

Do we need the 32 tone test for loudspeakers? Probably could get a few people to do one with REW at the LP just to get an idea how much the results of such vary.

 

[Wesayso]

Even though a Klippel is a very nice piece of equipment, it can only measure the speaker's performance. What do i mean by that? It measures how flat the frequency response is, we get a PIR, we get the DI, but what we don't get is what that does once we put it into our own homes.
Then there's the problem we have 2 ears we listen with, which means the left channel bleeds into our right ear and the right channel into our left ear.
While this may sound insignificant, it does cause dips and peaks in the frequency response we get at our listening position. Dips and peaks in a Stereo signal that fakes something (phantom center) that comes from right in front of us. If there was a sound source right in front of us, those dips and peaks wouldn't be there. A speaker that is uneven, right where those dips and peaks are, might actually sound quite convincing if those dips/peaks counter the cross talk effects somewhat, happening at the listener's ears. It might even be why some form of BBC dip still lives on while the actual reason for that dip was something different entirely (related to the speaker they were developing at the time). It has gained a new meaning for many and lived on as a tweak that can even have many meanings as to where that dip should be.
I know Floyd Toole mentioned that reflections will fill most of those (cross talk) dips quite well, but not without consequences. The timing of those reflections do matter, as it brings quite a different presentation if they are very early (<7ms) early (>7 ms <10) ms or late (> 10 ms or more). Most of the readers probably have not heard what those differences actually sound like. So how is one to know if they like a wide pattern or a more narrow pattern speaker. I guess (or hope) we can all agree that a smooth DI will help make a better speaker, but the pattern control needed is a lot more difficult without hearing the differences and knowing what it does in your room to/for your ears.
After following many discussions about this, where it is known that Toole advocates the beneficial nature of reflections while Dr. Earl Geddes tried to convince people we would have to avoid early reflections as much as possible, both of these theories might actually be (somewhat) right. Some consensus was found that those who like classical music tend to like a wide pattern more. Those who listen more to studio recordings like 'pop music' might prefer a more narrow pattern (or at least avoidance of early reflections (<10 ms).
Without knowing what one likes, the current reviews might not tell us enough. As it is the room's response to the chosen speaker within the room that determines a lot of how the sound and the presentation is going to be.
One cannot put a preference label on that as long as there's widely differing tastes and preferences out there. Aside from the previously discussed flaws in that system.

Just a few thoughts, after spending quite a long time trying to determine my own preferences.
(and finding ways to make use of the knowledge about cross talk and it's effects)
f.y.i. my preferences are avoiding/absorbing early reflections <15ms, while adding a Haas kicker at ~17ms.

Hope it fits within the discussion.

 

[Plcamp]

I think there is something within this recent blog by Joseph Crowe.

It appears to me his - I will call it ‘many tone’ distortion envelope detection when measuring drivers - creates an overall figure of merit for all distortion combined, and might address the common concern of IMD not being adequately covered. Notable that the figure of merit is independent of volume. Drivers with flat Bl vs displacement appear to differentiate.

Edit: The fact the compression driver example shown in the blog determines that the driver’s dynamic range is both volume independent and fixed (because the noise floor is tracking volume) makes me suspect this test really has detected the totality of distortion.

Distortion and Sound Quality --- What is Reasonable?

Introduction In this blog post I would like to discuss distortion levels in loudspeakers in the context of high end audio (HEA). What are reasonable levels of distortion and how do we measure it? Setting a target For the sake of discussion let us randomly select a target distortion level of...

josephcrowe.com

 

[DanielT]

Do not know if it has already been written but index how "smooth" the speakers are That is, how they go up and down in impedance. Whether they are amp current demanding monster speakers or not.If it is practically feasible. I do not know under what conditions this could be measured.

Edit:
For example, a person (not me) who is going to buy speakers for his tube amplifier. How could he (or she) be able to decide which speakers are good? Suitable. Sensitivity is stated, so is Ohm, but that, Ohm, is probably still only a nominal value. Or?

 

[storing]

Wonder how many would flock to buy this speaker now?

As others have mentioned, this an education problem: anyone interpreting that graph thinking "wow that's bad" without further thought is essentially doing it wrong. But I think this can actually be solved at least partly: anyone which is keen enough to learn and didn't yet realize that the 2 graphs you show are slightly different representations of the same measurement, will now have learned something from reading your post. So a sticky thread which contains this with a short explanation, and perhaps an explanation of how the raw measurement data (assuming that is included in all reviews, which is a must imo) can be smoothed etc, would be part of the solution perhaps, no?

You measure after you understand what the results will mean, not the other way round as you suggest.

Perhaps clarify what you mean exactly, because as it stands, to me this sentence reads like the opposite of science As in: in the fields I work in, it happens all the time results come in and no-one really knows what they mean. So I assume you mean something like 'if you measure you should also know how to interpret measurements' ?

 

[Digby]

The Internet is full of dumbed-down sources. Why should ASR be brought down to the level of 99% of the Internet? ASR and a very few other sites are worthwhile only because more advanced measurements and concepts often included.

Most of the world is STEM ignorant and very often STEM hostile. This fact is often demonstrated particularly on other forums where the discussion almost always turns to the Panthers instead of the measurements. This is because most all of the members of those forums don't understand even the basics of the ASR measurements such as a "dB" and how it is calculated.

Maybe a good start would be, and apologies if I have missed something like this, a post at the top of every sub forum here like "highly recommended reading, start here" or some such. I think there are reading recommendations, but they are scattered through different threads.

Obviously, most of this literature would have to be reasonably accessible to the layman and should start from the fundamentals. That would be useful to get the forum up to a base level of understanding.

 

[sarumbear]

Perhaps clarify what you mean exactly, because as it stands, to me this sentence reads like the opposite of science As in: in the fields I work in, it happens all the time results come in and no-one really knows what they mean. So I assume you mean something like 'if you measure you should also know how to interpret measurements' ?

Maybe this will help. Einstein understood the general relativity but he was unable to test it. He did though formulate it. Scientist that followed him used his formulas and finally proved it in tests.

In science, everything starts with a concept, followed by mathematical description then test to prove it. In engineering (and some sections of medicine) this may not be the case as scientists already gave us the formulas. We can start with the tests.