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Should we (I) get into speaker testing & measurement

Should we get into proper speaker measurements?

  • Yes

    Votes: 247 76.5%
  • Yes, but do it later.

    Votes: 30 9.3%
  • No. Stay with Electronics.

    Votes: 46 14.2%

  • Total voters
    323

Wombat

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Omg, I think I have to unblock this dude. This situations looks like it is getting entertaining.

Well, get on board before the crudesayer takes up Amir's promise of an exit sTROLL.
 

BDWoody

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I'm not sure why @Audiocrusader feels it is necessary or productive to keep accusing people of having "handicapping mental walls", lacking "mental strength", and expressing how much he looks forward to boomers etc. to die and be replaced ("the only cure is new blood").

Because he is a troll...
 

Wombat

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Nothing like a troll 'on a roll'. :facepalm:
 

oivavoi

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You can get a lot of data depending on what options you pay for. My main interest though is in generating the so called "spin data" as standardized now in CEA-2034A standard. Here is a Revel F22e as measured such:

Harman%2BANSI-CEA-2034%2Bexample%2Bfrom%2B2018.jpg


The black curve is on-axis measurement. Note how it goes down to 40 Hz or so. The typical measurement you see in magazines like stereophile consists of two measurements pieced together. On that goes from say 100 Hz and goes to 20 kHz. And another that goes from 100 Hz down. The former is measured as you could. But then it is "gated" to truncate any room reflections. Doing so eliminates the resolution of the graph in low frequencies. So another measurement is made with a microphone close to the woofer for low frequencies. Problem with this method is that there is a amplification of sound due to speaker front surface artificially amplifying the amount bass energy there really is. Here is JA's measurement of F228Be showing this issue: https://www.stereophile.com/content/revel-performa-f228be-loudspeaker-measurements

View attachment 38051

I have circled the hump which as you can tell, does NOT exist in the proper measurements Klippel performs where it eliminates the reflection mathematically. It is then able to use the same measurement distance as for high frequencies, avoiding the hump in stereophile measurements.

With respect on-axis performance then, we have the full response from a few hertz to 20+ kHz allowing us to examine whether it is flat or not. The flatter it is, the more accurate the speaker. And the more accurate, the better listener preference is.

Next is the "listening window." Here, it is better look at a difference between it, and on-axis window as expressed in orange: the "Early Reflection DI." Here, we want a smooth curve with no dips and peaks and we have that with F228 speaker, telling us this speaker performs well in room with much less messing around with acoustic products and such. Its reflections will be similar to direct sound and thus, better fused into one by the brain.

In contrast to this very useful measurement, we have a bunch of ad-hoc measurement points in stereophile:

119Revelfig5.jpg


It is not easy to characterize these dips and peaks as easily as we can with the orange line. And at any rate, there is no study correlating them to listening preference.

If I get this system, I will do a much more extensive write-up than this brief.

This looks great. And the more I think about it, the more I would like to see this Klippel project come to fruition.
(apologies if the following points have already been covered in the last 10 pages of the thread, that I haven't read yet)

My suggestion is a gofundme campaign or something similar for this specific project, where the pledged money only gets released to @amirm once the required goal is met.

Concerning these spins and how to visualize it: As for me I must admit that I find this slightly confusing. Is that only because I've become accustomed to the usual graphs for certain degrees off-axis? Perhaps! What I miss though, for my home use, is two things: How wide is the dispersion horizontally and vertically? This has bearings on the ideal placement and use. A speaker with more narrow dispersion - say, the Neumann KH80 - will probably work well even tucked away in a corner. A speaker with wider dispersion - say, the Philharmonic BMR bookshelf - may be the ideal choice if it's standing far away from side walls where a narrow dispersion speaker may sound sterile (plus that wide dispersion speakers usually seem to be liked by listeners in general). I struggle to retrieve this information from the graphs I see here.

Also, I do think it's useful to separate the "early reflections" thing into both horizontal and vertical reflections - again due to placement. A bookshelf speaker with very bad vertical directivity may sound bad placed on a desk, but may sound ok standing on a stand away from boundaries. Etc.

Otherwise: Go go go!
 
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Wombat

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FrantzM

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Hi


We are living some interesting times. Knowledge is available at an unprecedented level. We are literally submerged by information, to an overwhelming extent. It has become easier because of this glut, for mere mortals at home, to dabble in things that were up to now the province of multi-million (dollars or Euro or whatever strong currency one wants to use) facilities... e.g. biology. Bio-hacking is serious and scary... oops!Sorry about that O.T. ... It was to to make the point that today, it is much easier, with the help of technology and knowledge, real practiced, nurtured and cultivated by constant research and learning, to test loudspeaker in ways that makes sense to the enthusiasts willing to, at least, study some part.

What makes a teacher or researcher great/useful , is how she/he/they distill the hard science or technology to its essence and make it available to an interested. less educated or even less intelligent public. It is often too easy for many technologists or Scientists to smack you with equations that, while verified true. are only comprehensible by 100 persons on the planet... e.g. of such talks: "The eigenvalues of the Boolean matrix do not fully resolve this equation, better project it on a Riemannien space and solve the now, easier to understand Lagrangian transforms due to the Laplacien convolutions" ... WTF.. ?? Nooo ... the best teachers tell you that by using 3 subs you get a flatter, smoother in room response .. in the bass ... They quickly add that it is steady state in the bass ... No it isn't 1 + 1 = 2 .. You have to research it a bit but you get the point... In the bass you use a few subs , EQ them and you have the kind of bass you have up to then, been dreaming of and heard once or twice in a system ... or most often live. Believe you me the math behind multi subs is not trivial .... but it comes to that...
Well having digressed sooo much. This is what Amir and others are attempting and in some ways have performed here at ASR... Eminent contributors such as JJ., Floyd Toole, Don H56, SIY, SolderDude, Restorer John, Blumlein 88, Ray Dunzl , etc ... too many whose names I have forgotten ( apologies people, I will add these as I remember... ), have brought the hard Science and technology to mere enthusiasts in an unprecedented way.. unique among Audio websites. There were promises of such at WBF, it devolved... I would not slight DIYAudio.com, the level of knowledge of some contributors there is off the chart; the S/N ratio is much better here at ASR, however ...
Now we have a unique opportunity to see how we can in a crowd-encouraged (will explain this term later :D) way, test loudspeakers and find what makes them good or bad or just OK... This would be a breakthrough. Speakers, are the last frontier, now that a $9 dongle is audibly transparent, . Speaker are what makes or break a system. Logistics is always present although most people don't think about of it in their lives or businesses. How does one evaluate 4 different speakers pairs in one's home? .. You must bring them to your home. Try to do that with 4 pairs of speakers weighing 75 lbs each .... place these in the room, level match and compare ... by the time you are done, about 3 months later, working entire week-ends, you are too tired to care. The fun is out of the window ... along with spouse, children and friends ... you then use subjective rationalization, for a purchase so that you can finally go back to listening to music...


This ASR speaker project must be done. We must understand that it will be a work in progress. Amir and others will learn from it, will learn on the job. Discussions will enrich our knowledge. Enthusiasts will then be able to buy speakers on data or try their best to.. No longer will they need to listen to decide. This is what most have to do. Speaking for myself: I am on a search for an endgame system. Electronics is easy: Any DAC with a SINAD in the ASR Green Zone is good enough... Amplifier? Anything that performs as well, better or close to an NC1200 Hypex module. Source? Any laptop that can run Roon and Foobar. EQ/DSP, measurements? Same laptop with relatively inexpensive software some free. + UMik1 (<$100) + a tripod :p .... Speakers? SPEAKERS !!!???!! Oh! Boy!!!o_O

I for one, am immensely interested by this project. How is this to be done? I frankly don’t know. The impact on the person bringing this to life should not be underestimated but I repeat: The ASR Speaker project must be undertaken. My pledge remains. I’ll discuss it in PM with the King.

Seriously it is one of the most important projects in HiFi. Let’s try to crowd-think it. Crowd-encourage it.

Peace.
 
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echopraxia

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This looks great. And the more I think about it, the more I would like to see this Klippel project come to fruition.
(apologies if the following points have already been covered in the last 10 pages of the thread, that I haven't read yet)

My suggestion is a gofundme campaign or something similar for this specific project, where the pledged money only gets released to @amirm once the required goal is met.

Concerning these spins and how to visualize it: As for me I must admit that I find this slightly confusing. Is that only because I've become accustomed to the usual graphs for certain degrees off-axis? Perhaps! What I miss though, for my home use, is two things: How wide is the dispersion horizontally and vertically? This has bearings on the ideal placement and use. A speaker with more narrow dispersion - say, the Neumann KH80 - will probably work well even tucked away in a corner. A speaker with wider dispersion - say, the Philharmonic BMR bookshelf - may be the ideal choice if it's standing far away from side walls where a narrow dispersion speaker may sound sterile (plus that wide dispersion speakers usually seem to be liked by listeners in general). I struggle to retrieve this information from the graphs I see here.

Also, I do think it's useful to separate the "early reflections" thing into both horizontal and vertical reflections - again due to placement. A bookshelf speaker with very bad vertical directivity may sound bad placed on a desk, but may sound ok standing on a stand away from boundaries. Etc.

Otherwise: Go go go!

I agree about a specific campaign — and I‘d definitely donate again to a gofundme campaign on this topic specifically!

I also tend to agree with you on the measurements. Would this system generate a dense field of frequency response measurements at many angles, or does it ONLY generate spinorama measurements? I am hoping it’s the former.

Because I also find that how broad dispersion is even as it extends into upper treble matters quite a lot, or at least that’s my current hypothesis for why the Ascend Sierra 2 EX (exceptionally wide and smooth dispersion throughout the entire frequency spectrum up to 20khz) won so definitively against the KEF R3 in my blind test. I have a Neumann KH120 coming (whose measurements look to be near perfection, aside from the narrower dispersion) to compare as well, and this time I hope to do so even more rigorously.

Anyway, independent of how we interpret the graphs, so long as measurements do capture things like polar frequency responses off axis through horizontal and vertical spins, we should have all the data we need.
 

aarons915

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Concerning these spins and how to visualize it: As for me I must admit that I find this slightly confusing. Is that only because I've become accustomed to the usual graphs for certain degrees off-axis? Perhaps! What I miss though, for my home use, is two things: How wide is the dispersion horizontally and vertically? This has bearings on the ideal placement and use. A speaker with more narrow dispersion - say, the Neumann KH80 - will probably work well even tucked away in a corner. A speaker with wider dispersion - say, the Philharmonic BMR bookshelf - may be the ideal choice if it's standing far away from side walls where a narrow dispersion speaker may sound sterile (plus that wide dispersion speakers usually seem to be liked by listeners in general). I struggle to retrieve this information from the graphs I see here.

Also, I do think it's useful to separate the "early reflections" thing into both horizontal and vertical reflections - again due to placement. A bookshelf speaker with very bad vertical directivity may sound bad placed on a desk, but may sound ok standing on a stand away from boundaries. Etc.

Otherwise: Go go go!

Once you get used to reading them, you'll never go back. The early reflections have been shown to be the most important sound we hear after the direct sound, many of the various off-axis curves may look good or bad but may not matter as much to what influences what we hear. You can still tell how wide the dispersion is by how close to early reflections curve is to the listening window, which is also how the directivity index is calculated, so the closer to 0 that is, the wider the dispersion. The BMR Spin in Audioholics shows that well, it's the widest dispersion speaker I've seen. I agree it is handy to have a separate graph of the early reflections like Burchardt shows but with also including the overall ER curve in the main Spin, they have it omitted in theirs for some reason.
 

echopraxia

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I for one, am immensely interested by this project. How is this to be done? I frankly don’t know. The impact on the person bringing this to life should not be underestimated but I repeat: The ASR Speaker project must be undertaken. My pledge remains. I’ll discuss it in PM with the King.

Seriously it is one of the most important projects in HiFi. Let’s try to crowd-think it. Crowd-encourage it.

Peace.

I agree 100% that an "ASR Speaker Project" would be the most important project in HiFi audio today -- perhaps even in all of audio speaker review history! Especially so, if (as you describe) high quality technical plots are combined with easy-to-understand explanations, as we've come to appreciate from this site :)

I would be totally lost as to what DAC + headphone amplifier / preamp to buy, if not for this site. There are so many options out there, and so many severely under-performing products. Who knows how long it would have taken for me to find a top-notch product -- if I ever did at all -- without this site! There's almost no way I would have known on my own to check out Topping or SMSL or JDS Labs, etc. This is why I like to emphasize how profoundly helpful a similarly rigorous measurements-oriented review project would be for speakers.

To illustrate this even more so, take for example the blind test of KEF R3 vs Ascend Sierra 2EX I did: It's come to my attention that there is some debate whether the KEF R3's spin measurements from their whitepaper is accurate, since other independent tests showed significantly worse performance. This could explain why the 2EX lost, rather than the differences in tweeter directivity in upper treble which is the other running theory. In addition to this, often these measurements are plotted differently, use different smoothing parameters, sometimes slightly different definitions of each plot, etc.

But the problem is, we do not have the data to know! We can't know if the R3 lost due to KEF's published measurements being inaccurate or somehow biased, or if it lost due to the much narrower treble dispersion pattern, or something else.

The only way we can eliminate these confounding variables is by gathering measurements of these speakers that are (1) methodologically consistent, and (2) trustworthy as being neutral and unbiased.

I'm confident that an ASR Speaker project would accomplish both of these, in addition to the final touch of adding easy-to-understand layman explanations and interpretations in each review, as you mention.
 
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amirm

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I also tend to agree with you on the measurements. Would this system generate a dense field of frequency response measurements at many angles, or does it ONLY generate spinorama measurements? I am hoping it’s the former.
Assuming I buy every option, you will get both near-field and far-field measurements of entire 3-D space around the speaker. All of it can also be exported (again, through another expensive option) so that they can be further analyzed beyond the means of the program itself.

Here is an example of a laptop speaker where one is interested in near-field information:
1573234808944.png


But you can see by solving the wave equations, it is able to extrapolate response far beyond the measurement points. The near-field measurements significantly increase signal to noise ratio which enables one to measure indoors in domestic or work environment as opposed to anechoic chamber. It also reduces the effect of phase shift due to distance.
 

echopraxia

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This would be absolutely amazing data to have.
 

oivavoi

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Once you get used to reading them, you'll never go back. The early reflections have been shown to be the most important sound we hear after the direct sound, many of the various off-axis curves may look good or bad but may not matter as much to what influences what we hear. You can still tell how wide the dispersion is by how close to early reflections curve is to the listening window, which is also how the directivity index is calculated, so the closer to 0 that is, the wider the dispersion. The BMR Spin in Audioholics shows that well, it's the widest dispersion speaker I've seen. I agree it is handy to have a separate graph of the early reflections like Burchardt shows but with also including the overall ER curve in the main Spin, they have it omitted in theirs for some reason.

Point taken. I guess I'll need to get used to reading these plots, then.
 

echopraxia

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This equipment costs $70k, right?

Apologies if I'm repeating what's been said before, since I haven't yet read all the pages of this thread, but: I wonder how hard it would be to find ~70 members willing to each donate $1k to this cause (plus smaller donations from more people as well). I'd be happy to do so in the context of a crowdfunding-style campaign where I know if it succeeds, my $1k will be put to use to make this happen.

I'm probably being unrealistic though. But with different donation tiers and a broad enough crowdfunding campaign, who knows. The potential of an ASR Speaker Project just makes me very excited, especially when it would yield data like this :)
 
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amirm

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This equipment costs $70k, right?

Apologies if I'm repeating what's been said before, since I haven't yet read all the pages of this thread, but: I wonder how hard it would be to find ~70 members willing to each donate $1k to this cause (plus smaller donations from more people as well). I'd be happy to do so in the context of a crowdfunding-style campaign where I know if it succeeds, my $1k will be put to use to make this happen.

I'm probably being unrealistic though. But with different donation tiers and a broad enough crowdfunding campaign, who knows. The potential of an ASR Speaker Project just makes me very excited, especially when it would yield data like this :)
I very much appreciate the support. :) My original hope was that there would be a few very serious supporters which would put up say, $20K and I would then fund the rest. Alas, most of the votes for support where in $100 to $200 range meaning it would take many such people to make a dent in that.

The people who want to donate large amounts also talked about ownership in company, potentially wanting to set the direction of what gets tested, etc. which is not a direction I like to take. Don't need more bosses in my retirement days. :)

So my plan currently is to see how I can justify purchasing the unit outright myself, and then rely on goodwill of the membership to offset the cost afterward. It may not work of course and I could be in a hole for years. But it is the direction I am leaning on right now. Messages like yours give me hope that this could work.
 

oivavoi

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I very much appreciate the support. :) My original hope was that there would be a few very serious supporters which would put up say, $20K and I would then fund the rest. Alas, most of the votes for support where in $100 to $200 range meaning it would take many such people to make a dent in that.

The people who want to donate large amounts also talked about ownership in company, potentially wanting to set the direction of what gets tested, etc. which is not a direction I like to take. Don't need more bosses in my retirement days. :)

So my plan currently is to see how I can justify purchasing the unit outright myself, and then rely on goodwill of the membership to offset the cost afterward. It may not work of course and I could be in a hole for years. But it is the direction I am leaning on right now. Messages like yours give me hope that this could work.

But how about the idea of having a crowdfunding campaign, as I mentioned? Where the money only gets released to you once a certain threshold is reached? If you get that campaign going for a year or so, I'm very sure the goal could be reached. Such a campaign would also generate lots of interest in the project before starting. Speaking for myself, I would be willing to contribute quite a bit to such a campaign, particularly over a year, where it would be possible to donate smaller amounts several times, which is financially more easy for me. TBH I'm more hesitant to just donate money to the site in general, as I'm frankly not that interested in all the electronics measurements (you know I love you anyway @amirm, it's not you it's me ;) )
 
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amirm

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But how about the idea of having a crowdfunding campaign, as I mentioned?
I think it will sit there at a few thousand dollars and that would be that. I think people will donate more when they see the results.
 
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