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What to make of the Audio Science Review of the Magnepan LRS ?

72.36.1.26

Are Amirm's measurement techniques simply bad or insufficient in this case ?

Or is the LRS speaker really as bad as Amirm says it is ?

Follow Ups:

RE: What to make of the Audio Science Review of the Magnepan LRS ? - trebejo 11:16:02 08/09/21 (0)
That website is toxically flawed.

Here is a link to a "review" that was just a silly hatchet job, obviously measured incorrectly, of an item that usually gets very good reviews,

https://www.audiosciencereview.com/forum/index.php?threads/marchand-xm44-analog-active-crossover-review.12026/

...and the kicker is that the obvious flaws in his results were pointed out repeatedly to him but the original mistake was never walked back. So the dude brags about how scientific he is, and then refuses to countenance obvious contradictions between his result and what just about anyone else observes.

So the place is flawed because he's flawed, and toxic because the false veneer of "scientific" confuses those that are not able to experience the equipment directly. Imagine people deciding that they have to have a line-level crossover, and being persuaded with pseudo-science to avoid one of the best sources for such equipment?!

Pseudo-science is quite toxic. Real science is a real ego-killer, but that dude's ego is not going down anytime soon...
RE: What to make of the Audio Science Review of the Magnepan LRS ? - triamp 02:27:16 03/30/21 (3)
I think measurements are important. Audio products are designed and built by engineers, and engineers use measurements. How could there be any form of QC at magnepan if they didn't measure how their products performed?
My MG 3.6's measure VERY WELL in my listening room from my listening position. And I think that is the key- Amirm used the Klippel robotic system which assumes a box speaker with sound only coming out the front, with the speaker expected to be a point source for the most part. There is no provision in this physical measurement scheme for dipole speakers that depend to some degree on the room for their sound quality.
Planar speakers generally assume listeners will be in a fairly specific location in relation to the speakers and the room. Placement is more important with Magneplanars than with most speakers because of the dependence on the room. I think if you listened in an anechoic chamber to an LRS it would sound just as crap as Amirm's measurements show. But listened to positioned properly in an actual room, the LRS sounds quite good. Amirm's fancy Klippel robot can't measure the LRS the way it is intended to be listened to. Instead of using that gizmo, he would have been better off to adjust the position of an LRS in a room until it sounded OK by ear, and then set up a regular measurement microphone at the listening position and do sine sweeps warble tones or whatever he prefers to make a graph of SPL vs Frequency. All the off-axis stuff captured by that Kippel robot which is then run through some fancy math just does NOT tell a coherent story about a dipole speaker.
I bet if he measured open baffles like Linkwitcz or Emerald designs his system would also be stymied. And, sadly, he doesn't seem to understand that there are speakers designed to a different paradigm than forward-firing boxes.

================================
Science doesn't care what you believe.

Edits: 03/30/21
- to be real! - farfetched 14:54:22 04/04/21 (0)
  Top flight reading of the situation.
  
  And by reading, I mean "reading" as it is used in the classic documentary, Paris Is Burning, by the late and stolen from us great, Venus Xtravaganza.
  
  Indulge me:
  
  Stymied by your paradigm again honey? The robot doesn't want to work for you? Well, listen to this, honey, I've got ears, and they're REAL, and so does our good friends at the maggie factory, and something else, engineers know how dipoles work but it is just too much for you, isn't it Armim? You just can't handle it. Your paradigm is is not up to it. Music is not a point source honey. It's a wave function, in a room, and you think oh, bad sound is not *my* problem, it's not maybe *my* issue?
  
  Please. Get real.
  
  / optimally proportioned triangles are our friends
- +1 (nt) - josh358 10:57:59 04/04/21 (0)
  .
- RE: What to make of the Audio Science Review of the Magnepan LRS ? - pictureguy 13:15:38 04/03/21 (0)
  It IS possible to, once a design is finalized and vetted, to make a bunch with only a 'function' check at the end of the line.
  The idea is to perform EACH operation in the fabrication of the speaker to Specification and Correctly.
  
  Operators DO measure at certain points in the manufacture. For example? Measure the DCR of the wire / ribbon after fabrication TO the substrate.
  
  Caps / inductors are already confirmed. You PAY your supplier for the right stuff of good quality, after all!
  
  Trained persons assemble the crossover boards THAN pass them to the person doing the install and wiring.
  
  After that, a SIMPLE and quick 'frequncy sweep' of each panel is all you need. And as confidence builds, you need only check every 5th than 10th panel.
  
  What I write is fairly in-line with modern quality practices. I may change my tune after an inspection, (not tour) of the plant and looking at quality records and practices / training.
  Too much is never enough
ASR - paul3 16:51:13 03/27/21 (1)
Audio Science Review. The best place online to waste your precious time if you love endless debates about how many micro-widgets will fit in a nanocube.
- RE: ASR - peppy m. 12:51:11 03/29/21 (0)
  Amir's measurements are sometimes useful, but his correlations are sometimes questionable.
Interesting that Amir's "subjective" listening test went as badly as his "objective" measuring test. - peppy m. 11:23:26 03/26/21 (4)
But even I know (as a former Maggie owner) that all, or at least most, big dipoles can be difficult to set up properly.
If you want to hear their best performance, you might not be able to simply plop your Maggies down in the same spot in the room where your old monopole speakers thrived and expect good sound. It might take only minutes to find setup success with a pair of Maggies...
BUT ( < notice the big "BUT" ), it might also take hours (or even days) before one finds the exact spot in the room where Maggies sound their best. One needs to be willing to invest the time needed, if need be...
But I suspect that Amir never bothered with the (sometimes) painstaking process of Maggie setup before he pronounced his bitter judgement against them. If he would not or could not be bothered, then he probably deserves to remain ignorant.

Edits: 03/26/21 03/26/21
- RE: Interesting that Amir's "subjective" listening test went as badly as his "objective" measuring test. - josh358 11:04:10 04/04/21 (0)
  What he did was listen to a *single* LRS, and complain that the image shifted with frequency!
  
  Well, of course it shifted, the speakers are made in symmetrical pairs. And Harman's research indicates that dipole speakers in general suffer when you don't listen in pairs. It ruins their imaging, after all, which along with transparency/absence of box resonances is their prime asset. You certainly aren't going to buy them for extended bass or 130 dB SPL's!
  
  And when I asked him how far it was from the wall, etc., he didn't reply.
  
  I wouldn't put too much stock in his listening.
  
  Amir and I did, though, have a more interesting discussion of planar imaging later on, after I'd gotten fed up with people evaluating the speaker without ever actually having listened to it and told them I wasn't going to respond to their posts.
- RE: Interesting that Amir's "subjective" listening test went as badly as his "objective" measuring test. - E-Stat 17:51:05 03/27/21 (0)
  If you want to hear their best performance, you might not be able to simply plop your Maggies down in the same spot in the room where your old monopole speakers thrived and expect good sound. It might take only minutes to find setup success with a pair of Maggies...
  
  This is exactly the argument I advanced to Sean Olive regarding the Harman speaker "shuffler" years ago.
  
  Note he had no response.
- RE: Interesting that Amir's "subjective" listening test went as badly as his "objective" measuring test. - sbrook 23:17:01 03/26/21 (1)
  Did he actually do a stereo listening test? I thought he only listened to one. That may or may not be a useful mechanism to evaluate a traditional monopole box speaker but not a dipole panel.
  - RE: Interesting that Amir's "subjective" listening test went as badly as his "objective" measuring test. - peppy m. 10:29:19 03/27/21 (0)
    Yes, it reads as if he did listen to only one speaker and that seems to me a strange way to listen to any speaker, not just dipoles.
Further illustrates - E-Stat 18:16:49 03/25/21 (3)
He doesn't know what he doesn't know. ;)

And who is the Asian chick wearing the lampshade?
- RE: Asian ***** in lampshade - peppy m. 09:01:45 03/26/21 (1)
  I believe she's (or, "he's" ?) a character in an Asian flick. I forget which one though.
  
  Edits: 03/26/21
  - Forget... - E-Stat 17:46:30 03/27/21 (0)
    whether "he" or "she" or which Asian chick flick? ;)
- RE: Further illustrates - Norman M 19:28:32 03/25/21 (0)
  "Chicks"?, that's a no no.
RE: What to make of the Audio Science Review of the Magnepan LRS ? - Joe Schmo 18:48:31 03/21/21 (3)
I believe it was Nelson Pass that said something like, the human ear is not a microphone and the brain is not a tape recorder. He among many others recognized early on that measured performance of certain specs (remember the Japanese mass market THD amplifier war of the '70s?) and subjective listening experiences were often poorly correlated.

Which also reminds me of the discussion here a few years ago of the hotly debated reluctance of Magnepan to allow Stereophile Magazine to do a full review of their products. Per their policy that would require measurements, and as I recall John Atkinson and Wendell Diller could not agree on the methodology involved in how that would be done.
-Joe

They're not that big!
- RE: What to make of the Audio Science Review of the Magnepan LRS ? - theaudiohiffle 18:17:44 03/24/21 (1)
  And just the past few years John Atkinson has admitted that he just doesn't know how to adequately measure planar-style speakers, and cautioned others against measuring badly. Nice to see somebody willing to admit they were wrong.
  Harry
  - RE: What to make of the Audio Science Review of the Magnepan LRS ? - josh358 11:09:56 04/04/21 (0)
    Yep. It's a challenging business. He makes pseudo-anechoic measurements close up, but *you can't do that with a dipole,* it shows ridiculously exaggerated bass.
    
    He also points out that when he measures impulse response, he doesn't know what consists of the actual speaker output and what consists of reflections. It's very hard to get a quasi-anechoic measurement of a line source dipole. You have to measure at the listening seat, not a meter from the speaker (which you should actually do with any speaker), and you have to keep room reflections out of the window by keeping the window and mic more than the speaker height away from walls. Even then -- if you window out the floor and ceiling reflections, you're going to get less bass than there actually is.
    
    I asked him why he didn't do in-room measurements and he said that it would be impractical.
- RE: What to make of the Audio Science Review of the Magnepan LRS ? - Davey 19:22:49 03/21/21 (0)
  Yep.
  
  I think it was probably the Stereophile 3.6 review twenty years ago that soured the water with Magnepan. The JA measurements in that instance clearly mischaracterized the nominal response the speaker would exhibit in a typical listening environment.
  
  Now here we are twenty years later and another set of "anechoic" objective measurements misses the mark regards floor contribution and various nearfield/farfield measurement issues.
  
  Ahem.
  
  Dave.
RE: What to make of the Audio Science Review of the Magnepan LRS ? - SteveJewels 07:59:01 03/21/21 (6)
Amir produces some interesting work. His analysis of the LRS's is not one one of them.
The sound propagation pattern of a point source is an expanding circle, a cone shape if you will. It reflects off the ceiling and floor as well as the walls, has no (useful, only destructive internal interference) rearward propagation. The SPL decays as the inverse square of the distance.
The sound propagation of a line source is radial about the vertical axis of the transducer and has no floor or ceiling reflection to speak of. The SPL decays linearly from the source. This does not even include dipole propagation.
Using measurement methods developed to quantify the performance of point source speakers to measure a line source, not to mention a dipole is ludicris. It is like using a ruler to measure liquid.
Daniel von Recklinghausen, the renowned audio engineer at EAD and KLH is famous for this old chestnut: "If it sounds good and measures bad, - you've measured the wrong thing."

Edits: 03/21/21 03/21/21 03/21/21
- agree: the assumptions of the inverse problem are probably not held - DrChaos 22:48:06 03/21/21 (0)
  It isn't an actual anechoic measurement. Those might be more interesting and applicable at higher frequencies if taken in a true physical anechoic chamber of sufficiently large size.
  But the system wasn't designed for systems which have emitters with spatial dimension substantially larger than a wavelength. It's based on a series approximation to the angular component of the acoustic propagation (Poisson's equation) in spherical coordinates.
  This is classic PDE separation of variables in spherical coordinates, and useful for spherically symmetric systems. I learned it in electromagnetism & quantum mechanics classes where you separate electrostatics & Schroedinger equation in spherical coordinates: there's a radial part and an angular part, "spherical harmonics".
  The system being used (Klippel) for the 'quasi anechoic' measurements uses that: it measures something in angle-azimuth space, and reconstructs---by fitting and ignoring higher order terms---an estimate of the response.
  The problem is such an inverse problem can be pretty unstable when the assumptions underlying the spherical symmetry aren't upheld and there's inevitable noise & inaccuracy in the raw measurements.
  It's probably pretty decent system for near field studio monitors, but not really for predicting perceived power field distribution of a dipole in far field in a real room, as people are likely to use the LRS.
  The only thing you can get from the review that's not really controversial (and I agree with) is that there isn't that much low bass. But that is hardly news and entirely expected.
  http://www.klippel.de/products/rd-system/modules/nfs-near-field-scanner.html
  - http://www.klippel.de/products/rd-system/modules/nfs-near-fi (Open in New Window)
  Edits: 03/21/21
- Just to clarify- for any practical-sized line source, there will be...- - MWE 08:27:02 03/21/21 (4)
  floor and ceiling reflections at the lowest frequencies (where the wavelengths are longer than the driver dimension), but little above.
  
  Mark in NC
  "The thought that life could be better is woven indelibly into our hearts and our brains" -Paul Simon
  
  Edits: 03/21/21
  - RE: Just to clarify- for any practical-sized line source, there will be...- - SteveJewels 08:55:01 03/21/21 (3)
    Please cite your source.
    - It's basic acoustic physics. Dispersion widens with... - MWE 10:27:11 03/21/21 (2)
      wavelengths larger than the transducer dimensions, and narrows with wavelengths smaller than the transducer dimensions. I could cite sources, but it's a very well-known principle.
      
      Mark in NC
      "The thought that life could be better is woven indelibly into our hearts and our brains" -Paul Simon
      - RE: It's basic acoustic physics. Dispersion widens with... - SteveJewels 17:53:10 03/21/21 (1)
        
        In Reply to: RE: It's basic acoustic physics. Dispersion widens with... posted by MWE on March 21, 2021 at 10:27:11
        
        "wavelengths larger than the transducer dimensions"
        
        I am not quite sure what you are saying there.
        
        "I could cite sources, but it's a very well-known principle."
        
        Please do. I have line source speakers. I know they are fantastic but I have much to learn about the physics.
        
        Instead of saying "larger wavelength", let's say... - MWE 18:37:33 03/21/21 (0)
        
        In Reply to: RE: It's basic acoustic physics. Dispersion widens with... posted by SteveJewels on March 21, 2021 at 17:53:10
        
        "lower frequency". Maybe this will help.
        
        Mark in NC
        "The thought that life could be better is woven indelibly into our hearts and our brains" -Paul Simon
        https://www.soundandvision.com/content/dispersion-show-and-t (Open in New Window)
RE: What to make of the Audio Science Review of the Magnepan LRS ? - Davey 16:17:44 03/20/21 (0)
I wouldn't make anything of it really.
The speaker confounded Amir and his test regime right from the start.
Lack of floor reinforcement contributing to the measurement and numerous other variables that informed his conclusion incorrectly.
And then a complete lack of humility regarding any discussion on it.
Regardless, this has already been discussed here on the MUG a number of months ago. (Search down a few pages.)
Dave.

Edits: 03/20/21
Pay no attention to most LRS measurements - Mike K 10:22:01 03/20/21 (0)
You have to actually listen to them, and you will know - immediately -
just how good they are. And after a few weeks of break-in? You'll
really know how good they are.
Whether or not you can observe a thing depends upon the theory you use. It is the theory which decides what can be observed. - Albert Einstein
Sympathy... - Tromatic 09:01:10 03/20/21 (6)
For measurment geeks. I can't imagine any circumstances where they enjoy life.
- Hey, I enjoy life 76.3dB of the time, 89.2dB when 'A' weighted! (nt) - 13th Duke of Wymbourne 22:39:16 03/22/21 (0)
  nt
- There must be some correlation between measurement and hearing though ? - peppy m. 09:10:51 03/20/21 (4)
  So I am thinking that planar dipole speakers are simply very hard measure correctly.
  
  And I'm wondering how Magnepan measure their speakers ?
  
  Magnepan surely must measure their speakers during development, and must have by now learned how to correlate those measurements with what they are hearing. Right ?
  - RE: There must be some correlation between measurement and hearing though ? - josh358 17:23:59 03/22/21 (0)
    Yep. They've been doing this for many years, and have a good idea of which measurements matter. Certainly not the ones that Amir made.
    
    You can tell a lot more about the behavior of a Maggie by just putting it in a room and measuring at the listening position than you can with the Klippel. It's the only way to get a sense of a dipole's bass and midbass performance, or the only way that doesn't involve some heavy calculations, anyway.
    
    The essence of it, I think, is that Amir was trying to open a can with a bottle opener. He would have done better just to put the speaker in a living room and measure it with a $70 measurement mic. There are so many reasons why his approach doesn't work that I can't list them here.
  - RE: There must be some correlation between measurement and hearing though ? - jubal62 05:12:44 03/21/21 (0)
    I found this interesting. In the Sony manual for their surround sound receivers it states that when using the microphone for auto speaker setup that this will not work with dipole speakers. That tells me that you cannot measure dipole speakers in a convention way.
  - RE: There must be some correlation between measurement and hearing though ? - hahax@verizon.net 20:40:44 03/20/21 (0)
    Where have the standard measurements, frequency response, distortion, etc. ever described the sound of a speaker, especially does it sound 'live' rather than like a clean wide band radio? And I believe in measurements that at least ultimately will describe a speaker. After all it's just an electrical mechanical system. And I do believe there are some measurements that will better describe 'live' sounding reproduction.
  - yes and no - farfetched 10:11:44 03/20/21 (0)
    Of course there are measurements. For example, the tautness of the mylar has tolerances. The rigidity of the frame has tolerances. And then there is the nitty gritty of how the tech works, which I have no clue.
    
    There are many, many measurements.
    
    But has *any* audio reviewer figured out how to evaluate maggies by giving us the "measurements that tell the tale" so to speak? Or any dipole for that matter?
    
    There are psychoacoustic complexities that make trying to "measure" a dipole (as if it wasn't always more interactive w/ the room than a box speaker)just outside the audio reviewer box.
    
    Hence why audio reviews of maggies w/measurements are argle bargle.
    
    / optimally proportioned triangles are our friends

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