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In Reply to: RE: Test of LRS on Audio Science Review website posted by triamp on September 25, 2020 at 03:52:42
Agree completely -- the test methods were flawed -- and I and some others raised objections in that thread.
Davey pointed out that he measured the bass response *with the speakers lifted off the floor*, a fatal measurement error -- the bass response of a dipole will be seriousy screwed if you do that, owing to an acoustic short circuit around the bottom.
There are other egregious errors as well, not the least of which is that Amir did his listening tests with *one* speaker (sigh).
Fortunately, there was a lot of pushback from people who have actually *heard* Maggies! The negatives seemed to come mostly from people who hadn't, but felt themselves experts because they'd read the review.
Follow Ups:
I'm very wary of all the short-time burst FFTs and other reconstruction techniques to attempt to estimate 'quasi-anechoic' measurements when they are applied to speakers, planars, with driver dimensions which can be significantly longer than the wavelength being emitted. The Klippel system tries to do something with 'spherical harmonics' which is a decomposition for the wave/diffusion equation suitable for systems with certain spherical symmetries, more specifically, the finite-mode truncations (as always used) will work better for quasi point sources vs long line sources. (By the way the spherical harmonic structure & radial modes are the basis of decomposition of Schroedinger equation solutions as the electron wave function orbitals that help govern chemistry)The algorithms & measurements almost surely were NOT calibrated or designed for that situation, i.e. calibrated and validated for planars against results in full, large, expensive real anechoic chambers (which have to be big enough even there so that the long axis of the speaker is still 'small'!) with AES-paper level science.
I'm a hard core 'objectivist' but further we need to be skeptical of the conditions of the measurements and applicability.
Furthermore, these tests, *like all the Harman preference tests*, in single speaker mono. Alone, Magnepans are nothing special. The perceptual psychoacoustic magic happens to me only in stereo, with a difference stronger than conventional speakers, perhaps with spectral balance perceived changes more than box speakers.
Edits: 09/30/20
Thanks, interesting and informative.
So my opinion.
This ASR site is one of these 'let's create controversy' sites so people will talk about us and notice us. The easiest way to gain attention is to take a stance opposite of the majority. I'm going to listen to one speaker and give an opinion. Riiiight. It's a clown show and I wish people would stop bringing it up.
Pass Labs amps suck
Magnepans suck
Psaudio directstream sucks.
Not really sure how they rated any of the above but....Whatever.
...and they rated the Denafrips Ares 2 DAC as mediocre. It is more musical, less digital than their top rated (based on measurements) Topping DAC which every member of the ASR forum seems to own.
BEEEEHHHHH...
Amir insists that all DAC's sound the same, but likes to measure them anyway. Most of the measurements he makes are of things that would be inaudible to a dog.
If they do all sound the same, he should just suggest that people buy the cheapest.
Of course they don't all sound the same, but try to mention the obvious and they'll throw bottles and tin cans at you.
I did a careful and painstaking series of level-matched A/B tests and they did not sound the same; the Sabre DAC's have the infamous "Sabre glare."
I'm not even sure that this is much of a mystery. I'm guessing it's the infamous harmonic distortion bump, although the overpeaked filters may contribute as well; ESS says they aren't correct, but sound good.
Amir doesn't think that ESS is correct about their own DAC's.
But kind of unfair to argue with somebody who isn't here.
Josh -
I read/skimmed all 700+ posts on that yesterday (yeah, I have no life). I thought your replies were cogent, well thought out, and relevant to the reality of listening to the LRS, properly setup, as a pair, in a typical listening room. Obviously the speaker has limitations both as a function of size, design, and price point, but measurements do not always tell the story on what speakers sound like. More likely they do somewhat with a standard box monopole but not on a dipole panel.
I found it interesting that none of the posts referencing other panels, varying Maggies and the laundry list of ESL, touched at all on my beloved LFT8. I always feel like such a dark horse but I still think they are a solution that overcomes a lot of issues and combines the best of planar, ESL, and piston. The dual magnet vapor deposited voice coils are fast, the xvr transition from mid to tweeter at 10K is seamless, the xvr transition to the 8" woofer at 180Hz is the only hybrid I have heard that doesn't have a hump that I can hear and it has usable response below 30Hz in my room. Ah well, better to go unnoticed.
I have gotten a lot of useful information from ASR but there is a certain mindset over there from many that makes me wonder if they actually listen to music? Of course there are forums that are the antithesis of ASR and keep the snake oil industry alive and well. Between measurement and observation somewhere in the middle lies truth.
These arguments always remind me of an interview I read with Dave Brubeck many years ago. I think it was back in the 80's in either TAS or Stereophile, when they were both still little trade journal sized books. Dave was going on and on about the music they were listening to and the interviewer just couldn't get past his frustration over Dave's system consisting of a stack of mid-fi gear piled on top of one another and the asymmetry of the speaker positions, one with a chair covered in laundry set in front of it. I know plenty of musicians who care about good audio reproduction but given a choice I'd rather have ability to "hear" music like Dave Brubeck, regardless what it is coming from.
Heh, yes, in-between is where the truth lies, but some of those guys are fanatics who wouldn't believe that the sky is blue unless it had been demonstrated in a double-blind peer-reviewed study.
OTOH, there are some excellent and knowledgeable people on the site -- and they aren't the same as the true believers.
The LFT8's are a curious case -- widely respected, but they don't get much attention, perhaps because they've been the same for longer than most of us have been alive!
sbrook, there are a few of us ET LFT-8b owners around. For some reason, most Maggie owners are just not interested in the ET's. I have both (LFT-8b and LFT-4, and Tympani T-IVa), along with the QUAD ESL.
I could have been a Maggie owner but for footprint. My first exposure to actually listening to them was an extended session at Lyric hi-fi in NYC with a set of 1.6's and I found them utterly rapturous. I subsequently auditioned a set of MMGs in home back in Florida. While a sub would have been desirable and better mounts, I loved the sound.
I hemmed and hawed between 1.6 and MG12 but I just couldn't handle the visual footprint in my living room. The MMGs had established that the room could support it (the wall behind them encompassed 8 linear feet of sliding glass)but the bigger panels would really block the view. Surprisingly my wife was okay with either but I was the one who couldn't commit.
The 13" width of the ET made them ideal. Bought unheard strictly on reading was a bit of a leap of faith but I have never been sorry. $1350 at the time for the 8A with the Sound Anchor stands was an obscene bargain and the additional $400 for the 8B tweeters was well worth it.
I still feel in the right room a set of MMGs with a small fast sub could have been all the speaker I needed.
It's interesting that on a forum that eschews subjective evaluation he uses (for speakers) subjective evaluation to confirm what he's not measuring. :)
Anyways, I don't think the measurement results are so much about dipole short-circuiting, but rather lack of boundary reinforcement. Even a typical box speaker measured well above the floor would measure differently when sitting on the floor. This is a simple 2pi/4pi environment effect that would manifest with all speakers.
However, typical box speakers are usually designed for above floor usage, whereas the Magnepan speakers are designed to sit on the floor. This is the essential "issue" with the PIR noted. The NFS claims to encompass that discontinuity as result of the measuring scheme......but I'm not convinced it's effective for all types of speakers. After Amir has tested another half dozen (or so) floor-standing dipole speakers then maybe the issues will become clearer.
Now, nobody is going to accuse the MMG/LRS of having room-filling bottom two octaves bass. They are NOT legitimate full range speakers and do need a sub-woofer to be considered such in a typical domestic situation. But, to characterize them as having "no bass below 300Hz" is not correct.
Dave.
.
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