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Magnepan LRS Speaker Review

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Measuring drivers individually is mostly for measurement efficiency and practicality. But when a certain point of complexity is reached (e.g. CBT's with a couple of dozen drivers) it will probably become a necessity. For large panels, I don't know if there are solutions other than lots and lots of measurement points.
http://www.klippel.de/fileadmin/kli...Notes/AN_70_Directivity_of_Speaker_Arrays.pdf
View attachment 84347
[Edit] For large (and mostly flat) panel speaker, planar NAH may be more suitable than spherical NAH, but I am pretty certain the Klippel NFS doesn't do planar NAH.
any idea what kind of differences one might expect between the 2 ?
 

Vasr

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If you want the easy way out, all you need to say is something along the lines of, "A direct measurement is a measurement that is directly taken."
Works for me and for anybody that isn't into pedantic/philosophical nitpicking. ;)
 
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Yep!

Nope! I can't spit that out in a few minutes ;)
But of course you can quickly try out what happens if for example the backside sound radiation is damped a little bit and additionally a first order lowpass is realized from 500Hz - so the dipole is not ideal anymore.

Then the free field result (4m distance) is much better (red curve is SUM):
View attachment 84330
i understand !! i dont expect you to spit them out :) i just wondered.
mine might look a bit different because of it (although mine is not gated anyway , so mine are influenced by my room to) so who knows :)

anyhow thanks for the sim !
 
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Francis Vaughan

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in conjunction with a compatible interpretation of quantum mechanics such as the many-worlds interpretation
Well yeah. Assuming that compatible model. My point is that that is a philosophical question that is still totally open. It gets near religious talking about which if any of those models to use. Personally I think many worlds is a very weak model to choose. But I can accept that many others find it the most appealing of what is a pretty poor set of choices. Decoherence is a key part of the puzzle, but IMHO alone insufficient to close the problem. It shifts the goalposts more than answers the question.
 

BillG

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But I've never heard anything like these Maggies.
When I reconnected my previous B&W box speakers and listened all I could hear was a box. Surprising to me since I never heard the box before. Clearly, for me,in my room, there's something going on with the LRS that the measurements aren't ,or can't, measure.
I can make eliminate the boxiness of a pair of box speakers by aiming one of them at a wall angled in a way so that a lot of the sound is scattered with a good portion bounced to my listening position and leaving the other aimed at directly at me. The result is something akin to an all encompassing sound field and quite marvelous to behold. In terms of the physics, I can't say since I've never bothered to research it. However, all of this - the time delay between the two sources, frequency response, and phasing - can be measured.
 
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I own the Maggie LRS and love them for me they are perfection! Driving them with a Hegel H160 integrate + Sumiko S.9 sub... All in I got it for $2500 and am very happy for the money invested. Yes they are finnicky for placement and require a significant space from the back wall (e.g. 3ft min). I keep them against the wall when not listening and then move them out when I'm using it. There is a very defined sweet spot based upon the twitter ribbon positioning. They are also very finnicky with their amplification but the Hegel pairing is quite great.
 

RayDunzl

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You love them, or you love them not...

FlimsyFrayedBagworm-small.gif
 

anmpr1

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I believe that amirm's excellent measurements and expert criticisms of the LRS are all correct. So why do they sound so good to me in my room? I've owned lots of dynamic box speakers in my 50 years as an audiophile. Some of them very good. But I've never heard anything like these Maggies. When I reconnected my previous B&W box speakers and listened all I could hear was a box.
The boxy thing is something I have thought about a lot over the years. I know a couple of dyed in the wool dipole enthusiasts, and the whole boxy sound comes up a lot. So, my personal take on it is that indeed, some boxes have enough internal resonant modes that are not well managed that they colour the sound.
No matter how much designers brace, damp, partition, or otherwise attempt to 'de-box' the enclosure, there will always be a box, and it will always 'color' (or otherwise artificialize) the sound. Then there are baffles.

In the forties and fifties, very efficient and very large boxes and horns were an attempt to debox. All with varying degrees of success. Edgar Villchur made the box small, domestically unobtrusive, and relatively inexpensive. Since then small boxes claimed dominance, and since then manufacturers have been working ways to get rid of the very box. Siegfried Linkwitz spent his life attempting to debox (and debaffle) in order to rid himself of the effect.

Negative (or at least questioning) comments about dipoles are valid, and well noted. Panels have their own peculiarities--often times disqualifying (depending upon one's choice of the varying loudspeaker trade-offs). But boxiness is not one of them.
 

Francis Vaughan

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No matter how much designers brace, damp, partition, or otherwise attempt to 'de-box' the enclosure, there will always be a box, and it will always 'color' (or otherwise artificialize) the sound.
Maybe. One thing I notice constantly is that what actually is the nature of "boxy sound" is not clealry described. It is quite easy to remove all internal resonance from a box. Similarly make the construction of the box resonant free. It isn't exactly rocket science. Whether this removes the boxy sound is another matter. But killing off those particular issues isn't hard.
The trouble we have is that all loudspeaker reproduction is inherently flawed. This also isn't exactly rocket science. We know a-priori that it is intrinsically impossible to reproduce the original event. Everything is a compromise and the trick is is picking your battles. Dipole speakers pick one specific battle - that of trying to generate an enveloping sound in the room that seeks to emulate the spaciousness found in a performance venue in a space that intrinsically is not able to support such a sound. So it is an illusion. Linkwitz theorises about making life easy for the ear-brain system to build a new illusion of a spacious immersive experience from a simple limited two channel recording. He is quite clear about it being an illusion. There is no pretense that it somehow magically recreates the real sound present during the recording. Just a pleasing illusion. It is artificialising the sound just as much as reproducing the sound out of a boxed speaker might. Just in a different manner, but arguably in a more heavy handed manner.
IMHO there are some important things going on here that are worthy of deeper work. What seems to get in the way of this are the polarised viewpoints from each side, expressed here just as badly as anywhere else.
 

Newman

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....It's true that the orientation relative to a room-mode null matters, but in practice, dipole woofers have smoother in-room response -- this is apparent both in emulation and real-world measurements and likely a major factor in their more natural sound. A speaker designer I know tried some experiments and found that he could equal the quality of two dipole subwoofers but that he needed a swarm of four dynamic subwoofers to do so. On the other hand, Siegfried Linkwitz believed that the steady-state frequency response was not the differentiator:

"I have investigated possible reasons for the qualitative difference between monopole and dipole bass reproduction by in-situ measurements and scale model experiments. I am convinced that the steady-state low frequency response is a poor indicator of the quality of bass reproduction, other than to point to the one or two modes that need to be equalized. The strongest correlation between measured data and subjective impression appears to come from a modulation-transfer-function measurement which is analyzed in the time domain. For example, when a short length of a 100% amplitude modulated signal with a carrier to modulation frequency ratio of 10:1 is used as stimulus, then the room response reduces the depth of modulation and increases the burst duration for different frequencies and room locations. A pattern seems to appear whereby the modulation envelope is subjectively preserved more frequently with a dipole than a monopole. This correlates strongly with the impression that bass reproduced by a pair of dipole woofers is more articulate and thus more realistic of the recorded source."

Interesting, no?
Actually Linkwitz recanted the above early thoughts in later life, and agreed with Toole's position.

Sorry for late replies, I am just catching up on this thread.
 

Newman

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This thread is fascinating reading. Learning lots about dipoles
Beware the many pages of misinformation on said topic in this thread. Mostly coming from dipole owners who, in all innocence, think the too-numerous dipole myths, that have accumulated over the decades, are technically sound.
 

Francis Vaughan

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A quick re-reading of Toole's Sound Reproduction 3rd edition, 7.4.2. notes an interesting experiment. Toole tested a Rega Model 3, and Kef 105.2 box speakers, and a Quad ESL 63 in a blind, robotic switched test environment. The results specifically showed that the Quad ESL, when listened to in mono, received markedly low marks for sound and spacial quality, but received marks close to the others when listened to in stereo. Toole closed by suggesting that evaluating in mono is important because it lets you "find out what you really have" and that stereo listening should be left for demonstration and impressing everybody. It is a curious position, given this is an artificial use case.

He also noted that the Quad fared poorly on pop music that contained significant hard panned components in the mix, and fared well on classical and jazz recordings that intrinsically contained real spatial content.

This study was done in 1985. He didn't have the advantage of technology like the Klippel to measure the speakers, so some of the analysis is a bit handwavy. It would be most interesting to measure an ESL 63, and maybe a 105.2 Given we have Toole's experiment results, there may be some useful insights to be gained.
 
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I think the question is not so much if a dipole is better or worse then a a conventional speaker... what i think and i speak for myself and i guess some others, is people wonder how come the thing measure so badly, while allot of people still enjoy them. in this case the LRS is one of the most interesting to test, since there is so much hype. i heard and made quite allot of the same sort of planars, and i often as well thought WHY is everyone hyping this new product while technically they are the same as the ones they already made years ago. the size for instance is rather small, not ideal for such a speaker, they use all out foil.. a marketing thing that really does there job. yes foil has benefits over wires as wel as downsides. especially down low there is not much to gain. depending on how high up the midbass panel plays there is either nothing to gain or a tiny bit. there are some misinformation about using foil traces like being lighter... being the weirdest one i think.

First of all i really like the idea of making decent measurement besides the typical high end sources and create a more reliable database, also the fact he does them with allot of effort put in and also from people on the forum for free !!!

i looked at the measurements and assumed a few things that apparently are not true when measured with the Klippel system, but the question rings why does it measure so bad and does indeed the klippel method measure a long flat planar the way it should have been>?

NTK said a few post back " For large (and mostly flat) panel speaker, planar NAH may be more suitable than spherical NAH, but I am pretty certain the Klippel NFS doesn't do planar NAH. "

So that , still makes me wonder if the measurements are completely accurate, including the overlay i posted a fe posts back noone commented on where you can see the result you get when you take your reference on axis measurement slightly to high or to low of such a line source.

i would be interested how a measurement would look when you do a measurement @1.5- 2 meters with gating and see what the top end would look like (taking much care about the vertical on axis). maybe it does look the way it does ! who knows.
The low end remains a huge problem and might well be 100% accurate, i dont doubt the fact such small panel has low output all the way down to 50hz. while the bigger SMGA with a slightly bigger pannel and baffle goes down to 60 hz. it makes a rather big difference in output.

in short, i never heard this particulairy model and i only see huge hyped up posts about them, i usualy take them with a grain (or more) of salt, but this looks so bad that i wonder if something might have gone wrong.

please dont burn me down just because i doubt something, and yes i am sure im not as well educated about modeling as some around here.(if you ever seen a video of mine, you know i just try allot of different things, some work some suck)
And maybe we should leave that OB VS CLOSED speaker debacle. i mean it gets us nowhere and it was not the point of the measurement i believe?
 

richard12511

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I think the question is not so much if a dipole is better or worse then a a conventional speaker... what i think and i speak for myself and i guess some others, is people wonder how come the thing measure so badly, while allot of people still enjoy them.
One possibility is that psychoacoustics is making people think they like the sound of something they really don't. It's possible that those people would rate the speaker poorly under blind conditions. Given the hype surrounding these speakers from all the rave print and youtube reviews, I imagine the placebo is strong here.

They could also just have different preferences than the majority. Toole/Olive's research around measurements tells us what most people should prefer, but it's no guarantee for any one individual. Individual preferences can shake things up.
 
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One possibility is that psychoacoustics is making people think they like the sound of something they really don't. It's possible that those people would rate the speaker poorly under blind conditions. Given the hype surrounding these speakers from all the rave print and youtube reviews, I imagine the placebo is strong here.

They could also just have different preferences than the majority. Toole/Olive's research around measurements tells us what most people should prefer, but it's no guarantee for any one individual. Individual preferences can shake things up.
i agree most certainly ! placebo is huge :) and they might have been over hyped (at least that was my feeling) with reviews on youtube of sponsored products (without mentioning it !) where people where raving about all kinds of details like rhythm, speed, singer in the room, curtains swooped away etc etc etc the usual even the if they dont sound good you need better equipment... all the classics.
 
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I'm going to partially disagree with you on this, speaking as someone who owns LX521's and has used mainly dipoles and planar speakers for the past 20 years. I think they'd measure much better than this low-end Magnepan did but I wouldn't be surprised if a Revel or cheap JBL measured as well or better. OTOH, I think that if someone were to listen to a pair of properly engineered dipoles properly setup in a room they'd hear things not conveyed by a positive Klippel NFS analysis. No science to back up my hunch as I don't have a Klippel NFS system setup in my garage.

Some reading to backup my hunch.
I've always wanted to see good polar response measurements of the Linkwitz dipole designs, but haven't come across any. A spinorama and polar diagram showing perfect dipole directivity would be ideal. It certainly wouldn't hurt to have well controlled directivity.

Sadly, the closest thing I've found was running across this Earl Geddes talk where he showcases the directivity of several speakers with his software tools.

"Let's look at the Orions...I have no idea why this speaker is rated so well, because it just doesn't measure that well."

"It has good directivity in lower frequencies, but here [at around 500 hz] we have almost no directivity at all"

"...You can see the crossover point here. It's not well done."


I'm not sure if Linkwitz believed that dipoles are inherently superior. He also praises other controlled directivity designs and states how similar his own Pluto & LXMini designs sound vs his Orion & LX521.

He's also a fan of cardiod and lavished praise on the Kii 3. "Could that be the ultimate?" [crossing it at 80hz to large dipole subwoofers]

https://linkwitzlab.com/Constant_directivity_louds.htm

I've been re-reading a lot of Linkwitz' stuff lately, and nothing seems to contradict the conclusion that having a good spinorama will generally have better results. His criticisms of box speakers are of "typical" designs with poor directivity control, for example.
 

dreite

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Actually Linkwitz recanted the above early thoughts in later life, and agreed with Toole's position.
No, that is not correct.
SL continued to believe that controlled-directivity should be maintained to much lower frequencies than traditional speaker systems are capable of.
Dipole woofer systems are one way to address this, but other approaches are valid and becoming more mainstream with time.

Let's please not engage in revisionist history.

Dave.
 
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