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Magnepan LRS Speaker Review

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.
 

yourmando

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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.
Do you have a link or source for that? I'd be interested in seeing how Linkwitz' thoughts evolved on this topic.
 

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.
 

Joppe Peelen

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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.
 

Joppe Peelen

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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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yourmando

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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.
 
D

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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.
 

tuga

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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.

It is indeed a curious position if we take into account that no one listens to music using a single speaker.
Could it be a case of misinterpreting the data?

There's a chance that "the Quad fared poorly on pop music that contained significant hard panned components in the mix" because of its narrow horizontal dispersion.
 

Joppe Peelen

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It is indeed a curious position if we take into account that no one listens to music using a single speaker.
Could it be a case of misinterpreting the data?

There's a chance that "the Quad fared poorly on pop music that contained significant hard panned components in the mix" because of its narrow horizontal dispersion.


yeah even there esl63 did not had great dispersion... still sounded rather nice though :)
 

Blumlein 88

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Interesting, when I had Quad ESL-63s I came upon almost the complete set of the early mono Mercury Living Presence LPs. They sounded pretty good, and the discs were in pristine condition. I eventually played them using only one Quad. They sounded so much more right that way I always listened to them with one speaker only. With two speakers in mono there was too much faux space. Even in mono the early Mercury recordings were of good quality and gave a good rendition of the large space in which they were recorded. Covering that up with a dollop of extra spaciousness diminished how good those recordings were.
 

Wes

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I'd say that a dipole is better and worse than a cone/box speaker...

Speakers are flawed in numerous ways, unlike say electronics - or at least to a much greater degree than electronics. You have to pick the best sounding, or least bad sounding, mix of things in a multi-variate factor space.

It may be that only large panels can compete with cone/box speakers in that mix - I dunno as I've never heard a panel this small.
 

NTK

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any idea what kind of differences one might expect between the 2 ?
The "basis/fitting functions" given by the solution to the underlying PDE (partial differential equation), the Helmholtz equation, in the spherical coordinate system is efficient for modeling loudspeakers that have low aspect ratios (close to the shape of a cube). It is less efficient for panel shaped objects or thin and slander objects. What that implies is we need a lot of measurement points.

It is analogous to decomposing a square wave into a Fourier series. We need a lot of terms to accurately approximate the square wave with sines and cosines, because sines and cosines are not efficient in approximating squares.

The analysis performed by the Klippel NFS includes evaluating the fitting errors, which Amir has shown in this review. The radiation patterns of loudspeakers are much more complex at the higher frequencies, and can be seen by the higher fitting errors. It is less of a problem for the lower frequencies.
 

Joppe Peelen

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The "basis/fitting functions" given by the solution to the underlying PDE (partial differential equation), the Helmholtz equation, in the spherical coordinate system is efficient for modeling loudspeakers that have low aspect ratios (close to the shape of a cube). It is less efficient for panel shaped objects or thin and slander objects. What that implies is we need a lot of measurement points.

It is analogous to decomposing a square wave into a Fourier series. We need a lot of terms to accurately approximate the square wave with sines and cosines, because sines and cosines are not efficient in approximating squares.

The analysis performed by the Klippel NFS includes evaluating the fitting errors, which Amir has shown in this review. The radiation patterns of loudspeakers are much more complex at the higher frequencies, and can be seen by the higher fitting errors. It is less of a problem for the lower frequencies.

i can imagine. since the driver does not look as tall at low frequencies, as well as low end wont add or substract as much compared to higher frequencies with small delays due to distance. like measuring a line source slightly off axis vertically creating dips and peaks. expecially if the line is not so long. at the lower end not much changed :) well he did mention he took allot of points, more then usual. so who knows :)
 
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BYRTT

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Predicted in room response for Amir's spinorama analyze of LRS had been critized alot with reference to stereophile curve and Amir's own distortion graph, think often its hard to interpreet various ratios of plots scales to each other and therefor made them overlaid to same scales and corrected for their nearfield positioned microphones that cant see baffle dimensions is not infinite size when microphone sits so close, correction i used was thanks to member Joppe Peelen when he published curves of his own panel in room at 12,5cm and 100cm where i used their difference as the correction curve.

Index_spinorama.png


Left one is LRS stereophile nearfield curve overlaid to spinorama and right one is filtered as told at beginning..
PIR_examples_1a.png


Left one is LRS distortion nearfield curve of Amir overlaid to spinorama and right one is filtered as told at beginning..
PIR_examples_1b.png


Other PIR curve of a smaller panel size is left one that is Joppe Peelen's own creation at 100cm without any filtering and tweeter passband, right one is the predecessor Magnespan MMG measured in room at 100cm by Dick Olsher..
PIR_examples_1c.png


Think above tell we should be happy enough Amir own this anechoic wonder machine and share some more precise analyzes we can use to educate and reference/calibrate our own real world methods of acoustic benchmarks, had a hard try look for more PIR measurement into this thread because some postulate that over and over users PIR measurement show Amir's analyze is off for panels, but honestly the other Magnespan PIR measurement into this thread is really not for Magnespan LRS but other models so please forget that comparison as argument in those other panel are not same dimensions and technology.

Should there be some low end to hope for made below simulation of one floor boundary close to a line source using a Jeff Bagby spreadsheet and avarage of those 10 positions of a woofer piston to get a boundary correction filter, in the avarage grey curve..
Boundary_avarage_of_6inch_to_42inch_from_floor_200mS.gif


Above filter added to spinorama of Magnespan LRS based Amir's spindata..
PIR_examples_1x1x_500mS.gif



In quote below we have one member that ordered a set of LRS and we could hope for he would share a PIR curve down the road ..:)..
Went ahead and ordered a pair, though it seems it might be awhile(4-8 weeks) before I can hear them.
 
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RayDunzl

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I've lost the plot...

What is PIR?
 

No. 5

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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.
A better question might be: "how bad does a speaker need to measure for people to not enjoy it?"

And honestly, the LRS measurements don't look like they are that bad.
 

Joppe Peelen

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Predicted in room response for Amir's spinorama analyze of LRS had been critized alot with reference to stereophile curve and Amir's own distortion graph, think often its hard to interpreet various ratios of plots scales to each other and therefor made them overlaid to same scales and corrected for their nearfield positioned microphones that cant see baffle dimensions is not infinite size when microphone sits so close, correction i used was thanks to member Joppe Peelen when he published curves of his own panel in room at 12,5cm and 100cm where i used their difference as the correction curve.

View attachment 84483

Left one is LRS stereophile nearfield curve overlaid to spinorama and right one is filtered as told at beginning..
View attachment 84480

Left one is LRS distortion nearfield curve of Amir overlaid to spinorama and right one is filtered as told at beginning..
View attachment 84481

Other PIR curve of a smaller panel size is left one that is Joppe Peelen's own creation at 100cm without any filtering and tweeter passband, right one is the predecessor Magnespan MMG measured in room at 100cm by Dick Olsher..
View attachment 84482

Think above tell we should be happy enough Amir own this anechoic wonder machine and share some more precise analyzes we can use to educate and reference/calibrate our own real world methods of acoustic benchmarks, had a hard try look for more PIR measurement into this thread because some postulate that over and over users PIR measurement show Amir's analyze is off for panels, but honestly the other Magnespan PIR measurement into this thread is really not for Magnespan LRS but other models so please forget that comparison as argument in those other panel are not same dimensions and technology.

Should there be some low end to hope for made below simulation of one floor boundary close to a line source using a Jeff Bagby spreadsheet and avarage of those 10 positions of a woofer piston to get a boundary correction filter, in the avarage grey curve..
View attachment 84497

Above filter added to spinorama of Magnespan LRS based Amir's spindata..
View attachment 84498


In quote below we have one member that ordered a set of LRS and we could hope for he would share a PIR curve down the road ..:)..

VERY VERY NICE

im glad the fast measurement could be of any use. (although they dont look very nice :) ah well it was in my room , not a particular big one either )

I like the floorbounce graph to (nice you made a combination of the 10 positions), i had in my system a low pass around 400 hz when i first made the speakers, lowering the hump afterwards.
still a dynamic 8 inch driver in a cabinet can out perform most of the smaller panels when it comes to low end for sure. (and they should ofcourse , not being OB)


[EDIT]

i found some old measurements (2 years old) of my panels outside without filter (maybe a tiny bit cleaner result? , not gated 1/12 smoothing used , SPL not calibrated) (it does uses wires here instead of the current foil type conductors) but they look pretty similar to the one you used in the overlays , except that weird suckout and the 94 hz peak, are not present in the garden.

measured at 2 meters distance in a garden.

1600902136304.png
And here compensated it with a low pass , creating an acoustical crossover much higher. and getting rid of the peak these all tend to have, or at least make it less dramatic
1600902165295.png

and here with the old tweeter , im at v8 or something by now. (forgot what that weird peak was at the top end)
1600902234868.png

same speaker (maybe with some minor crossover differences) in room @ 1.5meter, ofcourse no gating could be used :(
1600902345429.png
and the suck out is back once more :)

i also measured a SMGA at this same instance i measured the in room measurement above.
Green is a magnepan SMGA and blue was my contraption back then. measured @ 1.5 meter. ofcourse no gating could be used :(
1600903124489.png

not sure if you can do anything with them in the findings you posted above. i forgot i had these. i still got the REW files if you by any change need.
 
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