Magnepan LRS Speaker Review

[Sir Sanders Zingmore]

Proximity to walls and ceilings is reduced as rooms become smaller. So is the proximity of the baffles to one another. This has a significant effect on the bass response of the speaker.

Do you mean proximity is increased ?

 

[Vladimir Filevski]

And what in the world makes you think that I would waste my time doing so? To design loudspeakers, I have to know something about how they measure and how they work.

So you don't have measurements to support your claims. I thought so...
It is not enough "To design loudspeakers, I have to know something about how they measure and how they work" as you think. No, You have to know almost everything about loudspeakers, to take courage to design them.

 

[josh358]

Do you mean proximity is increased ?

Heh, yes, good catch -- I'll go back and fix it.

 

[Newman]

That came from Wendell Diller at Magnepan (the designer of the LRS).

Yes, I didn’t think it was going to be credible. The waffle about box subs was a giveaway.

Honestly, you deserve the company award for top marketing mouthpiece. You have been touting the company’s words as gospel literally from day 1, while disputing numerous aspects of its poor measured performance as irrelevant or inapplicable. Not once have I seen you question the maker’s claims, even though they are largely nonsense and marketing, in your near-150 posts in this thread.

Here is you today: “The LRS, being a small speaker, was designed for small rooms. In general, the larger the room, the larger the panel of a dipole loudspeaker has to be to maintain flat bass response. If the LRS had been designed with more midbass output, it would have had too much bass in the rooms for which it was optimized. But this design choice means that in a large room, it starts to sound like a midrange!”

…and here is you on the day Amir’s review was published, a year and a half ago, in your first post in this thread: “According to Magnepan, if the room is large, the LRS's lows will disappear, since the panel is so small -- the baffle of a dipole woofer has to be sized for the room, the larger the room, the larger the baffle. They don't recommend the LRS to someone who has a larger room -- as Wendell Diller put it, in larger room, the LRS turns into a midrange!”

It’s the same! You have gone full circle and learned nothing!

The trick to ‘waffle words’ of the sort you quote from the company above, is that they ‘seem to be’ vaguely logical by containing a hint of truth in principle, but never ever backed up with measurements. For example, Amir posted his in-room response:-

That includes the room gain of a certain room size, so you only get to add the difference in room gain for a smaller room, which is just going to be a bump, not a shelf. And the rest of the in-room response remains very rough.

But what do you expect from a speaker with off-axis behaviour like this through the mid and upper frequencies? :-

The idea that the above sound isn’t coming off the side walls, just because it’s a panel, is indefensible. Of course it is (after all, there is more than one side wall), and the front and back walls too. You are going to hear ^^^ that.

And finally, the on-axis reponse issues cannot be denied. Panel, box, whatever, the on-axis that Amir measures above 250-ish Hz is perceived as a distinct thing to the off-axis/room contribution, and yes it is applicable to this speaker as any other. The 5 dB drop from 350-1200 Hz, followed by several uneven lifts and hollows, will be audible and not judged as better than flat.

Repeating myths from the mouths of a hammer-and-nails speaker builder, so uncritically, will not go down very well here.

 

[FrantzM]

Used to love them Magnepans. Owned a few.
Knowing enough, today, to no longer care, want or yearn for, them.

Peace.

 

[josh358]

Yes, I didn’t think it was going to be credible. The waffle about box subs was a giveaway.

Honestly, you deserve the company award for top marketing mouthpiece. You have been touting the company’s words as gospel literally from day 1, while disputing numerous aspects of its poor measured performance as irrelevant or inapplicable. Not once have I seen you question the maker’s claims, even though they are largely nonsense and marketing, in your near-150 posts in this thread.

Here is you today: “The LRS, being a small speaker, was designed for small rooms. In general, the larger the room, the larger the panel of a dipole loudspeaker has to be to maintain flat bass response. If the LRS had been designed with more midbass output, it would have had too much bass in the rooms for which it was optimized. But this design choice means that in a large room, it starts to sound like a midrange!”

…and here is you on the day Amir’s review was published, a year and a half ago, in your first post in this thread: “According to Magnepan, if the room is large, the LRS's lows will disappear, since the panel is so small -- the baffle of a dipole woofer has to be sized for the room, the larger the room, the larger the baffle. They don't recommend the LRS to someone who has a larger room -- as Wendell Diller put it, in larger room, the LRS turns into a midrange!”

It’s the same! You have gone full circle and learned nothing!

The trick to ‘waffle words’ of the sort you quote from the company above, is that they ‘seem to be’ vaguely logical by containing a hint of truth in principle, but never ever backed up with measurements. For example, Amir posted his in-room response:-
View attachment 197355

That includes the room gain of a certain room size, so you only get to add the difference in room gain for a smaller room, which is just going to be a bump, not a shelf. And the rest of the in-room response remains very rough.

But what do you expect from a speaker with off-axis behaviour like this through the mid and upper frequencies? :-
View attachment 197356
The idea that the above sound isn’t coming off the side walls, just because it’s a panel, is indefensible. Of course it is (after all, there is more than one side wall), and the front and back walls too. You are going to hear ^^^ that.

And finally, the on-axis reponse issues cannot be denied. Panel, box, whatever, the on-axis that Amir measures above 250-ish Hz is perceived as a distinct thing to the off-axis/room contribution, and yes it is applicable to this speaker as any other. The 5 dB drop from 350-1200 Hz, followed by several uneven lifts and hollows, will be audible and not judged as better than flat.

Repeating myths from the mouths of a hammer-and-nails speaker builder, so uncritically, will not go down very well here.

Actually, Newman, I have owned Maggies for 40 years because they suited my needs. I am a fan of Maggies, yes -- but I'm a fan of other speakers as well. If you've read what I said, you know I have said that I would not personally recommend the LRS to people who listen primarily to rock (though many disagree -- it really depends on how people use the speaker). Not without a subwoofer, anyway. The LRS shines in its role as a $750 speaker that reproduces good recordings of acoustical music realistically, when played at moderate levels. I have not heard a $750 speaker that equals it in that regard, and that is why it has received such an enthusiastic response from audiophiles and the press.

I met Wendell Diller some years ago through the Planar Asylum and we became friends. In the last couple of years, I have had an unpaid role in the design of their loudspeakers. I have said that here. I speak to Wendell very few days, and I would know if he were spouting "marketing BS." If I said the same thing about small rooms a year ago, it is because it was as true then as it is now. And, really, if you'd read my communications with Amir before he did this review, you would know that the question I posed was why Maggies sound good when they don't measure particularly well. (Obviously, this depends on the model -- at the opposite extreme, their flagship 30.7 measures +/- .5 dB in the midrange and follows their house curve from below 20 Hz and far beyond 20 kHZ.) It is a question that still interests me, as agenda-driven discussion does not.

Amir's response curve merely demonstrates what I have been saying -- that the bass response of the LRS is fine in a real room, in fact, I'm surprised it went that low. There is a peak in the 400-500 Hz region in the far field. This is obviously a flaw. However, when you listen closer to the speaker, the response looks closer to this (quasi-anechoic at 50" averaged over 30 degrees + near field measurement below 300 Hz):

Small room speaker, right? Ordinarily, they will be listened to a bit further away than this. They were designed to have the proper response at that listening distance in a small room. As Wendell himself put it to me a year ago, they sound like a midrange in a larger one. (Jonathan Valin made pretty much the same observation in his review.)

Per John Atkinson, the suckout at 3000 Hz fills in if you position the tweeter a bit further away than the woofer; also, the default configuration of the tweeters is with the 1 ohm series resistor in place -- without, the highs will be tilted up, as they are here. The goal in designing these speakers is for a .5 dB/octave decline in amplitude as a function of frequency, and with the resistor in place, and the listening axis correct, it should be roughly that.

I am not sure why Amir measured on the tweeter axis -- as I said, that isn't the right place. The behavior in the crossover region is characteristic of a lateral crossover and is likely exacerbated by excessive distance between the acoustical centers of the woofer and tweeter (the three-way models don't have this issue). Lateral tweeter response is lobed because the tweeter is too wide (most tweeters are, but this one is even more so). (The true ribbon models have a 1/4" wide tweeter ribbon and nearly ideal dispersion; you get what you pay for.) In any case, with the speakers properly toed in and toed back, these issues (and the sorry vertical dispersion) aren't a serious problem at the listening position.

Wendell is aware that there is a 400-500 peak in some rooms and configurations, and has used acoustical treatment to tame it when that occurred.

"The idea that the above sound isn’t coming off the side walls, just because it’s a panel, is indefensible." Huh? These are dipoles. Have you rewritten the laws of physics? They have little output at the first reflection off the side walls, something that is easily measured, not that it has to be. That does not make any sound measured in the far field "disappear," a proposition that is absurd. What it does do is affect imaging and timbre and, below the Schroeder frequency, improve bass smoothness.

I do not repeat "myths." I am interested in a discussion with those who have heard the speakers and are curious about the relationship between the measurements and what one hears on a good recording with the speakers properly set up in a suitable room. As to speaker builders, I am more inclined to listen to them than to non-speaker builders.

 

[NTK]

... I have said that here. I speak to Wendell very few days, and I would know if he were spouting "marketing BS." ...

Dr Toole seemed to have a slightly different perspective. (Quoted post was his response to Wendell's video in the first post of the thread.)

The Magnepan description at 2:15 minutes or thereabouts, describing "Toole's" research is totally wrong - an outright lie. The first requirement of a good sounding loudspeaker is its on-axis response, second, it's early reflection response, and at low frequencies, its steady-state in-room response. Sound power by itself is a poor correlate of overall sound quality. It is useful because it is a component in the traditional metric of directivity index, and if it is smooth, it can help confirm the absence of resonances.

BS baffles brains, especially when people don't read and promoters of products are simply either ignorant or deliberately misleading. I suspect both in this case. He is using it only to get my name in there. It pisses me off !!!!

 

[DonH56]

I have heard the speakers, and owned a pair in one flavor or another since 1979, though they are not currently my primary speakers. I have also measured them many times in various ways over the years (none recently, but physics has not changed). I like them as they are, but they do not magically have the ability to "rewrite physics", and attributing their nature to the room seems disingenuous at best. You could make a similar argument for any speaker with limited bass response, e.g. that it will sound better in a smaller room and in the near field.

 

[josh358]

Dr Toole seemed to have a slightly different perspective. (Quoted post was his response to Wendell's video in the first post of the thread.)

Floyd Toole is unwittingly wrong regarding Wendell's intention here. I know because I am partly to blame for the confusion. I had been discussing power response with Wendell, who was wondering whether it would make an interesting topic for a presentation -- he likes to do presentations like that, rather than just saying "Listen to our speakers and how great they are." I was referring to Toole's early observation that speakers that were flat on axis didn't always sound good, and that the reason they didn't was that they had poor dispersion at the crossover points and that this led to poor power response.

Somehow, that got lost in the translation, and it sounded as if Wendell was saying that the only thing that mattered was power response. Needless to say, it isn't -- on-axis response is the first design consideration, after which power response is optimized.

One thing I regularly see, having known and spoken to Wendell over the years, is that people misunderstand Wendell's motives and assume that they're cynical. In fact, he's a remarkably principled guy who attended divinity school! He stubbornly refuses to adopt some common marketing techniques, such as bragging about unobtanium mouse liver driver cones, etc. -- he believes that the focus should be on the sound, not on audio bling and absurdities like exotic hookup wire.

So this actually came out of respect for Dr. Toole's work and I was chagrined when I saw his post, in part because I felt responsible for the mess. Jim Croft said, after I posted our response (mine, really -- I proposed it and Wendell signed off on it) that he would have put Wendell in touch with Floyd to clear up the misunderstanding. I wish Jim had been involved sooner, because that would have been much better than what I did.

 

[Shazb0t]

Floyd Toole is unwittingly wrong regarding Wendell's intention here. I know because I am partly to blame for the confusion. I had been discussing power response with Wendell, who was wondering whether it would make an interesting topic for a presentation -- he likes to do presentations like that, rather than just saying "Listen to our speakers and how great they are." I was referring to Toole's early observation that speakers that were flat on axis didn't always sound good, and that the reason they didn't was that they had poor dispersion at the crossover points and that this led to poor power response.

Somehow, that got lost in the translation, and it sounded as if Wendell was saying that the only thing that mattered was power response. Needless to say, it isn't -- on-axis response is the first design consideration, after which power response is optimized.

One thing I regularly see, having known and spoken to Wendell over the years, is that people misunderstand Wendell's motives and assume that they're cynical. In fact, he's a remarkably principled guy who attended divinity school! He stubbornly refuses to adopt some common marketing techniques, such as bragging about unobtanium mouse liver driver cones, etc. -- he believes that the focus should be on the sound, not on audio bling and absurdities like exotic hookup wire.

So this actually came out of respect for Dr. Toole's work and I was chagrined when I saw his post, in part because I felt responsible for the mess. Jim Croft said, after I posted our response (mine, really -- I proposed it and Wendell signed off on it) that he would have put Wendell in touch with Floyd to clear up the misunderstanding. I wish Jim had been involved sooner, because that would have been much better than what I did.

All I've learned from reading your waffle in this thread is that you should be marked on the forum as somehow affiliated with the manufacturer so that normal readers don't take your insistent claims regarding "physics" too seriously.

 

[josh358]

I have heard the speakers, and owned a pair in one flavor or another since 1979, though they are not currently my primary speakers. I have also measured them many times in various ways over the years (none recently, but physics has not changed). I like them as they are, but they do not magically have the ability to "rewrite physics", and attributing their nature to the room seems disingenuous at best. You could make a similar argument for any speaker with limited bass response, e.g. that it will sound better in a smaller room and in the near field.

While a small room will emphasize the bass of any speaker (and, sadly, make it rougher), the effect of the size of the planar baffle vis-a-vis room size isn't present in a sealed or ported enclosure -- it's unique to finite baffle dipoles. This is not rewriting physics -- it is a consequences of wave mechanics -- and it certainly isn't disingenuous.

One intuitive way of visualizing this is to ask yourself what would happen if the baffle were extended to meet the walls and ceiling. It would become an infinite baffle and as there would be no dipole cancellation, the bass response would go through the roof.

The rule with dipoles is that the larger the baffle, the lower the frequency at which bass starts to roll off at 6 dB per octave. What makes this complex is that in a real room, the size of a dipole baffle is in effect increased by proximity to room surfaces, and even to other baffles. This is well known and easily measured.

Regarding response in the near field, an open baffle woofer does not behave like an enclosed woofer as you move into the near field, or anything like. That's because the dipole cancellation doesn't occur when you're close to the speaker.

If you're interested, here is an excerpt from an explanation by Sigfried Linkwitz:

"The Magneplanar is clearly not a point source and, being open-baffle, it has an acoustic short circuit between front and back. This causes a 6 dB/octave low-frequency roll-off in the farfield response. So from all open baffle nearfield measurements you have to subtract first a 6dB/octave (= 20dB/decade) slope before you can sum the data with other farfield measurements. When you apply this correction to the MG3.6 woofer response you see that it flattens from 400Hz to 60Hz and shows a peak at 47Hz. Similarly the midrange has to be corrected before you can use it for the composite response. The actual room response is still different from this composite, though, primarily due to the effect of the floor on woofer radiation."

Magnepan Magneplanar MG3.6/R loudspeaker More Comments

Comments on Nearfield Measurements of Panel Speakers: (The following letters were received but were not published.) Siegfied Linkwitz comments Editor: The review of the Magneplanar MG3.6/R in the August Stereophile caught my attention. I am a proponent of open-baffle speakers because of their...

www.stereophile.com

If you're interested, I suggest you read the whole letter and look at the measurements.

 

[DonH56]

I never said it was a point source, I said it transitions to that behavior in the bass as you go below the panel dimensions. I'll stick with the wave mechanics I learned in my college grad courses, and have already mentioned them in a hand-waving way and provided a reference for those who want to dig deeper.

 

[Vladimir Filevski]

While a small room will emphasize the bass of any speaker (and, sadly, make it rougher), the effect of the size of the planar baffle vis-a-vis room size isn't present in a sealed or ported enclosure -- it's unique to finite baffle dipoles. This is not rewriting physics -- it is a consequences of wave mechanics -- and it certainly isn't disingenuous.

You are wrong, again. The effect of large baffle size is present in a sealed or ported enclosure, too!

One intuitive way of visualizing this is to ask yourself what would happen if the baffle were extended to meet the walls and ceiling. It would become an infinite baffle and as there would be no dipole cancellation, the bass response would go through the roof.

Also, if you extend the baffle of a closed box to meet the walls, ceiling and floor, the bass response will go through the roof! So?

Regarding response in the near field, an open baffle woofer does not behave like an enclosed woofer as you move into the near field, or anything like. That's because the dipole cancellation doesn't occur when you're close to the speaker.

But you (and everybody else) don't listen to your Magneplanars in a near field!!!

 

[josh358]

All I've learned from reading your waffle in this thread is that you should be marked on the forum as somehow affiliated with the manufacturer so that normal readers don't take your insistent claims regarding "physics" too seriously.

I have been clear here that I am a friend of Wendell Diller's and have done unpaid design work for Magnepan -- it is one reason I feel qualified to comment on these topics. I don't work for the company and I don't speak for the company; the opinions here are my own. Whether you want to call that "affiliation" is up to you.

Otherwise, I am tired of people who know fuck all about the physics of planar dipoles suggesting that my "insistent claims" should not be taken seriously. As the quotation from Sigfried Linkwitz above illustrates, I am merely stating principles of dipole operation that are well known to anybody with knowledge of dipole design. There are some people here who are familiar with those principles, and I welcome their comments. The others are best advised to keep their uninformed opinions to themselves.

Those who are genuinely interested in learning something about the design of dipole loudspeakers may want to read Jim Griffin's paper, "Design Guidelines for Practical Near Field Line Arrays":

https://audioroundtable.com/misc/nflawp.pdf

As well as perusing the wealth of information on Linkwiz's site:

Linkwitz Lab - Loudspeaker Design

Design and consultation in electro-acoustics. Fundamental concepts of sound reproduction in rooms. Detailed design information for DIY construction of a subwoofer and an open-baffle speaker with exceptional fidelity. Dipole loudspeaker design for true to the original sound reproduction with...

www.linkwitzlab.com

I am truly, truly getting tired of this. If you don't understand the basics of line source dipole loudspeaker design, don't pretend that you do.

 

[josh358]

You are wrong, again. The effect of large baffle size is present in a sealed or ported enclosure, too!

Also, if you extend the baffle of a closed box to meet the walls, ceiling and floor, the bass response will go through the roof! So?

But you (and everybody else) don't listen to your Magneplanars in a near field!!!

Sealed and ported enclosures do not suffer from 6 dB/octave dipole cancellation. You may want to read my excerpt from Sigfriend Linkwitz's comment above to get an understanding of dipole design, and I highly recommend the Griffin paper a well.

What you say about the near field isn't quite true either. A full-height line source behaves like an infinite line, and to the extent that effect is perfect (it isn't), you will be in the near field vertically whether you're an inch away, orbiting Saturn, or in another galaxy. Lateral behavior is a bit more complex, as it's dependent on frequency and room width. In practice, the LRS will fall off as 1/R^2, IOW, it will behave like a point source if you're sufficiently distant from the speaker. Up close, you will find that bass output increases substantially because dipole cancellation hasn't occurred. See the Linkwiz letter above.

 

[josh358]

I never said it was a point source, I said it transitions to that behavior in the bass as you go below the panel dimensions. I'll stick with the wave mechanics I learned in my college grad courses, and have already mentioned them in a hand-waving way and provided a reference for those who want to dig deeper.

Don, I'm not sure what you're saying here. Yes, it transitions as you go below the panel dimensions. In practice, you'll see the bass response increase when your listening position is close. I am not sure why anyone is disputing that, or for that matter, most of what I have said here. It is straightforward physics, born out by observation: a dipole with a small baffle will have depressed midbass response in a large room, and a dipole with a large baffle will have exaggerated midbass response in a small one, and similarly, bass response will increase as one moves into the near field. Does anyone deny this? Because it's easily measured and the physics is simple. And no, open baffle speakers do not behave like enclosed speakers, that's absurd. As I assume you but not everybody here knows, they suffer from 6 dB/octave dipole cancellation.

 

[DonH56]

Don, I'm not sure what you're saying here. Yes, it transitions as you go below the panel dimensions. In practice, you'll see the bass response increase when your listening position is close. I am not sure why anyone is disputing that, or for that matter, most of what I have said here. It is straightforward physics, born out by observation: a dipole with a small baffle will have depressed midbass response in a large room, and a dipole with a large baffle will have exaggerated midbass response in a small one, and similarly, bass response will increase as one moves into the near field. Does anyone deny this? Because it's easily measured and the physics is simple. And no, open baffle speakers do not behave like enclosed speakers, that's absurd. As I assume you but not everybody here knows, they suffer from 6 dB/octave dipole cancellation.

I took your original post to be debating the transition as part of taking the room into account. That is low bass, not mid bass, in my mind so apparently we were talking about different regions. Or as you said I just don't know f-all about it.

 

[josh358]

I took your original post to be debating the transition as part of taking the room into account. That is low bass, not mid bass, in my mind so apparently we were talking about different regions. Or as you said I just don't know f-all about it.

It's entirely possible! Honestly, I've lost track of the thread at this point. Too many threads.

 

[Vladimir Filevski]

Sealed and ported enclosures do not suffer from 6 dB/octave dipole cancellation. You may want to read my excerpt from Sigfriend Linkwitz's comment above to get an understanding of dipole design,

Conventional loudspeaker boxes do not have 6 dB/octave cancellation, but contrary to your previous post, front baffle dimensions do make big difference on measured low frequency response of conventional speaker boxes!
I do know what Dr. Linkwitz wrote about dipole design ... and understand it all. And I publish an AES paper about one specific type of dipole speaker ... and patented it... and on one occasion Dr. Linkwitz asked me, did I manage to sell my patent...

What you say about the near field isn't quite true either. A full-height line source behaves like an infinite line,

What a full-height line source have to do with what I said about listening dipoles in a near field?!
I said this:

But you (and everybody else) don't listen to your Magneplanars in a near field!!!

So, is it true, or not? Are you listening to your Magneplanars in a near field, or not?

 

[josh358]

Conventional loudspeaker boxes do not have 6 dB/octave cancellation, but contrary to your previous post, front baffle dimensions do make big difference on measured low frequency response of conventional speaker boxes!
I do know what Dr. Linkwitz wrote about dipole design ... and understand it all. And I publish an AES paper about one specific type of dipole speaker ... and patented it... and on one occasion Dr. Linkwitz asked me, did I manage to sell my patent...

What a full-height line source have to do with what I said about listening dipoles in a near field?!
I said this:

So, is it true, or not? Are you listening to your Magneplanars in a near field, or not?

I assume you're talking about the baffle step? Agreed. Planars have a baffle step as well, but below it, you have as you said that dipole cancellation.

Otherwise, as I said, you're *always* listening to a full height dipole in the near field vertically. Not so a short dipole like the LRS, doubly so owing to the use of resonant segments for dipole equalization. Horizontally, the transition depends on baffle width, frequency, room width, and your distance to the speaker. For a centered signal, you will always be listening in the near field where the speakers are less than half a wavelength apart and the distance between the speaker and the sidewall is less than a quarter wavelength. This will be true to a higher frequency in a small room and it will occur at any listening distance, because in those circumstances you have, acoustically speaking, an infinite baffle. Above the frequency at which that occurs, it depends on frequency, baffle width, and your distance to the speaker. So there are quite a few variables here, and the answer is perhaps best achieved by measuring at various distances. If you haven't seen them, Don Keele has written some excellent papers with a bearing on this -- they're available on his website.

As to whether I listen in the near field, judge for yourself, heh.