• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Magnepan LRS Speaker Review

Joined
Mar 13, 2020
Messages
51
Likes
16
If amir had done a better job setting these speakers properly he would have been blown away...but he did not. I have owned many speakers in my life, including the Dunlavy SCVs (please research them). I presently own Maggies 3.6s which are a freaking miracle in terms of reproducing music. Yes, it takes a long time to find the sweep spot and most Maggies will require sub augmentation. But please do not end a review of the LRS with a non-recommendation...it undermines the whole ASR effort. This was a blown review, pure and simple.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
28,599
Likes
76,392
Location
Seattle Area
Thread Starter #423
do you have specifics on how it was 'blown'??
Let's not encourage him to curse me more in one day! Let's ration it across a few days....
 
Joined
Sep 13, 2020
Messages
15
Likes
7
I would really appreciate if you did elaborate!
The crux of the matter is the design intent. For any dipole or bipole radiator, the ROOM IS PART OF THE DESIGNER'S INTENDED SOUND. By discarding the room sounds and measuring only the anechoic response, you discard almost half of the expected acoustic. That's why dipole and bipole radiating speakers come with specific instructions as to room placement. If the speakers are to be measured, both the distance from the speaker and the distance from the speaker to reflecting walls, ceilings, and floors are critical. To measure a panel speaker near field or in an anechoic environment is the equivalent of placing a "bookshelf" speaker in a corner and on the floor for measurement.

For any planar-magnetic or electrostatic panel, the width of the radiating surface is also an issue. Although Amirm uses multiple averaged measurements across the panel dimensions, this (again) ignores the designer's intent. Specific peaks and dips in the frequency response ARE inherent in the physical geometry of the panel, but those irregularities are also taken into account (by the designer) in the room placement. To measure the panel characteristics in isolation (ignoring the effect of the room, again) distorts the design intent of the speaker.

And finally, the distortion characteristics of the panel speaker have been measured in isolation. In the case of the LRS, yes, the distortion may rise precipitously above 10 watts, but the average listener uses the speaker at one or less watts. Want lower distortion at higher power levels? Buy bigger panels with more radiating area!

I concede that Amirm's measurements are accurate within their (gross) limitations, but I strongly dispute, due to the way that they were taken, that the measurements are at all useful in evaluating the actual sound of the speaker in situ. Any conclusion drawn from these measurements is a disservice to any reader trying to understand the speakers' sound. You're free to argue this if you wish, but the designer would almost certainly agree with me - the ROOM is an inherent part of the design and any attempt to measure the speaker in acoustic isolation is grossly misleading.
 

LDKTA

Active Member
Joined
Jun 8, 2019
Messages
165
Likes
185
These results are far worse than I expected but I cannot say I'm surprised. I've always found the Magnepan loudspeakers to be immensely flawed designs.
 

StefaanE

Active Member
Forum Donor
Joined
May 12, 2020
Messages
148
Likes
195
Location
Harlange, Luxembourg
... the ROOM is an inherent part of the design and any attempt to measure the speaker in acoustic isolation is grossly misleading.
Which ROOM?
 
Joined
Sep 13, 2020
Messages
15
Likes
7
And therein lies the question - Ideally, a room with symmetrical right and left halves, and one where a minimum of four or five feet of clearance is available from the back wall. But the speakers will ABSOLUTELY sound differently in different rooms (of course, this is true of ALL speakers, but far more so for bipole or dipole radiators).
 

Blumlein 88

Major Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
9,905
Likes
13,453
The crux of the matter is the design intent. For any dipole or bipole radiator, the ROOM IS PART OF THE DESIGNER'S INTENDED SOUND. By discarding the room sounds and measuring only the anechoic response, you discard almost half of the expected acoustic. That's why dipole and bipole radiating speakers come with specific instructions as to room placement. If the speakers are to be measured, both the distance from the speaker and the distance from the speaker to reflecting walls, ceilings, and floors are critical. To measure a panel speaker near field or in an anechoic environment is the equivalent of placing a "bookshelf" speaker in a corner and on the floor for measurement.

For any planar-magnetic or electrostatic panel, the width of the radiating surface is also an issue. Although Amirm uses multiple averaged measurements across the panel dimensions, this (again) ignores the designer's intent. Specific peaks and dips in the frequency response ARE inherent in the physical geometry of the panel, but those irregularities are also taken into account (by the designer) in the room placement. To measure the panel characteristics in isolation (ignoring the effect of the room, again) distorts the design intent of the speaker.

And finally, the distortion characteristics of the panel speaker have been measured in isolation. In the case of the LRS, yes, the distortion may rise precipitously above 10 watts, but the average listener uses the speaker at one or less watts. Want lower distortion at higher power levels? Buy bigger panels with more radiating area!

I concede that Amirm's measurements are accurate within their (gross) limitations, but I strongly dispute, due to the way that they were taken, that the measurements are at all useful in evaluating the actual sound of the speaker in situ. Any conclusion drawn from these measurements is a disservice to any reader trying to understand the speakers' sound. You're free to argue this if you wish, but the designer would almost certainly agree with me - the ROOM is an inherent part of the design and any attempt to measure the speaker in acoustic isolation is grossly misleading.
A load of malarkey born of wishful thinking in this post.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
28,599
Likes
76,392
Location
Seattle Area
Thread Starter #429
And therein lies the question - Ideally, a room with symmetrical right and left halves, and one where a minimum of four or five feet of clearance is available from the back wall.
Precisely the distance I had it from my back wall: 55 inches or 4.6 feet. The manual says this however: " Locate the speakers 2 feet or more in front of a wall." There is no mention of any symmetry requirement. Here is a sample image from Magnepan's own site for 30.7:



Not symmetrical at all.
 

Francis Vaughan

Senior Member
Forum Donor
Joined
Dec 6, 2018
Messages
352
Likes
1,576
Location
Adelaide Australia
Although Amirm uses multiple averaged measurements across the panel dimensio
Important point. No, this isn’t how Klippel works. In fact Klippel is capable of creating exactly what you demand. It solves the PDEs based upon the measurements taken and determined the actual radiating sound wave at each location in space. Of all the measurement systems around it is probably the only one capable of determining what a panel speaker is doing.
Where there is room for more work is in making use of the sound field projections. No doubt, a panel is a different beast and the manner in which it interacts with the room much more complicated than a box speaker.
There is a lot of talking past one another going on here. Everyone knew the first time a panel was measured fur was going to fly. It was a given from the outset that any dipole was not going to fit the standard mould. There is a lot happening here. Linkwitz wrote a considerable amount about this and the nature of how the speakers work in a room. He was no fool. Olive knew Linkwitz and his work, and was always full of praise for his efforts. I think he appreciated that there was much more to learn.
 
Joined
Sep 13, 2020
Messages
15
Likes
7
Precisely the distance I had it from my back wall: 55 inches or 4.6 feet. The manual says this however: " Locate the speakers 2 feet or more in front of a wall." There is no mention of any symmetry requirement. Here is a sample image from Magnepan's own site for 30.7:



Not symmetrical at all.
Marketing photos never are. Symmetry is an obvious requirement for any bipolar or dipolar speaker, and a pretty marketing photo does not change that. In fact, shame on you for even trying to muddy the water this way. You know better!
 
Joined
Sep 13, 2020
Messages
15
Likes
7
I'm done.

ASR strikes me as having a bunch of airhead followers of an outspoken guru. To give Amirm fair due, though, measurements and opinions are segregated and opinions are generally qualified. But that (important) distinction is consistently ignored by the average ASR poster, who gloms onto either the measurement or the opinion section and treats it as gospel. And don't try to argue - Amirm said it, I believe it, that settles it - Amen. Of course, the average ASR poster is quick to misunderstand the measurements, to quote Amirm out of context, and/or to put words in Amirm's mouth, but don't confuse the average poster with facts; their minds are made up.

My other objection to ASR is that the quantitive approach is emphasized to the point of worship while the qualitative approach is not only ignored but also denigrated, despised, and ridiculed. Foolishness.

To summarize - I respect Amirm - I respect the ASR website - I consider the measurements a valuable tool - but I consider the average ASR site follower to be a mindless zombie. That said, many ASR followers are far, far better and smarter than what I've described, but they don't seem to post as much. Come to think of it, keeping ones mouth shut in the midst of the madding crowd actually IS a smart thing to do.

Adios
 
Last edited:

Blumlein 88

Major Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
9,905
Likes
13,453
I'm done.

ASR strikes me as having a bunch of airhead followers of an outspoken guru. To give Amirm fair due, though, measurements and opinions are segregated and opinions are generally qualified. But that (important) distinction is consistently ignored by the average ASR poster, who gloms onto either the measurement or the opinion section and treats it as gospel. And don't try to argue - Amirm said it, I believe it, that settles it - Amen. Of course, the average ASR poster is quick to misunderstand the measurements, to quote Amirm out of context, and/or to put words in Amirm's mouth, but don't confuse the average poster with facts; their minds are made up.

My other objection to ASR is that the quantitive approach is emphasized to the point of worship while the qualitative approach is not only ignored but also denigrated, despised, and ridiculed. Foolishness.

To summarize - I respect Amirm - I respect the ASR website - I consider the measurements a valuable tool - but I consider the average ASR site follower to be a mindless zombie. That said, many ASR followers are far, far better and smarter than what I've described, but they don't seem to post as much. Come to think of it, keeping ones mouth shut in the midst of the madding crowd actually IS a smart thing to do.

Adios
Hasta la vista.
 

tuga

Major Contributor
Forum Donor
Joined
Feb 5, 2020
Messages
2,015
Likes
1,591
Location
Oxford, England
And here is our predicted in-room response:

View attachment 83611

There was no good way to draw the trend line given the large drop in bass response. But I tried anyway.

Speaker Distortion Measurements
At the original point I was measuring the speaker, the highs were very low and as such, I could not get the LRS up to 86 dB let alone 96 dB. Here are what I got anyway:




Distortion seems to be very much in control at higher frequencies.



Notice how rough the in-room response is where I measured the speaker.
Predicted In-Room Response is about perfect from 300Hz upwards. Does it take into consideration this particular speaker's (dipole) topology?
Distortion levels are also commendably low above 300Hz.
Finally actual in-room response sees the speaker making up for the roll-off below 300Hz but the overall response, particularly above 300Hz, becomes less smooth.
Letting aside the fact that the PIR measurement falls flat (highlighting their inneffectiveness with dipoles), could the in-room bump between 300 and 500Hz be the result of room interaction and/or inadequate positioning of either/both listener and speaker?

Interestingly @John Atkinson often comments that panel speakers are difficult to measure at nearfield distances yet the Klippel seems to have had no problems (although a CSD was not shown).

I'd love to see a measurement of a Quad.
 
Last edited:
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
28,599
Likes
76,392
Location
Seattle Area
Thread Starter #437
Oh, I thought I had post the CSD. Note that I have not tried to optimize its parameters:

Magnepan LRS Ribbon Speaker CSD waterfall Mesaurements.png


This is on the original acoustic axis which has much lower treble energy.
 

tuga

Major Contributor
Forum Donor
Joined
Feb 5, 2020
Messages
2,015
Likes
1,591
Location
Oxford, England
Oh, I thought I had post the CSD. Note that I have not tried to optimize its parameters:

View attachment 84037

This is on the original acoustic axis which has much lower treble energy.
Thanks.

I don't know how the speaker's built but it looks as though there's a slight delay below 200Hz.
Does it have a bass panel operating up to that frequency?
 
Top Bottom