Manger p1 loudspeaker Manufacturer's Comment

Manufacturer's Comment

I would like to thank Stereophile for this well-written and excellent review.

As a designer and manufacturer of a unique loudspeaker technology, it is satisfying to know that a magazine exists with a well-intentioned and competent editorial staff. In the case of our review, Herb Reichert perfectly describes his perception of the particular sound reproduction abilities of the Manger sound transducer, which is at the heart of all Manger loudspeakers. The research that led to the invention of the Manger sound transducer was all about a better transient response, by avoiding the energy storage of a piston-type driver. The notes from all musical instruments begin with a transient and this is exactly what the human ear perceives.

So why does a discrepancy exist between the measurement comments and the actual review? For decades, all loudspeaker measurements have been based on the steady state of piston-type drivers. I especially missed seeing a positive comment about the excellent step response of the Manger P1.

John Atkinson himself once wrote the following in an article for Stereophile, "There are not that many speakers that produce this good a step response . . . " [(footnote 1)] The comment regarding a missing impedance peak was another disappoint to me. In standard loudspeaker technical literature, like that written by Vance Dickason about loudspeaker design, you will discover the equalization of the resonance frequency of a driver, which is exactly what we are doing in the crossover of the P1. The result leads to a more constant impedance curve that represents a much easier load for an amplifier. JA's comment pointed out that there may be a mistake, since the usual peak was not present, which leads to a wrong impression for your readers.

In general, I had wished for a better explanation so that your readers could have a clearer understanding, especially in the case of measuring a different driver principle. This would have provided your readers with a much better perspective.—Daniela Manger, CEO and speaker designer Manger Audio


Footnote 1: See www.stereophile.com/content/measuring-loudspeakers-part-two-page-3. The step response I was discussing in that article was that of a Vandersteen loudspeaker.—John Atkinson
COMPANY INFO
Manger Audio
US distributor: MoFi Distribution
1811 W. Bryn Mawr Avenue
Chicago, IL 60660
(312) 738-5025
ARTICLE CONTENTS

COMMENTS
Bogolu Haranath's picture

Box loudspeakers which sound box-less :-) .........

Bogolu Haranath's picture

They should work well with a couple of powered subwoofers :-) .......

JRT's picture
Bogolu_Haranath wrote:

"Box loudspeakers which sound box-less..."

Boxless open baffle gradient designs can sound boxless if baffles are kept small enough. Well designed fully enclosed gradient loudspeakers (dipole, cardioid, etc.) can also sound boxless, depending very much on specifics of the design.

Opinions vary. Not everybody likes the same thing.

Bogolu Haranath's picture

Open baffle speakers like the Pure Audio Project speakers shown at the recent CAF 2019, covered by HR :-) ......

JRT's picture

https://www.linkwitzlab.com/LX521/Description.htm

https://www.madisoundspeakerstore.com/4-way-speaker-kits/lx521-linkwitz-lab-open-baffle-4-way-kit/

https://www.magiclx521.com/epages/17940394.sf/en_GB/?ObjectPath=/Shops/17940394/Products/PoBox6

https://www.hairballaudio.com/catalog/linkwitz-asp4

https://www.ati-amp.com/AT52XNC.php

Bogolu Haranath's picture

Another one is Spacial Audio Sapphire open baffle speakers shown at the CAF 2019 :-) ......

JRT's picture

Note that the dip at 1600_Hz is the result of destructive interference within the Manger MSW driver, and is not something that anyone should try to fix with simple equalization, as that will just result in excessively high input signal and elevated distortion.

Bogolu Haranath's picture

That 'dip' is a very narrow bandwidth dip ........ Should not cause any significant audible problem :-) .......

Kal Rubinson's picture

The "dip" itself may be narrow but it is at the bottom of a broader "bowl" in the FR.

Bogolu Haranath's picture

True ..... That dip is located in the 'bowl' that extends from approx. 1.2 kHz to approx. 3 Khz ....... That bowl is located in the so called famous BBC dip ...... although, the BBC dip usually extends from 1 kHz to 4 kHz ..... That BBC dip is intentionally engineered in some famous loudspeakers ...... That BBC dip can be as much as -5 db ....... Here it is not that much pronounced ........ Anyway, HR did not mention anything about it and didn't seem to be bothered by it :-) ........

music or sound's picture

is that new form of editing comment: when I was clicking on save my comments disappeared!
so again

That dip is existing in MSW drivers in all their speakers for at least 2 decades. I experimented with a MSW using a vibration absorbing gel the measured dip got greatly reduced and lower highs became much more present and alive. So that dip is audible!

JRT's picture

Yes the defect is built into the design of the Manger MSW( Manger Schall Wandler) , and that portion of the MSW has not changed much. I think the only thing that Josef W. Manger did change significantly was the magnet structure, changed from ferrite to neodymium. But he did not much change the pad that connects the rear center of the diaphragm to the "Hochton-Reflexionsdämpfer", the tweeter reflection damper, the material that damps cavity resonance in the "Polkern", the pole piece. Something different is needed there, perhaps different geometry as well as different material, to better damp and terminate the structure borne sound at the center of the diaphragm, so that it does not reflect back outward without more damping.

The source of interference is the structure borne sound within the diaphragm, propagating through the diaphragm from the voicecoil former toward the center and then back outward to the voicecoil former, interfering at the node where the voicecoil former joins with the diaphragm. At 1600_Hz the reflected return arrives in antiphase only slightly damped, and destructively interferes in the sum there.

Did you try drum head damping material, something like Moongel?
https://drumheadauthority.com/product/moongel-damper-pads/

Or perhaps drum rings?
https://drumheadauthority.com/product/o-rings/

music or sound's picture

Yes exactly, there is a thread https://www.diyaudio.com/forums/full-range/208995-manger-msw-moongel.html

JRT's picture

Thank you very much for that link.

Bogolu Haranath's picture

Wonder whether we can use those Moongel pads on CDs and vinyl records? ....... Then those CDs could sound like vinyl records and those vinyl records could sound like CDs ........ Just a thought :-) ......

Herb Reichert's picture

to clean my styli

hr

Bogolu Haranath's picture

HR could review one of the Cube Audio speakers (preferably, the Nenuphar), and tell us how they compare with the Manger :-) ........

Bogolu Haranath's picture

HR could also review the new KLH Audio Ultimate One headphones with Beryllium drivers, $300 :-) .......

Bogolu Haranath's picture

BTW ...... There is always room for Moongel(lo) :-) ........

JRT's picture

I bought two pairs of Manger MSW drivers from André Perreault when he was proprietor of e-speakers.com (he sold Raven, Manger, PHL, TAD pro drivers, etc.) approximately 1.5 decades ago. Sadly, cancer took André in 2015, and e-speakers is now defunct.

His e-speakers.com business was his sideline.
https://www.imdb.com/name/nm0674550/

Bogolu Haranath's picture

Did you hear any of the current production Manger speakers? ....... TAS also reviewed the Manger p1 recently ....... Also, Twittering Machines reviewed the self-powered version of the same speakers s1, recently ..... Both those reviews are available online ........ Both those reviewers didn't seem to be bothered by any problems in the lower treble region :-) ......

JRT's picture

Joachim Gerhard's Audio Physic Medea was well received back around the turn of the century, but was also rather expensive, so I don't think it sold in large numbers (but I do not know the sales figures and could be wrong).

The Manger Zerobox 103 and 109 were also well received by reviewers.

My point being that loudspeakers utilizing the MSW have been well received by some reviewers, and not just recently, but also earlier.

Not everybody likes them. Narrow directivity at higher frequencies has been an ongoing issue. Off axis response should be similar to on axis response, especially in directions of first reflection.

Bogolu Haranath's picture

BTW ...... There is also another -5 db dip from 700 Hz to 1 kHz :-) ......

JRT's picture

I would hope that most anyone reading the measurements with any significant depth of understanding would have a clear sense of the obvious in looking at the frequency response. But they might not understand the underlying mechanism causing the problem, and might exacerbate the problem with inappropriately applied equalization. It is OK to pull down the peaks a little, but they should not try to lift areas of significant destructive interference.

Bogolu Haranath's picture

Agreed ....... They should listen first before applying any kind of EQ ........ Like Confucius said, 'measurements alone won't tell the whole story' :-) .......

Archimago's picture

But there's nothing wrong with pulling down the other frequencies a few dB with DSP. :-)

I would be curious to see what the FR looks like at the listening position though.

I see the Manufacturer Response. Sure, it's great that the step response looks good and the impedance is relatively smooth (although an important portion dips down to 3Ω around 250Hz). But the frequency response is still more important than these other factors in terms of audibility. As such, I think JA is right not to accentuate these secondary factors.

Good looking speakers though.

JRT's picture
Archimago wrote:

"Right... Don't pull up the dip. But there's nothing wrong with pulling down the other frequencies a few dB with DSP."

Note that the depicted response includes significant smoothing.

That smoothing is used because it makes the response easier to read, and it is pretty well correlated to audibility of deviations within the response, but that smoothing is not well correlated to suitable EQ. Rather a different smoothing is better for developing the forcing function.

You cannot lift the center of a destructive interference full cancellation null. But phase sum varies more further away from the center of that null. So throwing more signal voltage into correcting the null can narrow the width of the null, but cannot lift the center of a full cancellation. Partial cancellation can be lifted, but it depends on "partial", and comes at the expense of more signal voltage than might seem necessary by cursory look at response. If the resulting forcing function has big peaks, a very much higher output amplifier is needed to avoid clipping, and nonlinear dynamic compression from voicecoil heating becomes a much bigger problem.

So rather than trying to lift deep destructive interference nulls, it is better to pull down peaks.

Fixing an interference null requires fixing the acoustic interference, not the input signal. If that cannot be adequately fixed, move on to something else.

John Atkinson's picture
JRT wrote:
Note that the depicted response includes significant smoothing.

There's no smoothing in the response graphs in the Stereophile review.

JRT wrote:
Fixing an interference null requires fixing the acoustic interference, not the input signal.

Agreed. You're just pumping more energy that will still cancel at the measurement position, which will be very audible elsewhere in the room. I was at a lecture given by the late Michael Gerzon in Vienna in 1992 where he discussed this problem. He drew a straight horizontal line on the whiteboard. "You all know what that is," Michael said. "It's the target response for room correction. And you should all also know that it sounds terrible!" :-)

John Atkinson
Technical Editor, Stereophile

Bogolu Haranath's picture

EQ/DSP/subwoofers 'modify' the signal, not just uniformly increase/decrease the signal ....... Am I right? :-) .........

Bogolu Haranath's picture

It would be interesting to see the FR measurements of Manger s1, which is the self-powered version of p1 ..... s1, has several adjustments in the back panel :-) ........

JRT's picture
JA1 wrote:

There's no smoothing in the response graphs in the Stereophile review.

Without the usual smoothing of frequency response, I would expect to see something very coarse like the unsmoothed red response rather than like the smoothed blue response shown in the following graphic.

Bogolu Haranath's picture

What loudspeakers are those in your graph? ....... Who did those measurements? ...... What equipment did they use for those measurements? :-) .......

John Atkinson's picture
JRT wrote:
Without the usual smoothing of frequency response, I would expect to see something very coarse like the unsmoothed red response rather than like the smoothed blue response shown in the following graphic.

I window the measured impulse response so the FFT-derived frequency response doesn't show the effect of boundary reflections.

John Atkinson
Technical Editor, Stereophile

Bogolu Haranath's picture

Anyway, your loudspeaker 'smoothed' graph shows that, they have a FR on a downward slope, starting from 90 Hz and reaching -15 db at 20 kHz ...... Kinda nice for skiing :-) ........

JHL's picture

The present obsession with FR has become one of audio's largest cases of sighted bias. I hope Sterophile does not succumb to it. While it takes a book to explain why, within reason it's simply not fundamental to good sound.

jmsent's picture

Looking at the impedance plot you can see a pretty alarming series of small peaks and dips that are indicative of chaotic behavior within the driver itself. This kind of an impedance plot on a standard cone or dome driver would be considered a sign of rather poor design. Such "bumps" are usually an indication of resonances and edge reflections in the driver diaphragm. And that ,of course, is also confirmed rather well by the very choppy response curves. Whatever secondary benefits are being claimed for this driver design, the sure seem to come at the expense of some very basic performance parameters. I'm sure they do indeed impart a "unique tonal character" to the complete loudspeaker system. And I guess, that's the goal in the first place.

JRT's picture

There is no perfect solution to the complex problem. Everything comes with tradeoff compromises. That is what makes the pursuit of a better solution that much more interesting.

Compared to two way coaxial, the Manger MSW does not suffer much diffraction related interference.

In the coax, the tweeter radiates through a large undamped cavity resonance formed by midrange cone diaphragm. That outer cone forms an imperfect wave guide shaped more for structural support of the diaphragm than smooth directivity for the tweeter. And that waveguide moves, excurses with inverse square function with respect to frequency. The tweeter is going to see edge diffraction where it meets the cone, and that edge diffraction will vary with cone movement.

Yet the little KEF LS50 has a pretty good reputation within its significant limitations.

Ortofan's picture

... for about the same price as the Manger (depending upon finish), one could choose the KEF Reference 5.
Their overall frequency response is much smoother and JA1 commented that they "gave me all I need for musical and sonic satisfaction."
https://www.stereophile.com/content/kef-reference-5-loudspeaker

Bogolu Haranath's picture

JA1 was being polite and politically correct ........ KEF Reference 5 roll-off from 3 kHz and are -7 db down at 20 kHz ...... See his in-room FR ........ JA1 actually likes Revel Salon2 ....... Just ask him :-) ......

JHL's picture

Much of the trend favoring coaxial speakers may assume that axially-coincident drivers produce perfect balloons of sound, and that perfect balloons of sound produce fundamentally superior audio. The thought then is that the tweeter-over-woofer configuration is inherently perfected, or at least fundamentally superior.

As you point out, it's not. Important points like distortion, inter-modulation, directivity, diffraction, and simple level - which involves size versus distortion - enter in. Thanks for that pertinent information.

Also confounding the pro-coax belief is that while in reality such speakers produce a polar consistency they needn't necessarily produce a polar *uniformity*. Get the transfer function between drivers wrong and they produce a ping pong ball-in-a-donut pattern of treble over midrange.

I don't think the Manger sounds good strictly because it's a coincident speaker. If it sounds good it does so largely because as a single driver it has good time and phase behaviors, which means it may actually *deviate* from a coincident, co-axial speaker a very great deal.

Bogolu Haranath's picture

Passive KEF LS-50s are not time-coincident ...... however, active KEF LSX (reviewed by Stereophile) are DSP controlled time-coincident ....... Most likely, the active KEF LS-50 wireless and active KEF LS-50 Nocturnes, are also DSP controlled time-coincident :-) .......

Bogolu Haranath's picture

Whizzer cone speakers, which are crossover-less, (like the Cube Audio and Voxativ), are also time-coincident, if properly designed :-) .......

georgehifi's picture

I vaguely remember, kits of these, when they first made an appearance some decades ago, hope it happens, now that they seem to be much better sorted this time around

Cheers George

music or sound's picture

Manger does not sell their Driver for diy anymore

music or sound's picture

Bending wave have the advantage of not trying to be pistonic i.e accelerating an infinitively stiff membrane (not quite possible) but also makes modeling them much more complex (like modeling a violin).
Significant advantages of a single driver covering the low mid to all the highs are that no crossover is required in that region where it is most audible, coming from a single area (avoiding interference) and the lack of intermodulation distortion derived from a woofer low frequency movement superimposed on mids (Doppler like effects) as unavoidable in woofer/mid driver crossed over higher.

tonykaz's picture

... with more bass and dynamics"

I'd have to reflect for a moment and conclude that we all now know just what these things sound like.

Thanks for going to all that trouble.

But...

I'd like to learn what the same Loudspeaker in Active ( about $25,000 ) does, I'll guess plenty considering what I've heard from Genelec and a few others that have 500 Watts built in to each loudspeaker. ( down to 30hz with gazoons full of dynamic Range to scare an innocent Couch Potato into reaching for the Nitroglycerins )

The Quad comparison comment probably brings this Transducer System into accurate perspective: a great system for the mid 1980s Market place, nice engineering, nice-solid construction, living room friendly. Can we put a flowering Plant on it's top ?

Tony bouncing around the frozen North

ps. I'm feeling a bit negative from slushy puddles and freezing cold. I've owned Quad 63s w/ Subs., sold em and never missed em, evahhhhhhh!

JRT's picture

If and when you get to somewhere near Grantham, New Hampshire, perhaps you might try to find time to meet up with Dr. Sheldon D. Stokes, SDS Labs (quadesl.com). Sheldon rebuilds Quad ESLs as a labor-of-love sideline. His website shows that he has a couple of pairs of Quad ESL-63 currently available for sale for $3k and $3.2k.

Just because you have not missed them, does not mean they are not worthwhile loudspeakers. With frank comment risking offense, and with no offense intended, I would suggest that perhaps your hearing perception has changed in recent decades, losing some sensitivity at both ends of the spectrum, and might now be more focused on perception of midrange frequencies, which the Quad ESL-63 are very good at reproducing in the sweetspot listening region.

tonykaz's picture

My ears & hearing are over 8 db down at both ends, my upper droop starts at 8 kHz.

I have Eq. on my headphone rig and room tuning to try to compensate in an approximate manner.

I've had University of Michigan Audiologists assistance in all this, it's a deteriorating condition.

On Quads rebuilding and tuning: I'm aware of Dr.Stokes's work and have applauded his efforts, I've even passed him along ( referred him to my 1980s Quad Customers who still own Quads ).

However,

I'm a dynamic driver type person. I'm also a big Mono SS Amps person and a tube rolling pre-amp sort. I've learned that Mono amps are always better. Even Better yet are Mono Amps driving individual Drivers ( as in Active Loudspeakers ) . So, for me, Active dynamic loudspeakers rule the roost, they get as close to headphone quality as loudspeakers get.

Tony in Venice ( I'm not certain where I am just now )

ps. thanks for taking the time to write, dam good tip on Quads, thanks!

dial's picture

"Manger does not sell their Driver for diy anymore" and that's sad. Focal's done the same, except for some medium and tweeters. In fact, every loudspeaker has its flaws and his qualities, and we wish more of the second.
I once had a pair of boxes and after trying to put car audio in (terrible sound), I bought 2 med-woofers and two highs and it sounded very good (to my ears).

jeffhenning's picture

One of the options you can get with the Mangers is their Holoprofile. It's used to divert part of the radiation of the Manger driver off to the side.

If you delve into their research documentation (if it's still available) were laser interferometry images that precisely showed where the each frequency was radiated on the driver. Starting from center, the highest frequencies emanated there and the lower the frequency, the further toward the edge it was produced in a concentric fashion. By the time you hit about 500Hz, the driver was acting as a piston.

The problem, though, with that concentric radiation means that mid-treble frequencies are produced in a ring that's large enough to cause off-axis lobing. Not a huge problem vertically, but a big one horizontally. Not being in the sweet spot could really change your perception of the sound.

If you, though, divert the upper frequencies on the outside of the driver so that they don't arrive at your ear, that comb filtering is eliminated.

Here's a link:

https://mangeraudio.com/en/systems/product/accessories

volvic's picture

On a cold windy day in NYC, Herb Reichert's reviews are like a warm summer breeze. So enjoy reading his reviews. BTW Herb, what happened to the Linn LP12?

Herb Reichert's picture

is sitting right next to me now - begging for a new (better) tonearm.

I haven't made a choice yet.

(Thank you I am honored you enjoy my prattles)

peace and holiday cheer,

herb

Bogolu Haranath's picture

May be HR could review the MAG-LEV turntable? :-) .......

tnargs's picture

Herb has fallen for the common misconception that speakers sound like the sound of their driver material.

This idea is driven by auto-suggestion. You start 'hearing' it, driven by the logic of it. Paper-edgy, metal-ringy, plastic-dully.

Try doing it blind (not even knowing if the speakers on audition are all the same driver material, or not). That will change the opinion very quickly.

The Manger's frequency response errors and beaminess explain the sounds you wanted to attribute to plastic.

cheers

ChrisS's picture

...the effect of "auto-suggestion" lasts?

A minute? An hour? A life time?

Are you a Miami Dolphins fan, despite their stats?

Can you "auto-suggest" to everyone that the Ford F-150 is the best truck in the world?

No one does anything "blind".

tnargs's picture

Autosuggestion is just a word for the process where we convince ourselves of things. Autosuggestion is a psychological technique related to the placebo effect. It is a form of self-induced suggestion in which individuals guide their own thoughts, feelings, or behavior.

In the context that I used it, the individual will have their own sense of what paper sounds like when they brush a hand against it, fold it, handle it. This guides the person's perception of what they hear when they know the driver is made of paper. Or metal, or plastic.

There are common themes, for example, the sound of paper or metal being tapped or handled is pretty common, so you might find a group of audiophiles knowing a driver is metal and all agreeing that it has a faintly metallic quality to the sound, but this perception does not persist if they are 'blinded' to the knowledge of the driver material.

So, commonality exists, but there is no universality to it. A reviewer might suggest (or simple inspection might reveal) that a loudspeaker is very solidly built, but one person might autosuggest themselves into hearing solidity as lots of bass, and another might end up 'hearing' it as an absence of boominess. The point is that autosuggestion dominates when one is engaged in sighted listening.

How long does it last? Could be a lifetime, such as Fremer on what digitized music 'sounds like' (tripped himself up lately on Abbey Road, haha, saw that), or could be gone in the next minute, if the individual changes his self-guidance. For example, if someone reading this mini-essay is persuaded by it, both at the conscious and subconscious levels, then he or she might never again autosuggest a material-based sonic overlay on the sound of speakers again. Or there might be resistance, based on something deeper like a belief that you never learn anything from internet comments, or a greater respect for Reichert as a writer, so there is no change. Or one might flip-flop over time: convinced by me for the short term, but then reads something by another reviewer that reinforces the myth and it all comes back. So, there is no answer to how long it 'lasts'; it is an ongoing script that only you can turn off.

I agree, no one does anything 'blind'. But the lessons from formal, statistically-analyzed blind tests deserve serious consideration (as the best source of information about the actual sound waves as perceived by listeners separately from autosuggestion effects), instead of serious attempts to discredit just because they contradict what we hear from sighted listening. (Cue Stereophile staff in unison)

cheers

Bogolu Haranath's picture

May be something similar to 'confirmation bias'? :-) ........

ChrisS's picture

...inappropriate for audio reviewing. This discussion has been more than adequately covered on this forum and by John Atkinson. It's not going to happen.

The only tests that really matter are the ones we conduct with our own ears with our own equipment in our own listening environments with our own music. And ultimately, with our own beliefs.

Stereophile does an excellent job telling us about items to check out and considerations and issues to ponder.

AJ's picture

Not according to the founder of Stereophile https://www.stereophile.com/asweseeit/1107awsi/index.html

"Remember those loudspeaker shoot-outs we used to have during our annual writer gatherings in Santa Fe? The frequent occasions when various reviewers would repeatedly choose the same loudspeaker as their favorite (or least-favorite) model? That was all the proof needed that [blind] testing does work, aside from the fact that it's (still) the only honest kind. It also suggested that simple ear training, with DBT confirmation, could have built the kind of listening confidence among talented reviewers that might have made a world of difference in the outcome of high-end audio."

Quote:

The only tests that really matter are the ones we conduct with our own ears

..and eyes and mismatched volume and...
As JGH also said:
"As far as the real world is concerned, high-end audio lost its credibility during the 1980s, when it flatly refused to submit to the kind of basic honesty controls (double-blind testing, for example) that had legitimized every other serious scientific endeavor since Pascal. [This refusal] is a source of endless derisive amusement among rational people and of perpetual embarrassment for me, because I am associated by so many people with the mess my disciples made of spreading my gospel."

Stereophiles founder was quite aware.

ChrisS's picture

...reviewing for Stereophile.

Check with John Atkinson.

JA and Michsel Fremer were challenged years ago to test their listening skills by doing DBT's, and after proving their success at identifying the test components, neither they nor anyone else have ever used DBT for audio reviewing.

ChrisS's picture

...DBT is still an inappropriate tool for audio reviewing.

Do a college-level course on research design and testing.

Please.

X