... what the press says

"... The Swing forms a completely balanced mid-tone/treble range unit with rarely to be heard transparency and plasticity. There is absolutely no call for any sort of "exotic bonus"…"
Stereo 10/02


"... The depiction is lso quite large, differentiated and leads you to suppose that the loudspeaker is larger. But it is the musicality that is convincing. The music flows, flatters and bewitches…. This is a friend for life for anyone looking for relaxed and enjoyable listening pleasure."
Hörerlebnis No. 40


" A listening test with a Manger sound transducer is certainly one of the most illuminating experiences for even the most hardened hi-fi tester, as the system reveals the faults of conventional sound transducers with brutal honesty. It was simply breathtaking the way that the Swing, as if it was the most natural thing in the world, reproduced even the finest triangle notes."
Stereoplay 2/2002


"...If you are seriously interested in speaker design and the possibilities implicit in total coherence, you must listen to this speaker. If you can afterwards go back to one with even a hint of isolated tweeter, I’ll be surprised. The Manger shows us things we need to know, and it offers a remarkable musical experience....”
the absolute sound 9/2001


"High efficiency factor, tonal broad-band capacity together with enormous level stability are the self-evident qualities of the Zerobox 103. But the unbelievable impulse fidelity and precision of depiction of the Manger sound transducer make the Zerobox 103 an excellent transducer that offers emotion and authenticity in abundance."
Image HiFi 4/2001

"... And then comes the time when: This transducer can simply do more in subranges. And once you have become accustomed to the complete lack of the spectacular and overlap effects, then you are left with only one thing: exactly what is stored on a sound recording."

Stereo 11/2000


"... With enjoyable composure I experienced the conversation and the singing in the great ballroom, the voices were so present, as if the performers were standing in front of me..."

Audiophile 4/2000


"... the Manger sound transducer – an acoustic star..."

Kopfhörer 12/99


"... It is simply spectacular how unspectacular the Manger sound transducer reproduces music..."

Audio 11/99


"... The Manger transducer is a brilliant construction without a doubt..."

Hifi&Records 4/99


"... the secret of the Manger sound transducer: Impulse-true. In the rather slowly advancing technology of loudspeaker design, the Manger transducer represents a large step forwards..."

Studio Post Pro 2/99


"... entry ticket to the fascinating experience of the absolutely finest audiophile systems..."

Stereo 2/97


"... Thanks to the revolutionary sound transducer system true progress in loudspeaker design. Sets acoustic standards with regard to homogeneity and naturalness of reproduction..."

Sound&Vision 1/97


"... Josef Manger's aim of achieving the most time-true representation of acoustic signals as possible has proved to be more than just plain theory, because as the only representative in the 'Absolute Top Class I, Section Speaker Kits" the Zerobox 107 achieved a top position ..."

Stereoplay 1/96


"... The result amazed even the experts at the first presentations. The ear no longer hears any annoying noises, but what should be at the forefront when listening – the sounds of the music. ..."

SZ 12/95


"... No other loudspeaker sounds so little like hi-fi ..."

Brief test Audio Physic 'Medea II'


"... the longer you listen to the Manger loudspeakers, the clearer its most important characteristic is honesty..."

FAZ 1/96


"... whereas other loudspeakers often put themselves in the limelight, nothing spectacular reveals itself to the ears of the listener, only the music is there – simply room-filling and natural. ..."

FAZ 9/95


"... I am totally convinced that this loudspeaker represents a quantum leap in sound reproduction. This is certainly what the future holds unless the leading specialist magazines miss the boat."

Reader's letter in Audio 2/95


"... I found that the chassis were very sound-neutral and that no listening fatigue occurred. The opposite was the case..."

Stereoplay 2/95


"... I have not enjoyed listening to music with so much pleasure for a very long time ..."
Test report Audio Physic 'Medea' with Manger sound transducer

HiFiExklusiv 5/93


"... we took many hours for the listening test. We were delighted from beginning to end, because this system never plays music in a nerve-racking way, it is decidedly fast and fans out timbres in a highly differentiated way."
Test report Are Mo 'Symbiose' with Manger sound transducer

Stereo 12/94


"... the inventive Franconian has been proved correct in his deliberations on the temporal behaviour of sound transducers. The theory can be understood only by a handful of audiophiles, but more and more are hearing quite clearly what a great gift he has given us with his invention."

Brief test Audio Physic 'Medea II
HiFiExklusiv 8/94


"... Without a doubt the Medea owes its particular sound qualities to the unique properties of the Manger sound transducer."

Brief test Audio Physic 'Medea II'
HiFiExklusiv 8/94


"... All of the listeners were overwhelmed by the way the Manger transducer conjured up a breathtakingly exact spatiality, which the conventional comparison loudspeakers, irrespective of whether flat-core or direct radiator, could only at most bring to a limited extent."
Audiothentic 'Femto' with Manger sound transducer

Stereoplay 5/93


"... I can really only underline the Manger slogan 'Precision in sound'. This is truly fatigue-free and high-resolution, impulse-true listening."

Interview Friedrich Thein – Thein Recording Mobile
Studiomagazin 4/93


"... At almost 1,000 Marks the Manger transducer is not exactly cheap, but it gets you closer to the ideal sound transducer than ever before."

Klang & Ton 4/93


"... If you have the chance to test this loudspeaker, then do it."


English translation of offprint from Issue 1/97 of Sound & Vision magazine (Switzerland)

Exactly on time - Manger "Zerobox 107"
The Manger bending wave transducer is certainly one of the most fascinating transducers. Until
now it has only been used in high-quality studio monitors and outrageously expensive high-end
products. With the "Zerobox 107" Manger is now presenting for the first time a complete finished
loudspeaker, to allow a wider circle of music lovers to enjoy this exclusive transducer thanks to a
helpful price policy.
The starting point for the invention of Josef W. Manger was the recognition at the end of the 60's that loudspeakers with
practically identical amplitude behaviour sound completely different, and in spite of high linearity until now tend towards
aggressiveness and unwanted noisiness. In his search for the causes of this peculiar phenomenon he came across the
transient of the loudspeakers, which he nowadays regards as the main factor for the tonal limitation of conventional
designs. He was backed up in this by audiological studies at the University of Würzburg, which demonstrated that the
human sense of hearing is capable of localising noise occurrences within the first 10 milliseconds in the brain-stem,
whereas the noise character is not determined in the cerebrum until a latency period of 80 milliseconds. Apparently this
capability was of extreme importance in human evolution, as man benefites from this ability to perceive the location of a
potential danger source very quickly, even before he had to decide whether the "localised" noise represented an actual
danger for him. In the case of loudspeakers the findings summarised here in the briefest form mean that due to the
repititions of short-term overshoots, the attention of the listener is unconsciously and permanently directed to the
location of the loudspeaker, whereas the "hearing" of the sound body with a time delay suggests a different image. As
time progresses this ambivalent information content is felt by human perception as time progresses as annoying and
tiring. The Manger transducer reveals a perfect time behaviour embedded in a large acoustic baffle. However with only
one single transducer in the loudspeaker housing a typical pressure drop to the half of the original value occurs as soon
as the acoustic wavelength matches the housing width. With the two transducers fitted laterally on the Zerobox 107 this
effect is compensated by generating a large sound baffle in an acoustic way. How this system works exactly is
illustrated by the measured step response which matches almost perfectly the natural pressure compensation of the air.
The bending wave transducer finds its limits in the low bass range, which is why the Zerobox 107 is supplemented
below the cutoff frequency of 150 Hertz by two dynamic 20 cm bass chassis manufactured by Vifa to Manger
specifications. The measurement of the amplitude behaviour shows that in spite of the enclosed housing a relatively low
limit frequency of 45 Hertz is achieved. Measured on the axis the Manger transducer reveals an exemplary linear
progression. When the speaker is turned through 30° a narrow-band, but distinctive sound-pressure dip at 9 kHz occurs,
so that the loudspeaker should be directed as far as possible towards the location of listening. The extremely fast decay
of the transducer in the treble range is also impressive.
That a truly innovative technical development has been found also in the sound result was underscored by the Zerobox
in the listening test. The most striking element is its capacity to represent sound structures and instruments in an
absolutely unusual naturalness. The loudspeaker achieves the credible illusion of actually participating in the musical
event. Whether this is actually attributable to the lack of transient phenomena can never really be determined
subjectively, but the gentle and smooth mellifluousness and the exceptional purity with which the Manger loudspeaker is
capable of reproducing human vocals makes this supposition seem credible. Unnatural hissing is suddenly absent and
even in forte passages not a trace of noisiness could be determined. And the Manger loudspeaker does not achieve its
warmth of sound and smoothness by a loss of brilliance. Strings are reproduced with the same love of detail and
definition, and harmony-rich instruments are not restricted in their richness of sound timbre. In addition the Zerobox 107
never forces you to listen at high volume. Even at low volumes the complete sound content of a recording is present.
The exact spatial representation makes it easy for the listener to recognise "the crimes" committed by some recording
studios and the noise trails of poor reverb units, which also confirms the honesty and precision of these loudspeakers.
The balance and homogeneity of the Zerobox 107 is a further criterion which listeners will not want to miss after
listening for a longer period. The bass blends perfectly into the sound picture with its admittedly discrete and slim, but
flawless and differentiated, playing.
Summary
The Manger transducer is not only the result of decades-long research work with a great deal of expenditure and
passion, but the application presented by the Zerobox 107 offers true progress in loudspeaker reproduction. And even if
the technical explanation might appear to be somewhat difficult to comprehend, the sound result demonstrates that here
for the first time a transducer system is available setting new benchmarks regarding homogeneity and naturalness of the
reproduction with speaker dimensions to suit a domestic environment.

Thanks to a revolutionary transducer system real progress has been made in loudspeaker construction. Sets new
benchmarks regarding homogeneity and naturalness of reproduction.
Sound excellent
Handling very good
Workmanship very good
Price/Performance very good - excellent
Evaluation grades: unsatisfactory, satisfactory, good, very good, excellent. Related to the relevant price class.
Manger transducer
The Manger transducer is the result of development work carried out over a period of more than 20 years by Josef W.
Manger. The aim was to design a sound transducer, which would enable the exact-time radiation of all frequencies and
to do this without the disturbing transient phenomena caused by dynamic transducers operating on the mass-and-spring
principle. Due to the moving mass and the restoring forces of the spring tensioning conventional dynamic transducers
produce more or less pronounced short-term overshoots, which are not present in the original input signal, and which
are perceived in human hearing, as has been proved by recent audiological findings, as localisation information. These
"transient noises" can demonstrably lead to threshold shifts and fatigue, as the hearing is being constantly fed - directly
from the loudspeaker - with additional "localisation information", which it can correlate neither with the stereo
representation nor with the experience of a natural sound impression.
To achieve his goal of an exact-time and vibration-free transducer Manger made use of the bending wave phenomenon,
where the diaphragm, the stiffness of which gradually reduces from the centre to the tensioning edges, is excited
centrally. The applied signal is deconstructed into its individual spectra, and all sections are radiated at exactly the same
time, as illustrated by the sketch. The theoretical deliberations in 1978 of Dr. Manfred Heckl, Professor for Acoustics at
the Technical University of Berlin, were the first to establish the absolute certainty that the "Manger Concept" operated
without any transient phenomenon whatsoever. But a great number of manufacturing obstacles had to be overcome
before the concept reached series production. Nowadays the technical - and also tonal - quality of the Manger
transducer can be confirmed, and this development can certainly be regarded as revolutionary. The wide-band
behaviour of this transducer from 85 Hz to over 30 kHz is also impressive with a maximum sound pressure of 110 dB.
The rise time according to the manufacturer is 14 microseconds, which is clearly below the CD standard value of
22.7µs.
Summary
The absolutely perfect transducer acting as a single point sound source will not become available in the near future.
In addition we will also have to live with the loudspeaker being the greatest source of error in the reproduction chain. But
the presented options offer partial solutions, which have been elaborated with a great deal of imagination and, in the
interim, have also been tried-and-tested, and the results of this do however differ greatly in their sound performance.
The art of the clever loudspeaker designer remains what it has always been, namely to find the best sound compromise
among all decisive criteria and the possibilities offered by the transducer.
Insert:
Measured values
Elac 215 4p II
Exemplary linear amplitude behaviour with slight bass boosting. The effect of the switch settings can be seen in the
diagram. The Elac 215 4p II displays excellent omnidirectional behaviour. The two middle curves (measured on axis and
at 30°) cover one another practically completely in the treble range. The decay spectrum reveals only minimum
resonances.
Odeon Theatre
The amplitude behaviour reveals certain irregularities of the treble horn. A relatively marked sound pressure dip can be
seen in the area of the cutoff frequency of 1.4 kHz. The horn has a rapid and practically resonance-free decay.
Manger Zerobox 107
The measurement of the Zerobox 107 turned through 30° from the axis reveals a narrow-band frequency cancellation.
Otherwise only excellent measured results. Absolutely uncritical impedance, good efficiency factor at 90 dB, almost
ideal step response as well as a remarkably rapid decay of the transducer above 2 kHz.
Martin Logan CLS IIz
The acoustic short circuit in the bass range below 150 Hz can be easily seen in the amplitude behaviour. Heavy,
capacitive impedance with a minimum of 1.5 Ohms at 15 kHz. The decay spectrum in the middle range is also not
resonance-free.

Special imprint from image hifi 4/01
Manger Zerobox 103

by Udo Ratai
It is no exaggeration that the bending wave transducer developed by Josef W. Manger more than 20 years ago is
nowadays even more than in the past one of the most fascinating sound transducers. The largest passive pedestal
loudspeaker from the family company that has been managed by Daniela Manger for many years uses no less
than three of these continuously optimized systems. Using the optionally available adhesive "Holoprofiles", it is
claimed that the existing fantastic precision in depiction can be experienced at an even further auditory level.
It would fill volumes to provide an insight into the twenty years' history of the Manger sound transducer and the
lifework of its creative genius Josef W. Manger. And the examination of the scientific aspects of this legendary
transducer would necessitate just as detailed a description of the physics and acoustics, and that would also be
well beyond the remit of this report. There is an important reason why I only touch on the edges of this aspect:
the Zerobox 103 has captivated me to such an extent that it would be an injustice to dilute the joy and fascination
experienced with this speaker with an unavoidably dry and theoretical description.
Therefore I have decided to report on the chronology of events and I hope this is not too weighed down by
technical ballast. At the beginning of April we were paid a visit in Gröbenzell by Daniela Manger, who has been
continuing the work of her father in the family-owned business for over ten years. In addition to the Zerobox
103, the largest passive loudspeaker in the range, the Diploma Engineer had also brought along a CD. This had
been compiled by Manger at the request of many of its customers with pieces of music enjoying a common
"exceptional status in recording engineering and interpretation". I scanned the intros of some of the pieces using
the Zerobox 103 which had been hurriedly set up in the listening room. Ms. Manger took note of the rather
casual assembly with great calm and, as is normally the case, did not attempt to praise the sound qualities of her
own transducer. All that she mentioned was the development of new magnet systems for the Manger sound
transducer, known as MSW for short, as well as the improved adhesive and voice coils. And also the Manger
Holoprofile - a newly developed so-called sound lens made of a transparent special plastic material designed to
be stuck onto the metal ring of the bending wave transducer. Before Ms. Manger returned to the company base in
Mellrichstadt, she suggested I test the effect of this.
Let us have a brief look at the assembly of the Zerobox 103 before I describe my own listening impressions. The
system is made up of separate modules, i.e. the subwoofer fitted with two 10" Vifa bass drivers and the unit
standing on rubber feet to accommodate the three Manger sound transducers. The two bending wave transducers
at the side are faded out above 1000 Hertz with a gentle six-decibel filter and compensate the sound pressure
drop, which would occur at lower frequencies due to the limited cabinet size. In this way a quasi infinite baffle is
generated whereby the influence on the sound can be checked by removing a plug-in jumper. Incidentally the
Zerobox 103 can also be ordered with only one Manger sound transducer. Sooner or later the final version with
three MSW sound transducers is recommended however as this makes the radiation characteristic more open,
and at the same time the treble filter and the sound level reducer generated by series circuitry prevent irritations
or interference with the main bending wave transducer on the front side.
Protected by just one high pass filter of the first degree this transduces from only 150 Hertz the complete
frequency range right up to 35000 (!) Hertz. The acoustic qualities of the MSW sound transducer have been
further developed over a period of more than 20 years to achieve a precision that I had never before experienced.
After a rare-earth magnet had replaced the oxide magnet in 1988, a clear improvement in impulse velocity and
broad-band capacity was achieved by using an extremely strong neodymium drive combined with the reduction
of the coil gap to 0.95 mm and the improved adhesion bond to the twin voice coil.
It is well-known that the three-layer panel diaphragm does not have a piston-like movement, but oscillates in
itself, whereby different frequencies are radiated simultaneously from the diaphragm. Here the opposing massand-
spring forces within the diaphragm cancel each other out. The acoustic energy is led off with the sound in
the material to the star-shaped absorbers and converted into heat. Sound-distorting build-up and decay
phenomena are unknown in this bending wave transducer because it reproduces a frequency range of more than
eight octaves at a rise time of 0.012 milliseconds!
High tones are released from an almost punctiform area in the centre of the diaphragm and are therefore radiated
on a relatively large scale. The coincidence frequency of the "soft bending panel" with 80 kilohertz - in contrast
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with the "rigid bending transducers" such as NXT, Walsh or DDD drivers - is also well outside of the audible
range. At low frequencies on the other hand a transition to approximately piston-like movement takes place,
whereby + 3,5 millimetres stroke and a thermally high-load voice coil weighing only 0.4 grams ensure sound
pressure reserves in excess of 120 decibels. The occasional prejudices, which the Manger sound transducer is
still confronted with, completely disappear into thin air as we discovered later. However the complex assembly
of the driver prevents an automation of the manufacturing process, which explains the high price for the bending
wave transducer, which is available separately.
Traditionally Josef Manger combines his extremely phase-linear MSW in the bass range using bass units that are
installed airtight, and optimized for a low Q factor and therefore for a fast and overshoot-free response. Special
units by Vifa with rigid paper/carbon fibre diaphragm together with frequency cross-over with so-called zero
ohm transformer coils are used for this.
Returning to my initial impressions gathered in this magazine's own listening studio using the CD sampler
available directly from Manger. The first track isn't really music as such, but an example of sound - namely the
full peal of bells from the bell-tower of a church in Gütersloh. Anyone who can't hear the temporal precision and
dynamics of the clapper strikes within a matter of milliseconds is either deaf or has only ever heard the world as
an acoustically distorted recording. No loudspeaker sound, no individually audible loudspeaker clouds the
illusion that you are sitting right in the middle of the bell-tower. The unbelievable energy and crystalline purity
in the topmost treble range, combined with absolutely stress-free articulation, certainly had me immediately
convinced.
The second track is an extract from an SWF radio play from 1993. The difference between stereophonic effects
and the narrator's voice recorded in mono made it perfectly clear to me from the outset that I had not yet found
the perfect positioning for the Zerobox 103 in the room. So I got out my inch-tape and thread to symmetrically
align the position of listening location with the transducers. The result is astonishing and produces a razor-sharp
localization. Note: the bending wave transducers are intended to be aligned directly towards the listener, but it is
actually better to have an even more angular setting with the axes intersecting in front of the listening position.
Then you find that the central localization is perfect, and the sweet spot is increased, thus guaranteeing a
strikingly plastic image. And the strange thing about this is that the difference between "right" and "wrong" is
dramatic with these transducers and the listener intuitively finds the ideal listening position after only a couple of
tracks to enjoy the unbelievable precision.
The next track is a one-point recording by Denon with Bruno-Leonardo Gelber on a Steinway grand piano. After
exactly aligning the transducers I have the feeling that I am hearing not the loudspeaker but just the instrument
and the recording location in Notre Dame in Paris. I have never heard Beethoven's Sonata Opus 13 No. 8 like
this before. It is practically impossible to ascertain loudspeaker properties or characterizations in the form of
"dynamic bass", "transparency in the mid-tone range" or similar. The fact of the matter is that the grand piano,
the striking of the piano keys and the acoustic room surrounding the instrument are presented as a unified entity.
Here the striking of the piano keys and the sound-generating body of the grand piano are interlinked so that it
seems that the life-sized instrument is standing in front of me in the room. To the same degree that the Zerobox
103 almost disappears as "sound-determining factor" in a chain of reproduction, the perception of music,
interpretation and recording location move to the forefront. It should come as no surprise that studio engineers
and musicians have always valued the unique neutrality and precision of Manger sound transducers.
The next track is with vocals by Hermann Prey, Beethoven's "Ich liebe dich". And here we find the final proof.
Hardly any other loudspeaker can present a voice so uniformly and homogeneously in the room. It is utterly
impossible to localize the perfectly integrated bass parts.
A change of mood: the next track on the Manger CD, Vivaldi's "Winter", 3rd movement, lives from the
captivating dialogue between the solo violins and the tutti strings, from the thrilling tempo and energetic stress.
In this much-praised interpretation the historical instruments create an unmistakably intensive sound experience.
The following Haydn Symphony No. 67 begins considerably lighter and more carefree and takes me to the
acoustics of the Gewandhaus in Leipzig. This hitherto unreleased recording offers spatiality and vividness far
exceeding the limitations of the speaker arrangement. In quiet passages you can even hear individual members of
the audience clearing their throat or moving a chair and the true size of the room where the recording was made
is tangible. With my eyes closed the imaginary impression of the stage becomes clearer, and I can easily
compose this to a unified entity thanks to the magnificent impulse precision of the sounds and noises. As I am a
rare concert-goer, this was a fantastic experience for me.
The next tracks with discreet-virtuoso guitar-playing from the 19th century or the deep flageolet tones from the
Oriental Bass piece allow the soloists to be present in addition to continuously variable precision in sound
depiction and true representation of magnitude. Each breath and every effort of the musicians are an integral part
of a stage presence that can scarcely be surpassed in authenticity.
Even jazz music, something I seldom listen to, gains in fascination in the recording of the Treya Quartet made at
Divox Jazz. Surprising tempo changes, rising tension arches which then fall almost into the meditative in
conjunction with the sound fidelity of the individual instruments which can be precisely localized will be
enjoyed not only by jazz fans.
In contrast to this the track The Cost of Freedom with Marla Glen is clearly too powerful in the bass range. It is
unbelievable what sound pressure levels and depth are possible. However the comparison with the recording
Jazz Variants by The O-zone Percussion Group clearly illustrates that the percussion and the powerful Kondo
drums are captured absolutely perfectly, and even the three-dimensionality of the live recording cannot be
compared to the previously heard studio recording. The fact is that rarely has a transducer demonstrated to me
more clearly the qualities of the recording.
These experiences were confirmed in my home. This time however I listened to the Zerobox 103 with the
optional Holoprofile, costing extra. In my view this attachment improves primarily the radiation behaviour in the
harmonic spectrum, which had been previously typified by a drop in treble outside of the sweet spot. The effect
with the Holoprofile is absolutely comprehensible. Now the treble notes are more strongly scattered not only
laterally, but also vertically, and at the same time mid-frequencies seem even more vibrant and steady with
minimum attenuation of the upper peaks. The most striking factor however is the almost unbelievable gain in
spatiality and tonal uniformity, even outside of the ideal position.
Incidentally the Holoprofile does not negatively influence the pulse accuracy, and a decisive strength of the timetrue
Zerobox 103 freed from intrinsic sound remains, namely a precision in sound that can also be experienced in
critical rooms enabling the use of fast and high-resolution electronics without impairing the homogeneity and
stress-freedom of the sound pattern. This quality is achieved by only a handful of sound transducers in the world.