The diaphragm movement: how does the diaphragm move?
diaphragm does not move piston-like, as in cone loudspeakers,
the flat diaphragm vibrates on its own axis. The bending
waves move from the middle outwards, comparable to the
wave movement on a water surface after throwing in a stone.
Using Mother Nature as an example, the basilar diaphragm
of the human inner ear functions along the same wave principle
as the Manger sound transducer.
shape: why this star shape?
star shaped absorber, nowadays a hallmark of the Manger
sound transducer, is not a designer’s idea but has
a necessary function. The outward moving waves must be
dampened at the edge of the diaphragm. The star absorber
acts like a reed belt along a riverbank, which prevents
the waves being bounced back to add to the oncoming waves.
frequency: where is the crossover frequency between the
Manger sound transducer and bass drivers?
crossover frequency from the Manger sound transducer to
the bass drivers lies between 140 - 170 Hz, depending
on the choice of the bass drivers.
connecting wires: why does the Manger sound transducer
have 4 connecting wires?
Manger sound transducer works with 2 voice coils, which
are electrically connected in parallel. These 2 coils
lie adjacent to one another on a supporting frame. When
one moves out of the air gap, an undesirable opposing
force appears as a result of counter induction. This impairs
the actual coil movement. However, as the second voice
coil simultaneously moves into the magnetic field, the
energy forces are neutralised and the opposing force is
cancelled out. The voice coil is only moved time correctly
by the music signal. Using the patented twin voice coil
principle, the Manger sound transducer achieves an extremely
fast rise time of 12µs. for lower frequencies i.e.
with slower movements, these 2 adjacent coils act as one
long voice coil and achieve a maximum excursion of +/-
time: does the Manger sound transducer have a burn-in
just like every other loudspeaker chassis, the Manger
sound transducer has a
recommended burn-in time of 24 hours.
are the Manger sound transducers selected in matched pairs?
due to the very strict mechanical tolerances of the Manger
sound transducer the maximum permitted deviation in frequency
range is 0.5dB. Stringent quality checks give each Manger
sound transducer its own measurement protocol.
can the Manger sound transducer be repaired?
basically speaking the Manger sound transducer is repairable.
Coil and diaphragm can be replaced, the basket and magnet
are there still any improvements possible to the Manger
Manger sound transducer has reached a technical level
that does not envisage any improvements in the foreseeable
future. In the long term the Manger sound transducer can
always be modified. In this respect all our clients are
kept up to date on any developments.
term stability: how is the long-term stability of the
Manger sound transducer?
the burn-in phase of 24 hours, the Manger sound transducer
does not alter. Our own positive, long term tests have
been obtained from recording studios which have been using
the Manger sound transducers since the mid 80s. There
they are driven daily at high volume levels for 12-14
hours. After measuring, no deviations from the original
test protocol could be detected.
how are the Thiele-Small parameters?
Thiele-Small parameters are invalid for the Manger sound
transducer. These are based on an equivalent circuit diagram
of a piston loudspeaker with mass/spring characteristics.
The Manger sound transducer works however, according to
the bending wave principle and acts almost like a resistor.
Manger sound transducer is at a technical level where
no more teething problems occur. Any Manger sound transducer
from 1986 onwards can be modified, should future improvements
through new materials be reached. This means you can always
achieve the latest technical standard via modifications
without investing in new equipment.
temperature: what is the optimal room temperature for
the Manger sound transducer?
Manger sound transducer functions optimally within a room
temperature range of
15-35°C. other temperatures e.g. as in cars, alter
the material properties and thereby impair the audio reproduction.
which amplifiers are best for the Manger sound transducer?
on our experience, the most suitable amplifiers are those
with a high bandwidth, in excess of 150kHz. The higher
the upper value of the frequency range, the more precise
the acoustic details will be reproduced by the Manger
are there any differences between the Zerobox models?
major difference between our Zerobox models lies in the
low frequency range having differing lowest frequency
limits depending on the bass driver chassis used and cabinet
Zerobox model is correct choice?
correct choice depends on different factors: room size,
placement in the room and listening habits. Direct contact
with us on an individual basis is highly recommended.
are three Manger transducers the preferred choice in ZB
only one transducer in the loudspeaker housing, a typical
to one half of the original value occurs as soon as the
matches the housing width. With the two extra bending
wave transducers mounted in either side of the cabinet
the side-mounted drivers create an acoustic baffle, with
no omnidirectional radiation. The front driver is still
the main driver, and the side drivers are switched in
serial with a coil, so that they just support the front
driver's radiation like an infinite baffle. The side-mounted
drivers are faded out above 1000 Hz with a gentle six-decibel
filter. The result is that you can't recognise the cabinet
the MSW be used as a dipole tweeter? I.e. on an open baffle.
can be used, but we don't recommend it. The Manger driver
works more controlled in the low frequencies if the drivers
is built in a sealed cabinet. The spring behaviour of
the air controls the diaphragm movement at the low end.
You can also drive the Manger with more power.
If I crossover @ 1500hZ from my Volt BM2500.4
bass mid driver, do I still connect both sets of voice
of the crossover frequency both voice coils are always
switched in parallel. The two parallel-switched voice
coils creates the fast rise time on one hand and on the
other hand an excursion of +/- 3.5 mm.
We wouldn't recommend a crossover frequency which is that
high, because localisation and image should be created
only by the Manger not from both drivers. The highest
fg should be around 600 - 800 Hz.
In the Zerobox speakers we use a crossover frequency of
150 - 180 Hz!
there any preferred arrangement with regard to the orientation
of the transducer in the speaker cabinet? For example,
is there a preferred position for each of the leads across
the diaphragm in terms of, say, a clock face
is no preferred arrangement, the driver’s work concentric
and coplanar. We just use the symmetrical axis for aesthetic
which kind of music is the Manger sound transducer best
Manger sound transducer is suitable for all music styles;
it reveals the natural content of every sound medium.
Unfortunately this can sometimes show up poor quality
recordings. We gladly send you our reference CD as a comparison