Precision Sound Reproducers
new technology based on study of human hearing. After a decade of
deve- lopment, they now address all known detection mecha- nisms in
the human ear and take
into account the way our brain deals with periodic and aperiodic sounds
in rever- berant
environments. This re- sults in the ability to repro- duce both
and aperiodic sounds in a stunningly
realistic and natural way, and to greatly reduce listening fatigue.
Precision Sound Reproducers are not just excellent or of better
quality. While they are they more importantly present new and uncommon
that you can hear immediately. Like
a black and white television set does not address the color-sensitive
in your eyes, and doesn't take into account the ability of your brain
to extract information from the differences between the separate images
eye, traditional loudspeakers generally do not address two of
three detection systems in your ears, and don't take into account the
way the brain deals with sound in reverberant environments. When you
reproducers the experience can be compared to seeing a 3D
color TV when
were used to flat black and white units only, and thought that
these were the best that ever
could be achieved. The discovery can be surprising, it can
sometimes even be slightly disturbing for a short
while. But once you become
used to it, which usually happens all by itself and in a short time,
eventually be dissapointing, as the results are rich, pleasing and
allowing for more relaxed listening. Legends allow for actual
near-concert expereinces. The fidelity and smoothness on all sounds is
The human ear has three known detection mechanisms, two of which work in the time domain. Traditional loudspeaker systems do not address these and only talk to the detector that recognises pitch and volume. We then can recognise the reproduced sound but we also note the sound is not ‘real’, is not happening in the room and misses information. Our brain will then try to fill the gaps from memory which in turn creates ‘listening fatigue’. The LEGEND systems correctly address all three detection mechanisms allowing for sounds to appear ‘real’, detailed and complete, and for the listening experience to feel natural and relaxed.
room compensation system in existence is the one build into our heads:
our brain. But for this natural system to work well, sound must be
radiated in a way the brain is used to. Most natural
sound events, like
when an object hits the floor, are pulse shaped,
omnidirectional and have their origin in a small area. LEGEND systems
are pulse correct virtual point sources. All
sounds emitted originate from the same small spot, that
radiates the same way in all directions. Now the brain can deal with
the reflections in the same way it does in daily life and relax,
while with traditional speakers it must transform, correct and
radiation pattern of a LEGEND Sound Reproducer is not intended to
imitate that of a musical instrument. It's intention is to transmit
information to the
human ear and brain in such a way that our hearing system can
deal with the reverberations
in the listening room in the most natural way, so that it can recover
and appreciate the recorded
signal. This will then subsequently allow our brain to reconstruct the
sonic space of the recorded environment. LEGEND systems do not require
a room compensator or special acoustic treatment of the listening
the brain will now deal with the reflections naturally.
Precision Sound Reproducers not only reproduce tones and notes
(periodic sounds) beautifully, they also reproduce noises and events
(aperiodic sounds) with high fidelity, so these also sound
realistic. This is something that is lacking in many traditional
speakers. With event sounds and noises we mean sounds like clicks and
clacks, a closing door, putting a cup back on
the table or an object falling on the floor. With traditional speakers
we can recognise these sounds but we also clearly hear that they are
not happening in the room. With Legends this is different: events do
sound real. Our ears have specific
detection mechanisms for hearing aperiodic sound events and for hearing
timbres (periodic sounds), and the brain has
specific ways to deal with these sounds in reverberant environments.
loudspeakers do not take this into account and often only concentrate
on the reproduction of tones. Music, however, is also
full of non-periodic (noise) events. This is very much true for
percussion but also the onsets of many tones are perceived by the
detector' systems in our ears. Not addressing these could be compared
showing black and white pictures in stead of color. Creating a single
unit capable of correctly addressing all known human detection systems
been quite a challenge, but now that it exists, the results are
quite spectacular and the difference is heard from the first seconds
onwards. And the capability to reproduce tones, timbres and dynamics
been taken care of as well, uncompromised, at the best quality levels
Ultimate transparency and realism
Can reproduce sonic space
and detailed sound stage
reproduction of onsets and sound events
Easily adapts to your listening environment
High information capacity
Relaxed listening for long hours, no fatigue
‘hot-spot’ for the sound image
Sound in all areas of your room
Transient distortion free
Phase linear over the entire range
360 degree fully omnidirectional
A single and small virtual point source
Includes a secondary, acoustical cross-over
Complete frequency spectrum
High power and dynamics
phase linear subwoofer
high quality power amplfication
LEGEND Precision Sound Reproducers are sometimes called ”The Loudspeakers you don't hear” because they add so little to the signal that you only hear the recorded signal, and not the loudspeaker. They have no 'footprint'. Additionally, the small point sources create a floating sound image so convincing that it seems as if no sound is actually coming from the speaker units itself. A 3D cloud of sound is appearing between the units and the units themselves seem silent. Both these characteristics resulted in the use of the phrase ”The Loudspeakers you don't hear”.
LEGEND 4000 Precision Sound Reproducer by John Watkinson
|Description||Floor-standing phase linear virtual point source active speaker system|
|Frequency response||20 Hz – 35 kHz|
|Max SPL @ 1m||115 dBA|
|Noise SPL @ 1cm||Under
hearing treshold at 1 cm
to 15 micro seconds (0,000015 s)
amplification is built-in. The units connect to a pre-amplifier output.
electronic active phase linear proprietary cross-over circuits
total, Instantanous peak power 800W
|Power aplification type||Class
A-B, a separate amplifier for each frequency channel, convection cooled
|Power supply type||Toroidal
transformer, high grade capacitors and regulators. Dual Symmetrical.
|Drive units||2 x
20 cm long throw woofers with 7.5 cm coils and neodymium magnets
1 x 10 cm midrange with 5 cm voice coil and neodymium magnet system
1 x 20 cm bending wave driver with 7 cm coil and neodymium magnets
|Acoustical processing||Proprietary sound reflector and wave guide system, which re-assembles frequency channels and creates an omnidirectional virtual point source|
|Enclosure||Separately sealed enclosures for each frequency channel, braced plate steel|
Analogue +4 dbU
230V AC switchable, 50Hz or 60 Hz, fuse 3A (120V) or 1.6 A (230V)
|Input connectors||1 x
analogue balanced XLR, 1 x IEC power input connector
|Dimensions||75 x 26.5 x 26.5 cm (29.5 x 10.4 x 10.4 inch)|
kg (55 lbs)
painted wood and anodised aluminium
Custom colours and wood finishes are possible
Q: If a system is tested to reproduce all frequencies then all sounds will be reproduced correctly, no?
No. Testing a sound reproduction system with only sine waves is like
testing a car on a straight track without ever using the wheel or the
brakes. Most natural sounds and also music include lots of impulse
waveforms, and are not sinusoidal per se. To reproduce impulse shaped
random sound events correctly, all frequency channels must work in
phase and with equal delays, and so in all directions. They also need
to originate all from the same
spot or else the reflected sounds will still have their shapes damaged.
Also transient distortion needs to be absent for impulse shaped sounds
to be reproduced undamaged. Sine wave tests do not measure any of this.
Q: It has been demonstrated that the ear is phase deaf. Why do you bother about phase-linearity?
A: These demonstrations used continuous (steady state) sounds. On steady state tones only one of three detection mechanisms in the ear is active, and indeed, that one, the basilar membrane, does not detect phase. Two other detections are active on the onset of a sounds only. Phase errors are detected quite well at that time, because phase inaccuracies damage pulse shaped waveforms. The result of damaged onsets is lack of realism, a poor sound stage, a narrow sweet spot, sounds not staying sparate, and listening fatigue.
Q: Can you tell a bit more about these sound detection mechanisms in human hearing?
have three sound detection mechanisms. When a new sound is perceived
they work sequentially. The first detection is for direction. Only time
is measured and only the
very first pressure change is used. Volume or pitch are not considered
here. Time difference between the two ears provides
information about where the sound is coming from. The second analysis
is measuring the time between the beginning of the sound event and when
the air pressure passes the zero point again. This again is a time
measurement only. It provides information about the size of the object
that produced the
this we will evaluate pitch, timbre and volume, using the basilar
membrane, the third detection mechanism.
Q: Is this new? How come I never knew about this?
Altough the human ear did not change recently the knowledge about it
did. But it also is not very new as this knowledge is now almost 30
years old, and suspecting such mechanisms is even older: We
know for much longer that we can estimate direction precisely and with
the basilar membrane mechanism only this could not be fully explained,
so these discoveries were not a big surprise.
However, the legacy loudspeaker concept does not take this
knowledge into account. The
basic principles of many new loudspeakers are still
similar to those of 70 years ago. Tradition can be hard to beat but one
can wonder why a 70 year old loudspeaker concept is still considered
current today, while the concepts of radios, TV's, telephones,
and cars from that period are now charished for by
collectors and museums.
Q: You have presented LEGENDS at High End audio shows. How do they compare to established High End HiFi systems in general?
beats most of them, if not all. After listening to Legends for a while
it can be difficult to go back. Imagine a show where people are
comparing subtle differences in the qualities of grey scale rendering.
And then there is this one room with a color TV ....
Q: I was told that reflected sound should be eliminated. Why are your speakers radiating all around instead?
A: Most traditional loudspeakers radiate unbalanced sound from the sides and from the back. The reflections of these you will want to eliminate indeed. But time-correct, and well balanced reflected sound is actually an advantage to the listening experience. Human hearing is perfectly at ease with reflected sound during daily life and also with live music. Traditional loudspeakers, however, create challenges to the way human hearing deals with reflected sound, as the compromised sound from the sides or from the back creates difficulties for the brain in linking the reflections with the proper direct sound events. Reflections resulting from a coherent source to begin with, as those coming from an original sound event, from a musical instrument or from a LEGEND omnidirectional point source, will be easy to link for the brain, and will therefore not disturb and instead enhance the listening experience. It will allow our brain to work naturally as a room compensator and reconstruct the original source signal. Heavy room treatement will then not be needed.
Q: What is ‘transient distortion’ and why is it so important to avoid it?
is distortion caused by the inertia (mass) of driver membranes and
When a loudspeaker reproduces a sine wave, the mass of the moving parts
is not a problem as they oscillate like a string does. Now imagine you
pull the signal plug suddenly. The oscillating membrane will not be
immediately and will continue to produce some sound for a short while
caused by stored energy, before it comes to rest. Energy can be stored
both in the speed of
and/or in springloads. As a result, sound is produced
that was not
present in the signal. In musical signals sudden changes happen all the
We call them transients. Traditional loudspeakers often produce
significant amounts of this spurious sound, masking real information
and causing listening fatigue. This is often felt as ‘aggressive’. And
as it damages pulse shaped waveforms as well, it also impairs realism
sound stage. It is a prominent problem in traditional
loudspeakers, and the absence of it is already well known as a specific
electrostatic loudspeakers. Vynil disks can contain less transients and
therefore often are considered less agressive than digital. The
aggressiveness, however, often is not due to the CD itself but rather
to the inability of the loudspeaker to deal with the transient
information present on the CD. Legends can reproduce the transient
information faithfully and without the distortion, allowing for digital
sources to sound rich, detailed and without aggression.
Q: Phase linear, pulse correct, transient distortion free, omnidirectional, virtual point source, full frequency range, high power and dynamics, build-in phase linear subwoofer,…. It all has been done before. What is so special about your system?
The special thing is to have this all united at the same time in a
single unit. This is
needed because our human hearing is very good at detecting any error
in sound reproduction and easily classifies sound as ‘not real’ if
missing or wrong.
For the magic to happen, ALL these features must be present
What use is a speedy car if the breaks are no good? But a car with good
breaks and a lousy engine isn’t much fun either. It needs to work all
in the same device. We are not aware of any other products that achieve
such a total approach.
Q: What has been done technically to achieve this?
The LEGENDs have many technical features. These include
new mechanical, new acoustical, and new electronic solutions. Often a
of these is doing the job. It is a long list,
which can not fit here completely. Here are a few examples:
Q: Scientifically / technically very interesting. But what are the listening advantages for me as a music lover?
The LEGEND Precision Sound Reproducers not only reproduce tones and
notes, they also correctly reproduce sounds and noises. As a result,
finally sounds real and so do the onsets of notes. This is unique to
our knowledge. There are also a number of other listening advantages
not common to loudspeakers
in general: * The listening experience is close to the concert
experience, sounds are very ‘real’. * Transparency: Minimal footprint -
You do not hear the
loudspeakers, you just hear the music. * More information from
the recording (from the musicians) is
conveyed to you as a listener. * Sonic space may be reproduced: You
not only hear the music, you can also hear the room the music was
recorded in. * Your natural selection filter will work again and will
allow you to
highlight musicians among others in the sound image at your free
choice using your brain. * Thanks to this you can choose to have a
experience while listening to the same recording. * A rich,
precise and detailed soundstage image. * A wide sweet spot: more
can enjoy the music sound stage simultaneously, more freedom of
movement. * A high
‘Spouse Acceptance Factor’ (SAF) as the units are of reasonable size
shape and placement is less critical. * Excellent sound in all places
of the room. * Generally no acoustic
room treatments are needed. * Reduced listning fatigue - you can listen
for many hours without getting tired.
What does it sound like? Can you try to compare it to anything I might
The most unusual aspect is that it sounds much more like how real
sounds sound. This is quite unusual for loudspeakers so you may be
surprised and you may need a short while to get used to that, after
which you can enjoy music as if you were at the concert hall, or like
if you were in a Jazz club. Closing
your eyes makes the illusion more complete as the brain privileges
visual information above sound. Some have compared the clarity of the
sound to that of electrostatic or panel loudspeakers (as these can also
reproduce pulses and phase) but then without the
usual drawbacks in size, lack of dynamics, critical placement and lack
of, or problems with bass.
The reproduction of sonic
space is unique however, as this requires both the ability to reproduce
pulse shapes and phase as well as the omnidirectional point source. We
are not aware of any other loudspeaker concept capable of combining all
features. The gain in realism is not sublte. It can be heard and noted
immediately, within a second. Some have compared it to seeing in color
after having know B/W only, or hearing stereo or seeing in 3D for the
Q: Will this work with the music collection I own? Or does it require special recordings to work?
A: The system will work well with any recording. Given the precision of the LEGEND Sound Reproducers you may be able to better differentiate between recording qualities then you could before. To enjoy the best performance of the system, recordings that were less manipulated or less 'tweaked', seem to work best, as these often have better preserved information in the time domain. This includes both recent and old recordings. We have collected quite some and we are happy to demonstrate and share our lists of titles with you. But any recording will sound well or better on a LEGEND system, as LEGENDs reproduce any input signal very accurately.
Q: Will it work with my existing player / amp / room?
Yes. Most HiFi players and
electronics we tested performed quite well, also for phase and
impulse. Investing in a good DAC can be useful, becaue we found
that some of the (cheaper) DAC's can damage pulse shaped wave forms.
amplification is included so you would connect the LEGEND's to the
output of a pre-amp or to the pre-outs of your integrated amp. Your
HiFi shop can advice you on how to best connect them. Concerning
the room: Eventhough LEGEND Precision Sound Reproducers will work
well even when set against a wall, we advice to keep ideally one meter
free space around it if possible for maximum enjoyment. If the room
acoustics are good enough to have a
relaxed conversation than it will be good enough to listen to LEGEND's
as well. Special acoustic room treatment is generally not needed.
I own an excellent DAC. Will it's performance be
annihilated by your system digitising the signal again? And also: does
it work with vinyl discs?
You will be able to enjoy the
full performance of your DAC. Our system is entirely analogue and does
not digitise the signal in any way. LEGENDs also work well with vinyl
discs - you can
enjoy an entirely analogue signal chain with the LEGENDs, without
digitasion anywhere in the chain.
Q: Why do you use neodymium
Neodymium magnets have stronger fields, empowering the
driver motors to better control the membranes and limit distortion.
Furthermore, ferrite magnets also have a few other
drawbacks for precise sound reproduction: ferrite is an electrical
insulator which is not optimal for damping and lastly ferrite allows
the magnetic field to
move inside the magnet, failing to provide for a sturdy, solid base for
the motor to push and pull from.
Why did you make an active
system? Is there
something wrong with a good external amplifier and passive cross-over
A: Some of the specific processing we
do to pair the
electronic cross-over with the secondary acoustic cross-over can not be
done with only passive components. Furthermore, yes, passive cross-over
filters in general
do indeed present a number of drawbacks for precise sound reproduction:
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Texts on this page were written by and copyright Kommer Kleijn.