Four
absolute fi d e l i ty®
Owners Manual and Set-up Guide
The Genesis 4 Loudspeaker
Contents
SET-UP GUIDE 1
PLANNING THE PLACEMENT 1
UNPACKING AND POSITIONING 1
LOUDSPEAKER CONNECTIONS 2
LOUDSPEAKER CONTROLS 3
SERVO-CONTROLLED BASS AMPLIFIER PROTECTION 4
A WORD ABOUT FINISH 4
INITIAL SET-UP 5
SOUND CONTROLS 5
BEGIN WITH BASS TUNING 5
IMAGING AND SOUNDSTAGE 6
THE REFINEMENT STAGE 8
MAKE ONE CHANGE AT A TIME 8
DEFINING THE SOUNDSTAGE 9
APPROPRIATE MID-BASS/LOW-BASS BALANCE 9
ROOM TREATMENT 10
MASTERING THE REFINEMENTS OF THE SYSTEM 11
THE TECHNOLOGY 13
DESIGN PHILOSOPHY 13
THE GENESIS RING-RADIATOR RIBBON TWEETER 14
6-INCH RIBBON MIDRANGE 14
TITANIUM MID-BASS COUPLER 15
PROPRIETARY CROSSOVER TOPOLOGY 15
THE SERVO-BASS ADVANTAGE 15
THE SERVO-CONTROLLED WOOFERS 16
SERVO-CONTROLLED BASS AMPLIFIER 17
THE ACOUSTIC SUSPENSION 17
SPECIFICATIONS 19
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A Message from Genesis
Thank you for your purchase of one of the finest loudspeakers in
the world and congratulations for making the great decision to pick
the Genesis 4. The G4s were developed from the ground-up, but
based on technologies that have evolved over the past 40 years in
constant production.
The G4 loudspeaker is designed to reproduce music (and film) at
live listening levels with virtually no restrictions on dynamic range,
frequency response, or imaging capabilities in a medium-sized
living room. This is absolute fidelity® the ability to reproduce the
musical event faithfully, as was intended by the performer or
filmmaker.
However, the G4 is not meant to reproduce music at ear-splitting
levels. If you are looking for just LOUD, this is the wrong
loudspeaker. It will produce music with nuance, emotion and detail;
movie dialog will be the clearest you have ever heard. We
emphasize quality over quantity.... always.
This is the loudspeaker for a family to enjoy. While other
loudspeakers are designed to reproduce music perfectly for one
solitary listener at one precisely located sweet-spot, the G4 is
designed to deliver music to a much larger audience. In a typical
listening room, the listening sweet-spot extends in width to a
loveseat and even a 4-seater couch.
Please read this Owners Manual and Set-up Guide thoroughly to
get the maximum enjoyment out of your purchase. Also, please
check back at our website at www.genesisloudspeakers.com. We
will put the latest updates, tips and tricks, and support for our
owners on our website and in our newsletter.
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Please write the purchase details of your Genesis 4 loudspeaker
here for future reference. Remember; send in your registration
card to extend the limited warranty on your loudspeakers.
Bought from: ____________________________
____________________________
Date: ___________________________________
Serial Numbers:
Warranty Statement and Extended Registration Card
should be placed here.
Please check with Genesis should they be missing.
Remember – the warranty on your Genesis loudspeakers is
only for 90 days unless the Extended Registration Card
is sent directly to Genesis.
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Set-up Guide
Now that you have your new Genesis 4 loudspeakers, we realize
that you can’t wait to hook it up and start the music! However, we
want you to set it up correctly to derive the greatest enjoyment from
your purchase.
So, please read this set up guide (even if your dealer is setting it up
for you!) before you proceed.
Planning the Placement
Although the G4 is designed for ease of placement foremost, there
should still be some considerations to be made. You will not need
a very large room, but at a minimum the room should be at least 12
feet (4m) wide where the speakers will be placed.
You should have at least 4 inches (10cm) of space behind the
speakers and at least 8 inches (20cm) on either side of the
speaker. The listening position should be a minimum of 9 feet
(about 3m) from the front of the speaker to allow for proper
integration of the drivers.
In a typical placement, the two speakers will be about seven feet to
nine feet (2m to 2.7m) apart measured from center to center. The
speakers fire straight ahead with no toe-in.
As the room will greatly influence the sound of your system, finetuning adjustments will be necessary. Every room will be different,
with doorways, furniture, closets, wall construction and covering,
etc. all making a significant impact on the sound. Luckily, the G4
provides sufficient adjustability to conform to almost any acoustic
environment!
Unpacking and Positioning
The Genesis 4 loudspeakerwill arrive in a two large wooden
shipping crates. As the speaker weighs over 100 lbs each (more
with the shipping crates), we suggest that you get some help. We
are not liable for damage (to either the speakers or your backs!)
during unpacking and setting up.
The speaker ships standing up and slides out of the crate. So, we
suggest that you position the crates approximately at the final
position where you want the loudspeaker to be. The front and top
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of the crate form a lid that is removed and then the speaker can be
easily pulled out.
After unpacking, we strongly suggest that the crates be dismantled,
flattened and safely stored away in a cool, dry place. It is expensive
to custom build crates strong enough to transport these
loudspeakers without damage should you need to relocate.
The G4s incorporate an “acoustic suspension” that is designed to
ensure that they will work regardless of the type of surface they are
placed on. The speakers are de-coupled from the HMWA
suspension frame, and the suspension frame is coupled to the floor
using adjustable spikes. The system works best when the spikes
barely emerge from the bottom of the suspension frame.
If the speaker is placed on a hardwood floor, a copper penny may
be used under the spike to protect the finish of the floor. Do not use
large, solid “spike cups” as these will not allow the spike to properly
couple the suspension frame to the floor.
If a very thick carpet covers the floor, then the longer spike should
be used.
Loudspeaker Connections
Once you have the G4s close to where you think they will ultimately
be, connect the loudspeaker to your power amplifier using a pair of
high quality loudspeaker cables (not supplied) to the 5-way binding
posts. We have designed a “Loudspeaker Interface Cable”
specifically for Genesis loudspeakers for this critical job. More
information can be found from the Genesis website or from your
dealer. However, any well-designed loudspeaker cable can be
used.
A power cord is also needed to power the built-in servo-bass
amplifier. A “starter cord” is provided with the loudspeaker, however
the bass will improve with a higher-quality power cord. As the G4s
contains a 500W Class D amplifier module per side, make sure
that any power cord you use is up to this job. An “Amplifier Power
Interface Cable” is also available from Genesis for this.
Before you plug in the power cord, make sure that the voltage
switch is correctly set for your country.
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Loudspeaker Controls
You will notice four control knobs on the back of the G4. These are
labelled “BASS GAIN”, “LOW PASS”, “SOFT/BRIGHT” and “TIGHT/WARM”.
Set them initially pointing straight up – the 12 o’clock position. This
is the nominal flat position and will work for the majority of
installations.
For a minimum-sized room, the bass gain should be set at 3 and
the low pass should be 115Hz. In general, these two controls are
mirror-imaged. When you turn the bass gain to the left, the low
pass should be turned an equivalent amount to the right.
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Servo-Controlled Bass Amplifier Protection
The servo-bass amplifier has numerous protection circuits built in to
protect both the amplifier and the woofers. The amplifier is
designed to be current-limited to 20amps – this is more than
enough to supply over 1,200W transients to the pair of 10” woofers.
However, the servo-system in the G4 is not compression or
dynamic limited. Hence, it is possible to play the system too loud,
and damage the woofers (and also possibly your ears).
If you over-drive the amplifier, it will self-protect and you will hear
clicking or snapping sounds. This is caused by the amplifier limiting
current to the woofers (much like the over-rev fuel-cut off in car
engines). If that happens, turn down the volume of your system to
protect your hearing and your speakers.
The amplifier, although it is very efficient, also has a thermal cut-off
to protect against over-heating. Should the bass amplifiers turn off
and the back plate is very hot to the touch, turn the system off until
it cools down again. Additional ventilation might be needed at the
back of the speakers should this happen too often.
A Word about Finish
The G4 is finished to a high degree of gloss. Use only a damp cloth
to wipe the speakers down. In particular, DO NOT use paper
towels to wipe the surface of your loudspeakers. Paper fibres are
extremely abrasive and can introduce fine scratches on the surface
that will “cloud” the finish.
Treat the cabinet as you would a fine piece of furniture. If polish is
used, please avoid getting any on the drivers.
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Initial Set-up
Music is the best way to begin to setup your speakers. While we
deliver the G4 after at least 24 hours of running-in, further finetuning of your system may be necessary after 400 hours or so. As
the loudspeaker system breaks in, it will sound better and better.
A comprehensive Genesis Loudspeaker Set-up Procedure with
music suggestions is included at the back of this owner’s manual,
or the latest version can be downloaded from the Genesis website
at www.genesisloudspeakers.com. This section gets you going so
that you can begin to enjoy your new speakers. Taking the time to
properly set-up the speakers will guarantee you long term
enjoyment.
Sound Controls
The knob marked SOFT/BRIGHT controls the output of the front
tweeter. Start with this control at the 12 o'clock position. Turning the
control to the left (counter-clockwise) will result in a softer sound,
and turning to the right (clockwise) will result in a brighter sound.
The TIGHT/WARM control is a five-position switch used to adjust the
‘warmth’ frequencies around 150Hz. Start with the control at
position three (the 12 o’clock position). Position one and two will
sound leaner while position four and five will sound warmer.
There is no “correct” setting as it will depend on the room and also
listener preference.
Begin with Bass Tuning
At Genesis, we believe that bass is the foundation of music, and it
is important to get the bass right before we even start to “dial” in the
rest of the frequency range. Unfortunately, bass is also the most
difficult to get right because it is affected by how close the speaker
is to the nearest wall, the size of the room, where in the room they
are positioned and even the furnishings. A very large, soft leathercovered sofa can absorb up to 6dB in the bass frequencies. If you
can feel the sofa vibrating under your bottom, you can be sure that
it is also absorbing those frequencies.
Also, the height mode of the room is usually the most problematic
frequency. This is because the height of the room from ceiling to
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floor (anywhere from 8 feet to 12 feet) corresponds to the
wavelength of sound from about 92Hz to about 140Hz.
A very easy way to very quickly set-up the bass is to use a sound
pressure meter. Even a smart phone with a sound pressure app
will work as we need to set relative level. We recommend using
test tones at about 300Hz and 60hz to rough the system in.
Play the 300Hz tone, and measure the sound pressure level at the
listening position. Then, play the 60Hz tone and adjust the BASS
GAIN until the sound pressure level matches the 300Hz tone. Next,
adjust the LOW PASS setting to mirror-image the BASS GAIN.
If, at this point, it does not have enough mid bass (male singers
sound too skinny), turn the low pass up slightly or alternately
position the speakers closer together in order to achieve better
lower midrange coupling between the main speakers. If he sounds
too fat turn the low pass control down slightly or adjust the gain
down.
When you have had a bit more time to know your speakers better,
you will be able tailor the sound of the G4s to your preferences. In
the meantime, you should already have a flat in-room frequency
response after this step.
Imaging and Soundstage
While imaging and soundstage are controversial subjects (how do
you ever know that the soundstage is recorded correctly in the first
place??), it is vitally important to our enjoyment of a recorded
musical event. The G4 is able to deliver a realistic soundstage only
if the recording contains such realism.
If your vocal selection is a well-recorded audiophile CD or LP, the
performer (assuming that he or she is not very close miked) should
appear to come from between and behind the loudspeakers and be
at the appropriate height and size for a standing person. If it is not,
there are several remedies that will address this.
If the voice is shifted to one side (left or right), move the speaker
which the voice is apparently closer to slightly (about ¼” or 6mm)
backwards until the voice centers. You can also move the speaker
which is apparently further from the voice forwards the same
amount.
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Assuming that the vocal recording is accurate, if the vocalist
appears to be larger than life, you should first check the system
volume. Is it a volume that would be appropriate for someone
actually singing in your room? If there is too much volume the
artist will appear too big and the opposite is true for too little
volume. If the volume is set correctly and the image is still too big,
toe the speakers in a very slight amount or place them closer
together and re-listen. Repeat this process till you have it right.
The total toe-in should be no more than about 5 deg.
If the voice is too low in height, tilt the BACK of the speaker up
using the adjustable spikes. There are many solo vocal recordings
where the singer is recorded using a microphone hung above head
height. In this case, it is correct for the system to portray a singer
that seems to be singing from a pit in between your loudspeakers.
If you have the speakers too close the front wall, and you are not
getting enough front to back depth (the singer not appearing behind
the speaker enough) pull the midrange tweeter panels away from
the front wall a little bit at a time. If you do not have them pulled far
enough away, you may not have enough front to back depth. If
you get the speakers much beyond 1/3 of the way into the room,
it is unlikely that pulling them further away is reasonable.
Too much absorption on the wall behind the speakers will also
result in less depth in the soundstage. The G4 requires a
relatively “live” front wall.
Find the best compromise for your room, your tastes and your
space requirements. If the speakers are too far apart you will lose
the side image and the image density in the middle of the
soundstage will be too diffuse. If the speakers are too close
together you will have too small a center stage, and you may find
that the edges of the soundstage collapse inwards.
We recommend you begin somewhere between six to seven feet
apart as measured from center to center. And then move the
speakers apart small increments at a time as you tune the system.
They seldom work well closer than six feet apart or much more
than nine feet apart.
If you are not getting proper focus of the soundstage, you may
angle the speakers inwards 1 to 3 degrees (but no more) towards
your seating position until you have a properly defined soundstage
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image. The usual reason that you will want to do this is that you
have a “W” soundstage. The sound images are most dense (or
focussed) in the middle, and then dense around where the
speakers are, but less dense between the center and the speaker.
When properly set up very little sound should appear to come
directly from the speaker, instead, the sound stage should extend
far beyond the left and right edge of the loudspeakers and they
should have tremendous front to back depth. When the recording is
close miked (when the instrument or performer is very close to the
recording microphone) the music may appear to come directly
from the loudspeaker or projected forward of the loudspeakers.
This is normal. Typically, however, the sound should appear to be
detached from the loudspeakers.
A simple rule of thumb to follow is that focus will be achieved by
placing the speakers closer together or farther apart, and front to
back depth can be adjusted by the distance from the front wall and
treatment (or lack of) of the front wall. Further, as the system
“breaks in”, the depth and width of the soundstage will increase,
and so will the “smoothness” of the sound.
Ultimately, it is all about balance. You have a number of controls
at hand with which to adjust the bass response, the low-pass filter
frequency and woofer volume. You can also move the speakers
closer together (for better coupling) or further apart.
The Refinement stage
After following the rough setup guide above, live with the results for
a while before attempting to refine further – give the speakers a
chance to run in. Then, follow the Genesis Loudspeaker Set-Up
process to dial the speakers in.
Make One Change At A Time
One rule of thumb you should always keep in mind. Make one
change at a time! Do not, for instance, change position of the
speakers and make an adjustment to the bass amplifier all at once.
Make each of these changes separately and note the difference by listening - with each adjustment, then make the next change.
Each adjustment, in positioning, and in control adjustment will
result in a subtle sonic change. Even when you are moving the
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midrange/tweeter panels further apart, or closer together, move
one panel, listen, and then move the other panel. You may also
find an asymmetric placement in-room more accurate and pleasing
as the furniture and the room may be asymmetric in the first place.
Defining the Soundstage
A common problem we find with many set-ups is a tendency to
separate the speakers too far from each other. This gives an
unnaturally stretched soundstage between the two speakers, and
creates problems with focus. The key problem is a lack of
soundstage information beyond the left and right sides of the
speakers.
If you find that the sound is not spacious enough or you are not
getting enough front to back depth, pull the speaker away from the
front wall. This is typically preferable to separating the two
speakers too far, and will almost always give you better depth and
soundstage information. A word of caution though: if you move the
speakers too far from the front wall you may lose the focus of the
image.
A problem with the soundstage could also be caused by the
recording. Try another recording if you cannot achieve what you
are trying to do. The recordings in the Genesis Loudspeaker Set-up
Procedure have all been carefully chosen, so those will be the fallback recordings to use for system set-up.
Appropriate Mid-bass/Low-bass Balance
Yet another problem is a lack of mid bass energy. In order for the
appropriate amount of mid bass energy to be present, the speakers
should be close enough together to achieve proper "coupling" of the
left and right mid-bass coupler. Coupling is desirable in the lower
frequencies from the mid-bass on down. This simply means that the
left and right drivers "work together" as opposed to working
separately.
If you find there isn't enough deep bass, your first remedy is the
BASS GAIN on the woofers. This has several limitations. First, turned
up too high, you may get some distortion on very low frequencies
or you may drive the amplifier into protection.
You may need to trade-off soundstage depth for deep bass by
pushing speakers back towards the front wall. This will increase the
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coupling of the woofers to the room. Do this procedure in small
increments (approximately half an inch at a time) and return often
to the recordings you have used to adjust the front to back depth
and soundstage properties of your system. It is easy, yet
unproductive, to go too far as you will create a boominess in the
sound.
Secondly, you may make the mid bass produced by the top of the
woofer out of proportion with the mid bass produced by the bottom
of the mid-bass coupler. This would tend to sound bloated or thick in
the mid bass regions.
Another good rule of thumb is to set the BASS GAIN for proper
midbass rather than low bass. The theory is that if the midbass is
correct, then the low bass should be very close to correct. If the
midbass is proper and the low bass is still not right, here are some
other suggestions.
A good balance between proper low bass extension and a deep
and spacious soundstage needs to be established to optimize your
new speaker's performance. This is because large space
ambience information is largely in the lowest frequencies. The
wavelength of a 20Hz soundwave is approximately 52 feet (16m),
so if you want to recreate the soundspace of a cathedral, you will
need to go lower than even 20Hz.
In order to achieve what the speaker is capable of we suggest you
focus your efforts on a proper balance of soundstage elements that
includes information beyond the left and right sides of the
speakers, front to back depth well behind the speaker, excellent
focus of instruments and voices with proper vertical information and
mid bass fill.
A Genesis loudspeaker system correctly set up, can and should
provide a soundstage that will “melt the walls” and with pinpoint
focus, the speakers disappearing completely on a recording
containing such information.
Room Treatment
No room is perfect. To optimize your sonic presentation it may be
helpful to treat your room. Here are some guidelines:
1. Front walls. This loudspeaker is a dipole and therefore
there is sound coming from both the front and the back of
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the speaker. How the front wall is treated or not treated is
important. Generally speaking, the Genesis loudspeakers
prefer a live front wall.
By these terms we mean the amount of reflection of sound.
A typical wall of glass or, brick, cement or drywall material is
a reflective surface. A heavily curtained or sound proofed
wall would be considered a "dead wall" or a non-reflective
wall. A normal thin curtain across a window causes only a
small amount of absorption.
2. Sidewalls. Because the speaker is a dipole it is less
sensitive to the sidewalls. However, as a rule of thumb, it is
a good idea to keep the speaker as far away from the
sidewalls as is practical. With this in mind, it may be helpful to
add some damping material or diffuser panels to the point of
first reflection. This is a point on the sidewalls between the
listener and the loudspeaker. It is where the sound from the
loudspeaker first hits the sidewall, then bounces to the
listener. This reflection is undesirable because it is slightly
delayed from the original sound. This point on the sidewall
can be easily determined with the help of a second person
and a mirror.
Sitting in your listening position have an assistant hold a
mirror up on the sidewall. Move the mirror until you can see
the tweeter. This is the point of first reflection. A diffuser (see
your dealer), an absorptive material or even a CD rack can
help break up this point of first reflection.
3. Rear wall. In many cases it will be unnecessary to do
anything with the wall behind your listening position.
However, you may want to experiment with diffusers or
absorbers behind you for best sound. Absorption behind the
listener is usually beneficial.
Mastering the Refinements of the system
Fine tuning an audio system is an art that will take time and
patience. It can be one of the more rewarding learning experiences
you will have in the pursuit of music and its enjoyment.
One of the best pieces of advice we can offer is that you take
advantage of the ear's ability to identify similarities in sound. This
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ability is useful in fine tuning your system because if every recording
you listen to has a similarity of sound (too much or too little of a
certain frequency for instance) then you can be fairly certain that you
have yet to perfect your set-up. Keep at it and remember to enjoy
your music as you work on perfecting your set-up.
During the design stage of Genesis loudspeakers, we rely on
hundreds and hundreds of hours of critical listening. There are
changes we can make to the crossover that we can measure, but can
hardly hear the difference. And then there are the changes that we
make that we can easily hear, but cannot measure. It is an art form as
much as a science! Setting up the audio system is the same.
If you have any questions, feel free to contact us at Genesis. Our
website is the first place that you should look to for more
information, but you are welcome to either send us an email, or just
give us a call!
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John William Strutt Lord Rayleigh (1842 – 1919)
The Technology
The Genesis 4 loudspeaker integrates a ribbon tweeter and a
ribbon midrange with a pair of dynamic mid-bass couplers and a
pair of servo-controlled woofers. Add the rear tweeter with its own
crossover, and you have a five-way loudspeaker that is a marvel in
technology. The cabinet structure is designed to manage vibrations
and resonance instead of using brute-force methods of tremendous
mass.
Design Philosophy
Nothing has changed in theoretical acoustics since Lord Rayleigh’s
original book on acoustics published in 1877. There are still only
two proper ways for a transducer to propagate sound in a room: a
point source and a line source. Anything else, or everything in
between, is a compromise.
In order for all frequencies of
sound from the loudspeaker to
reach the listener at exactly the
same time, a coherent wave front
is important - not just “time-
alignment” of drivers. The ideal is
either an infinitely small pulsating
point or a pulsating line with a size
on the order of the room
dimension.
the ideal, and in doing so, provide sufficient radiating area for
dynamically and spatially realistic sound reproduction.
The G4 is a point-source dipole loudspeaker, and hence, the
challenge during the design was to approximate an infinitesimally
small pulsating point from a 4-foot tall loudspeaker. We have
achieved this using carefully calculated crossover slopes and our
own crossover topology.
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Obviously, a line-source is much
easier to mechanize than the ideal
point source. The line-source (if
large enough), can approximate
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The G4 is also a dipole radiator with the front and rear tweeters,
midrange and mid-bass couplers are open front and back and
mounted on a light, resonance-managed baffle with no enclosure.
This has two advantages: firstly, it eliminates any enclosure or boxy
colorations caused by cabinet vibrations or resonance. Secondly,
the dipole creates a cardioid radiation pattern (like a figure-eight),
which has its maximum output at the listening position and behind
the speaker itself, and minimum output to the sides in the plane of
the loudspeakers. This very effectively minimizes the bounce from
the sidewalls resulting in fewer detail-robbing room reflections than
other types of loudspeakers. With fewer spurious reflections to
confuse your hearing, the program source emerges more clearly.
Imaging is deeper, yet more focused.
The Genesis Ring-Radiator Ribbon Tweeter
Reviewers in the audiophile press have often remarked that the
Genesis ribbon (technically, it is a planar-magnetic) tweeter is the
world’s best. It is a one inch ring-ribbon design crafted from an
extremely thin membrane of Kapton with a photo-etched aluminium
“voice coil” that is a mere 0.0005 inch thick. The entire radiating
structure is a 4mm wide ring that has less mass than the air in front
of it! That is why it will accurately reproduce frequencies with true
point-source dispersion to 40 kHz. (As comparison, a 1”
diameter dome will only have true point-source
dispersion to about 13kHz.)
The result of this design is a driver that has a rapid and
uniform response to high frequencies, and has the speed
of the best ribbon/electrostatic designs without the high
distortion and poor dispersion that is typically associated
with large, squarish ribbon tweeters. The G4 also use a
rear-firing tweeter with its own independent crossover
out of phase to the front tweeter creating a dipole.
6-inch Ribbon Midrange
We sometimes say that the midrange is a window into the mind of
a composer or a singer. And indeed, the midrange is where the
“magic” is in a well-recorded musical event. This is why the G4
uses a ribbon (technically also a planar-magnetic) for a midrange.
The midrange ribbon used in the G4 is manufactured to Genesis’
exacting specifications. The ribbon itself is made of a very thin layer
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of aluminium laminated to a substrate of mylar that is 0.001inch
thick. The ribbon is then suspended in the magnetic field created
by 5 feet of neodymium magnets.
This result in a near perfect ribbon midrange with the same wide
and even radiation characteristics as the Genesis tweeter.
Titanium Mid-Bass Coupler
The G4 uses a pair of Genesis-designed proprietary 5.5 inch solid
titanium-coned transducers to cover this critical frequency
spectrum between the midrange and the servo-bass woofers.
Manufactured out of one of the lightest and stiffest materials
known, this low mass cone driver with nearly instantaneous
transient response, enables the G4 to sound lifelike and effortless.
The stiffness of the titanium cone allows it to retain its low distortion
even on long throw application needed in delivering lower
frequencies. Hence, the solid titanium cone allowed Genesis to
develop a driver that is exemplary in the midrange, as well as
deliver the heft and impact of a woofer to “bridge the gap”.
Proprietary Crossover Topology
We believe that the crossover is the brain of the loudspeaker. In
order to manage and maximize the performance of the extensive
complement of transducers used in Genesis loudspeakers, we
spend more money on the crossover than many other
manufacturers put in their entire speaker.
Each crossover is designed by computer modeling plus years of
knowledge and experience. The inductors are custom designed
and made for Genesis with OFC copper windings. The special
film&foil capacitors used are also custom made for Genesis, using
high-quality polypropylene-film and tin-foil. The crossover of each
G4 weighs over 11 pounds (5kg)!
More importantly, the crossovers are designed with many, many
hours of music listening and constant refining, tuning and tweaking
of the circuit. Out of this comes the “magic” that is a Genesisdesigned loudspeaker system
The Servo-bass Advantage
Very few loudspeakers use servo drive, either because most
designers think that it is too difficult to design, too expensive, or
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because of the extraordinary demands a servo system makes on
the amplifier and the transducer. The history of the Genesis servosystem started from the first introduced in the legendary Infinity®
Servo Statik One in 1968(!) – so we know how to design and build
servo systems. The technology has been constantly updated and
refined over the past 40 years.
The concept of our servo bass system is an easy one to
understand: It employs an accelerometer as a sensor to constantly
monitor the movement of the woofer cone and continuously
compares it to the input signal. This comparison circuit instantly
identifies any deviation from the input and applies a corrective
signal to compensate for any deviation, resulting in the virtual
elimination of the inherent distortion of the woofer.
As an example, when you have a high-impact, low-bass signal that
starts and stops suddenly (for example a tympani), the inertia of the
woofer cone makes it slow to start moving, and then after it has
started moving, the momentum of the cone makes it continue to
move after the signal has stopped. The sonic result is softness,
overhang, and bloat in the bass. This results in a perceived lack of
tautness and definition, and a blurring of dynamic impact.
With the servo system, the circuit senses that the woofer is not
moving as fast as it should, and it instantaneously applies much
more current to make it move faster. When the signal stops, it
senses that the woofer is continuing to move when it shouldn’t be
moving and applies a counter-signal to stop the woofer faster and
more effectively than an open loop woofer could possibly respond.
Thus, the servo-drive reduces distortion and improves transient
response by making the woofer appear to be massless. Typical
non-servo woofer systems have distortion levels that exceed 10%
at even moderate levels. The Genesis servo bass system reduces
this distortion to below one percent at almost any output level. The
system also drives the woofer to constant acceleration, which
makes the frequency response of the woofer anechoically flat to
the lowest frequencies.
The Servo-controlled Woofers
The transducer used in a servo system must be strong enough to
withstand the high current approach of the servo, and yet delicate
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and light enough to react extremely quickly. The G4 features two
side-firing 10-inch woofers per channel.
While the servo system is able to ensure that the driver works
linearly as a perfect piston, it is unable to correct for distortion
caused by cone wobble, bending, and break-up. Hence, the drivers
were designed to minimize these non-linear distortions.
A pair of matched woofers are horizontally opposed and in phase
with one another, with the vibrations generated by one woofer
cancelling out the vibrations generated by the other woofer –
further reducing any image-distorting vibrations in the loudspeaker.
Servo-controlled Bass Amplifier
The servo-controlled bass is a holistic system of woofers,
acceleration sensors, servo-feedback circuits, crossover circuitry
and amplifiers. The system places extraordinary demands on the
amplifier because the system uses enormous amounts of current to
make the woofer follow the input signal. In order to deliver this
current, a Class D amplifier module is used with specially designed
and tuned Dynamic Power Delivery System (DPDS) power
supplies.
One side benefit of this powered woofer system is that almost “any”
sized amplifier can be used to drive the mid/tweeter section of the
Genesis 4. No longer must one choose between having an
amplifier with enough power to drive the woofers, and a smaller
amplifier having better spatial and tonal characters. Nevertheless,
we do recommend no less than 100 watts as a minimum for the
midbass/tweeter section due to the need to drive a pair of dynamic
5.5-inch titanium mid-bass couplers.
The Acoustic Suspension
The suspension for each loudspeaker comprises three elements:
1) The neoprene vibration absorbers are tuned to isolate and
decouple the loudspeaker cabinet for optimal imaging and
bass response no matter what surface the loudspeaker sits
on.
2) The skeletal frame acts as a tuned absorber. Made of an
inch of solid HMWA (high molecular weight cast acrylic), no
two parts of the frame will resonate at the same frequencies.
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This ensures that all midrange frequencies are “dumped”
below the base of the cabinet so that floor-borne vibrations
do not affect the imaging and soundstage of the
loudspeaker.
3) The spikes rigidly couple the suspension system to the floor.
If you have hardwood floors and do not want to make holes
in the wood, use a copper penny (instead of expensive
“spike cups”) under the spike.
A pin-point suspension system is designed to pass all
frequencies. Using a spike cup under the spike will defeat
this system. The spike passes all frequencies to the spike
cup, and then depending on the diameter of the spike cup, it
passes only frequencies below a particular frequency.
A copper penny gets deformed – the spike making an
indentation where it meets the penny, and a little “nipple” on
the other side. This still performs the same function as a pinpoint suspension system, but at the same time protects your
hardwood floor.
Nevertheless, despite the acoustic suspension, if you have a
extremely light and resonant floorboards, the acoustic suspension
may still transmit sufficient vibrations to make your floor resonate
and hence muddy up the bass and the imaging. In that case, it may
be necessary to place heavy marble, slate, or granite slabs (at
least 200lbs per slab) under the speakers. This slab serves as a
foundation on which the acoustic suspension will work.
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Specifications
Dimensions: H 50” x W 18” x D 22”
Weight: 120 lbs (55kg) each
Frequency Response: 20Hz to 40kHz, +/- 3dB
Controls: Soft/Bright (+/- 4.5 dB)
Warm/Tight (+/- 4.5 dB)
Bass Gain (1 - 11)
Low Pass (71Hz to 135Hz)
Input Impedance: 4 ohms (nominal)
Sensitivity: 89 dB/watt @ 1 meter
Amplifier Power Rating: 500W Class D
Inputs: 5-way binding posts
Finish: Custom
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