MartinLogan STAGECenter Channel Speaker Specifications

MartinLogan STAGECenter Channel Speaker Specifications
Serial Number: _________________________________
Record your serial number here for easy reference. You will need this information when filling out your warranty registration. Stage’s serial number is
located on backplate and on the shipping container.
Thank you—to you, the MartinLogan owner,
for loving what we do,
for making it possible for us to do what we love.
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Installation in Brief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
AC Power Connection
Signal Connection
Using One Power Supply. . . . . . . . . . . . . . . . . . . . . . . . . 8
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Using the Adjustable Mount
Installation Options
Rubber Bumper Feet
Mounting the Stage on a Wall . . . . . . . . . . . . . . . . . . . . 10
Home Theater. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Electrostatic Advantages . . . . . . . . . . . . . . . . . . . . . . . . 14
MartinLogan Exclusives . . . . . . . . . . . . . . . . . . . . . . . . . 15
XStat™ Transducer
CLS™ (Curvilinear Line Source)
Generation 2 Diaphragm
MicroPerf Stator
Vacuum Bonding
AirFrame™ Technology
In accordance with the European Union WEEE (Waste
Electrical and Electronic Equipment) directive effective
August 13, 2005, we would like to notify you that this
product may contain regulated materials which upon
disposal, according to the WEEE directive, require special reuse and recycling processing.
For this reason MartinLogan has arranged with our distributors in European Union member nations to collect and
The lightning bolt flash with arrowhead symbol, within
an equilateral triangle, is intended to alert the user to
the presence of uninsulated “dangerous voltage” within
the product’s enclosure that may be of sufficient magnitude to constitute a risk of electric shock.
Electrostatic History. . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Frequently Asked Questions. . . . . . . . . . . . . . . . . . . . . 18
Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Warranty and Registration
Serial Number
Dimensional Drawings . . . . . . . . . . . . . . . . . . . . . . . . . 22
On Stand
Wall Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Glossary of Audio Terms . . . . . . . . . . . . . . . . . . . . . . . . 24
Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
recycle this product at no cost to you. To find your local distributor please contact the dealer from whom you purchased this product,
email [email protected] or visit the distributor locator at www.
Please note, only this product itself falls under the WEEE directive.
When disposing of packaging and other related shipping materials we
encourage you to recycle these items through the normal channels.
The exclamation point within an equilateral triangle is
intended to alert the user to the presence of important
operating and maintenance (servicing) instructions in
the literature accompanying the appliance.
WARNING! Do not use your Stage loudspeaker outside of the country of original sale—voltage requirements vary
by country. Improper voltage can cause damage that will be potentially expensive to repair. The Stage is shipped
to authorized MartinLogan distributors with the correct power supply for use in the country of intended sale. A list
of authorized distributors can be accessed at or by emailing [email protected]
We know you are eager to hear your new MartinLogan
loudspeaker, so this section is provided to allow fast and
easy set up. Once your new speaker is operational, please
take the time to read, in depth, the rest of the information in the enclosed manual. It will give you perspective
on how to attain the greatest possible performance from
this most exacting transducer.
Step 1: Unpacking
Remove your new MartinLogan speakers from its packing.
Retain the packaging in a safe, dry place for future use.
If you should experience any difficulties in the setup or
operation of your MartinLogan speaker, please refer to
the Connections section of the user’s manual.
Step 3: Power Connection (AC) (see warning)
MartinLogan speakers require power to energize their
electrostatic panels. Using the power cords provided,
plug first to the power in receptacle on the rear panel
of the speaker, making sure that you have made a firm
connection, and then to the wall outlet. Please see the
Connections section (pages 7–8) for more details.
Should you encounter a persistent problem that cannot
be resolved, please contact your authorized MartinLogan
dealer. They will provide you with the appropriate technical analysis to alleviate the situation.
• Hazardous voltages exist inside—do not
remove cover.
• Refer servicing to a qualified technician.
• To prevent fire or shock hazard, do not
expose this module to moisture.
• Turn amplifier off and unplug speaker should
any abnormal conditions occur.
• Turn amplifier off before making or breaking
any signal connections!
• Do not operate if there is any visual damage
to the electrostatic panel element.
• Do not drive speaker beyond its rated power.
• The power cord should not be installed,
removed, or left detached from the speaker
while the other end is connected to an AC
power source.
• No candles or other sources of open flame
should be placed on the speaker.
• No liquids either in glasses or vases should be
placed on speaker.
• Speaker should not be exposed to dripping or
splashing liquids.
• The terminals marked with the lightning bolt
symbol should be connected by an instructed
person or by way of ready made terminals
• To prevent injury, this apparatus must be
securely attached to the floor/wall in accordance with the installation instructions.
Step 2: Placement
Place the speaker at the desired location. Please see the
Installation section (pages 9–11) for more details.
Step 4: Signal Connection
Use the best speaker cables you can. Higher quality cable,
available from your specialty dealer, is recommended and
will give you superior performance. Spade connectors are
suggested for optimum contact and ease of installation.
Attach your speaker cables to the Signal Input section on
the rear panel. Be consistent when connecting speaker
leads to the terminals on the back of the speaker: take
great care to assign the same color to the (+) terminal on
the speaker and the amplifier. Please see the Connections
section (pages 7–8) for more details.
Step 5: Listen and Enjoy
Installation in Brief
Congratulations! You have invested in one of the
world’s premier loudspeaker systems.
The Stage represents an advanced combination of sonic
technologies establishing an unprecedented direction for
audiophile design. The result of years of research, the new
Stage™ hybrid electrostatic loudspeaker features XStat™
technology establishing new standards for efficiency,
dynamics and precision in a loudspeaker.
Housed within an innovative AirFrame™, the Stage’s
new CLS XStat™ transducer builds upon the legacy of
MartinLogan’s electrostatic heritage with the incorporation of advanced vacuum bonding and MicroPerf stat
panels, providing even greater efficiency and precision.
Through rigorous testing, the curvilinear electrostatic
panel has proven itself to be one of the most durable and
reliable transducers available today. Fabricated from a
custom tool punched high-grade steel, the patented
panel is then coated with a special polymer that is applied
via a proprietary electrostatic bonding process. This panel
assembly houses a membrane just 0.0005 of an inch thick.
Ruggedly constructed and insulated, the panel is rated to
easily handle up to 250 watts of continuous power with
no deleterious effects.
Featuring an advanced crossover topology derived from
the Summit loudspeaker, MartinLogan engineered the
Stage™ crossover using precision audiophile-grade polypropylene capacitors and high-purity air-core coils. This
advanced crossover topology flawlessly preserves sonic
subtleties while effortlessly handling the broadest range of
The materials in your new Stage speaker are of the highest
quality and will provide years of enduring enjoyment
and deepening respect. The cabinetry is constructed from
dense composite material for acoustical integrity and features hand rubbed wood veneers.
The other sections of your User’s Manual explain in detail
the operation of your Stage speaker and the philosophy
applied to their design. A clear understanding of your
speaker will insure that you obtain maximum performance and pleasure from this most exacting transducer.
It has been designed and constructed to give you years of
trouble-free listening enjoyment.
AC Power Connection
Your Stage uses an external low-voltage power supply to
energize its electrostatic panel. For this reason the proper
low-voltage power supply is provided. The power supply
should be firmly inserted into the ‘Power In’ receptacle
on the rear connection panel of the speaker, then to any
convenient AC wall outlet (see figure 1). Your Stage integrates a signal sensing circuit which will switch the Stage
off after a few minutes of no music signal, and requires
less than two seconds to recharge the panel when a music
signal is present.
Your Stage speaker is provided with a power supply for
the power service supplied in the country of original
consumer sale. The AC power rating applicable to a particular unit is specified both on the packing carton and on
the power supply.
Connections are made at the signal input section on the
rear electronics panel of the Stage (see figure 1). Use
spade connectors for optimum contact. Make certain that
all of your connections are tight.
Be consistent when connecting speaker leads to the terminals on the back of the Stage. Take great care to assign
the same color to the (+) terminal on both the speaker
and the amplifier.
WARNING! Turn your amplifier off before making or breaking any signal connections!
If you remove your Stage speakers from the country of
original sale, be certain that the AC power supplied in any
subsequent location is suitable before connecting the lowvoltage power supply. Substantially impaired performance
or severe damage may occur to a Stage speaker if operation is attempted from an incorrect AC power source.
WARNING! The power supply should not
be installed, removed, or left detached from
the speaker while connected to an AC power
Signal Connection
Use the best speaker cables you can. The length and type
of speaker cable used in your system will have an audible
effect. Under no circumstance should a wire of gauge
higher (thinner) than #16 be used. In general, the longer the length used, the greater the necessity of a lower
gauge, and the lower the gauge, the better the sound,
with diminishing returns setting in around #8 to #12.
A variety of speaker cables are now available whose
manufacturers claim better performance than standard
heavy gauge wire. We have verified this in many cases,
and the improvements available are often more noticeable than the differences between wires of different
gauge. The effects of cables may be masked if the equipment is not of the highest quality.
Figure 1. Power and signal connection.
Using Only One Power Supply
You may have noticed a connection on the back of
your Stage labeled ‘Power Out’. The use of this connection will allow you to daisy-chain up to five low-voltage
MartinLogan products and eliminate the need for multiple
low-voltage power supplies.
A variety of low voltage interconnect cables may be purchased at your local MartinLogan dealer. Please ask them
about options to fit your specific needs.
To use this connection option choose a primary speaker
(whichever speaker is most convenient) and connect it as
instructed in the ‘Low-Voltage Power Connection’ section
on the previous page. To attach additional speakers, run a
low-voltage interconnect cable from the ‘Power Out’ to the
next speaker’s ‘Power In’ (see figure 2). Cable not included.
Figure 2. Connecting power to multiple speakers using one power supply.
When you first begin to play your Stage speaker, it will
sound a bit bass shy. This is due to the high-quality, longlife components used in our woofer. Our custom made,
butyl surround woofer requires at least 80 hours of
break-in at 90 dB (moderate listening levels) before any
critical listening. The break-in requirements of the crossover components (and, to a lesser degree, the electrostatic
transducer) are equal.
Using the Adjustable Mount
For optimum performance the Stage must be tilted on its
stand towards the main listening position and directed
towards the audience’s ears (see figure 3). After you have
placed your Stage in its final location, loosen the 2 knobs
located on the stand arm, pivot the Stage towards the
main listening position, and then re-tighten the knobs.
The stand shipped with the Stage loudspeaker is
designed for use only with the Stage. Use with
other appliances may result in instability causing
possible injury.
Installation Options
On the Television
If your television provides a wide, level and stable platform, the shielded Stage can be placed directly on top
of the television (see figure 3). For this option we recommend installation of the rubber bumper feet.
Rubber Bumper Feet
If you are using the Stage on top of your television, or setting it on any type of surface, we recommend installing the
4 rubber bumper feet included with the Stage. The Stage
ships with these 4 rubber bumper feet installed. The following instructions describe how to install the feet if they
have been previously removed for another installation.
Rubber Bumper Feet Installation Instructions:
1. Prepare a surface to work on by laying down a towel or
large soft cloth on top of a large flat surface.
2. Securely tighten the 2 knobs on the Stage stand, making sure the Stage cabinet is level with the stand.
3. Turn the Stage upside down so that the bottom of the
stand is pointing up.
4. Insert the 4 rubber bumper feet in the 4 holes on the
bottom of the stand.
On the Wall
The adjustable mount (stand) allows you to mount the
Stage on the wall (see figures 3 and “Mounting the Stage
On A Wall,” pages 10–12). If hanging the Stage on the
wall is the best placement for your system, the adjustable
mount (stand) will allow you to tilt the Stage towards the
listening position.
On the Floor
Placing the Stage on the floor might position it too low to
blend with the front speakers. (see figure 3). If placing the
Stage on the floor is the best placement for your system,
the adjustable mount (stand) will allow you to tilt the Stage
towards the listening position. For this option we recommend installation of the rubber bumper feet.
WARNING! Installation other than that
described in the body of this document requires
specific documentation from MartinLogan.
Figure 3. Stage installation on the floor, on a television and on a wall.
Mounting the Stage On A Wall
NOTE: These instructions describe how to remove the stand
from the Stage and mount it to the wall. MartinLogan recommends using 4 wall anchors and machine screws to
secure the Stage bracket to the wall. When drilling pilot
holes for the wall bracket, if any screw location hits a stud,
it is recommended to directly screw a lag bolt into the stud.
Required hardware (included):
(4) TOGGLER® SNAPTOGGLE® Toggle Bolts (Wall Anchors)
(4) 10-24 x 1.25” machine screws
(1) 1/8” Allen Tool
(2) 1/4” x 2.5” Lag Bolts (7/16” head)
(2) Flat Washers for Lag Bolts
Required tools (not supplied):
2 ft. level or a 2 ft. board and a small level
Electric drill
1/8“ drill bit
1/2“ drill bit
7/16” socket drive
Phillips screwdriver
NOTE: These instructions assume the mounting surface
is of wood frame and standard sheetrock construction. If
you wish to mount the Stage to another type of material
or construction, you should consult a bonded contractor.
Figure 4. Remove the stand from the speaker.
Prepare a flat surface with padding and sheets to protect the speaker as you work on it. Disconnect any
wires and carefully place the Stage on the work surface. Loosen the two large knobs securing the stand.
Rotate the stand back and up allowing the speaker
itself to sit directly on the surface.
Make sure that the 4 small rubber feet on the bottom
of the Stage’s metal bracket/stand are removed. If they
are not, do so at this time by gently pulling and rocking them out of the holes.
Remove the stand/wall-bracket by completely
unscrewing the two large knobs (figure 4).
WARNING! This operation requires 2 people. Do
not attempt to install your Stage by yourself
WARNING! For safety reasons, the Stage is
shipped with four small rubber feet installed on
the bottom of the metal stand. If the stand is being
mounted on a wall, these small rubber feet must
be removed.
IMPORTANT! Make sure that the four press fit
washers remain in place, two attached to the
bracket and two attached to the speaker cabinet.
Figure 5. Level the stand at the mounting location and mark the holes.
Figure 6. Drill pilot holes at the marked locations. Widen any non-stud holes.
Place the bracket against the wall at the desired location.
It is important that the entire area behind the bracket,
and 8.5 inches to the left and right of the bracket be
free from obstructions and completely flat.
IMPORTANT! If you drill into a stud during this
step, DO NOT widen the hole and DO NOT
install a toggle bolt wall anchor at this location—
you will eventually be installing a lag bolt dierctly
into the stud.
IMPORTANT! To allow the Stage to fully rotate
up or down, the following area must be free of
— 4 inches above of the bracket
— 6 inches below of the bracket
— 8.5 inches left and right of the bracket
Using a 1/8" bit, drill four pilot holes.
Use a 1/2" drill bit, widen the pilot holes so toggle bolt
wall anchors can be installed.
Using a level, square the bracket and mark the 4 hole
Figure 7. Installing a toggle bolt wall anchor.
Install TOGGLER® SNAPTOGGLE® toggle bolts at all
locations with a 1/2-inch hole. To do this:
Hold the toggle bolt metal channel flat alongside the
plastic straps. Slide the metal channel through the 1/2inch hole.
Hold the ends of the straps between thumb and forefinger and even them out. Pull the entire toggle bolt
toward you until the channel rests flush behind the
wall. Slide the plastic cap along the straps with the
other hand until the flange of the cap is flush with the
Place a thumb between the straps at the wall. Push
the thumb side to side, snapping off the straps level
with the flange.
U.S. Patent No. 6,161,999 and foreign counterparts thereof and of U.S. Patent No.
4,650,368. TOGGLER and its typeface and SNAPTOGGLE are worldwide registered trademarks of Mechanical Plastics Corp. For further technical information on these anchors, visit
Figure 8–9. Attach the stand to the wall using 4 screws. Install the Stage.
Hold the bracket at the mounting location.
Install the 10-24 x 1.25-inch machine screws in any
locations where toggle bolt wall anchors were placed.
Install a lag bolt and washer at any location where a
stud was found.
With the help of an assistant, line up the Stage speaker
with the mounted bracket and attach it using the two
large knobs.
IMPORTANT! There should be four press fit
washers—two attached to the bracket and two
attached to the speaker cabinet. When correctly
installed these washers should be flush next to each
other between the bracket and speaker cabinet.
It had long been the practice of stereo buffs to connect their
television to a stereo system. The advantage was the use of
the larger speakers and more powerful amplifier of the
stereo system. Even though the sound was greatly improved,
it was still mono and limited by the broadcast signal.
In the late 1970’s and early 1980’s two new home movie
formats became widely available to the public: VCR and
laser disc.
By 1985, both formats had developed into very high quality
audio/video sources. In fact, the sonic performance of some
video formats exceeded audio-only formats. Now, with
theater-quality sound available at home, the only element
missing was the "surround sound" presentation found in
movie houses.
Fortunately, Dolby and DTS encoded movies (including
almost all films) have the same surround sound information encoded on home releases as the theatrical release.
All that is required to retrieve this information is a decoder
and additional speakers and amps to reproduce it.
Surround Speakers
We recommend (along with the film industry) that the surround speakers play down to at least 80 Hz. Surround
speakers contain the information that makes it appear that
planes are flying over your head. Some may suggest that this
is the place to save money and purchase small, inexpensive
speakers. If you choose to do so, be prepared to upgrade
in the future as discrete multi-channel digital encoding is
proliferating rapidly and the demands on surround speakers have increased.
With any good surround system you will need one or
more high-quality subwoofers (the .1 in a 5.1, 6.1, or
7.1 channel surround system). Most movie soundtracks
contain large amounts of bass information as part of the
special effects. Good subwoofers will provide a foundation for the rest of the system.
Home theater is a complex purchase and we recommend
that you consult your local MartinLogan dealer, as they
are well versed in this subject.
Each piece of a surround system can be purchased separately. Take your time and buy quality. No one has ever
complained that the movie was too real. The following list
and descriptions will give you only a brief outline of the
responsibilities and demands placed on each speaker.
Front Left and Front Right
If these speakers will be the same two used for your stereo
playback, they should be of very high quality and able to
play loudly (over 102 dB) and reproduce bass below 80 Hz.
Center Channel
This is the most important speaker in a home theater
system, as almost all of the dialogue and a large portion
of the front speaker information is reproduced by the
center channel. It is important that the center speaker
be extremely accurate and mate well with the front
speaker, and that it is recommended for use as a center
speaker. This is not the place to cut corners.
Figure 18. Summit speakers as front channels, the Stage as the center
channel, Script i speakers as side surround (effects) channels, and Descent
subwoofers as 0.1 (effects) channel.
Home Theater
How can sound be reproduced by something that you are
able to see through? Electrostatic energy makes this possible.
Where the world of traditional loudspeaker technology
deals with cones, domes, diaphragms and ribbons that
are moved with magnetism, the world of electrostatic
loudspeaker deals with charged electrons attracting and
repelling each other.
To fully understand the electrostatic concept, some background information will be helpful. Remember when you
learned in a science or physics class that like charges repel
each other and opposite charges attract each other? Well,
this principle is the foundation of the electrostatic concept.
An electrostatic transducer consists of three pieces: stators,
the diaphragm and spacers (see figure 19). The diaphragm
is what actually moves to excite the air and create music.
The stator’s job is to remain stationary, hence the word
stator, and to provide a reference point for the moving
diaphragm. The spacers provide the diaphragm with a
fixed distance in which to move between the stators.
As your amplifier sends music signals to an electrostatic
speaker, these signals are changed into two high-voltage
signals that are equal in strength but opposite in polarity.
These high voltage signals are then applied to the stators.
The resulting electrostatic field, created by the opposing
high voltage on the stators, works simultaneously with
and against the diaphragm, consequently moving it back
and forth, producing music. This technique is known as
Figure 19. Cut away view of an XStat™ electrostatic transducer. Notice
the simplicity due to minimal parts usage.
Electrostatic Advantages
push-pull operation and is a major contributor to the sonic
purity of the electrostatic concept due to its exceptional
linearity and low distortion.
Since the diaphragm of an electrostatic speaker is uniformly driven over its entire area, it can be extremely light and
flexible. This allows it to be very responsive to transients,
thus perfectly tracing the music signal. As a result, great
delicacy, nuance and clarity is possible. When you look
at the problems of traditional electromagnetic drivers,
you can easily see why this is so beneficial. The cones and
domes which are used in traditional electromagnetic drivers cannot be driven uniformly because of their design.
Cones are driven only at the apex. Domes are driven at
their perimeter. As a result, the rest of the cone or dome
is just “along for the ride”. The very concept of these
drivers requires that the cone or dome be perfectly rigid,
damped and massless. Unfortunately, these conditions are
not available in our world today.
To make these cones and domes move, all electromagnetic drivers must use voice coils wound on formers, spider
assemblies, and surrounds to keep the cone or dome in
position (see figure 20). These pieces, when combined
with the high mass of the cone or dome materials used,
make it an extremely complex unit with many weaknesses
and potential for failure. These faults contribute to the
high distortion products found in these drivers and is a
tremendous disadvantage when you are trying to change
motion as quickly and as accurately as a loudspeaker must
(40,000 times per second!).
Figure 20. Cut away view of a typical moving coil driver. Notice the complexity due to the high number of parts.
XStat™ Transducer
XStat™ transducers incorporate a myriad of technology and
design innovations including CLS™, MicroPerf, Generation
2 Diaphragms, ClearSpars™, and Vacuum Bonding.
CLS™ (Curvilinear Line Source)
Since the beginning of audio, achieving smooth dispersion
has been a problem for all designers. Large panel transducers present unique challenge because the larger the panel,
the more directional the dispersion pattern becomes.
Wide range electrostats have long been one of the most
problematic transducers because they attain their full
range capabilities via a large surface area. It looked as if
they were in direct conflict to smooth dispersion and
almost every attempt to correct this resulted in either poor
dispersion or a serious compromise in sound quality.
After extensive research, MartinLogan engineers discovered
an elegantly simple solution to achieve a smooth pattern of
dispersion without degrading sound quality. By curving the
horizontal plane of the electrostatic transducer, a controlled
horizontal dispersion pattern could be achieved, yet the
purity of the almost massless electrostatic diaphragm
remained uncompromised. After creating this technology,
MartinLogan developed the production capability to bring
it out of the laboratory and into the market place. You will
find this proprietary MartinLogan technology used in all
of our electrostatic products. It is one of the many reasons
behind our reputation for high quality sound with practical usability. This is also why you see the unique “see
through” cylindrical shape of MartinLogan products.
Generation 2 Diaphragm
MicroPerf Stator
Sleek. Compact. MicroPerf stator technology, featured in
all XStat™ transducers, reveals more open playable area
in each panel, offering increased performance from even
more compact stat panels. It is significant to note that the
XStat™ transducer in the radical new Stage loudspeaker
supports the bandwidth and dynamics associated with
traditional electrostatic panels nearly twice its size.
Vacuum Bonding
To achieve the power, precision, and strength of the
XStat™ transducer, two insulated high-purity carbon steel
stators along with a proprietary plasma bonded diaphragm
and ClearSpar™ spacers are fused into a curved geometry
with an aerospace adhesive whose strength exceeds that
of welding. Our proprietary Vacuum Bonding process
guarantees uniform diaphragm tensioning and extremely
precise construction tolerances, resulting in unequivocal
precision, linearity and efficiency.
AirFrame™ Technology
Ultra-rigid extruded aerospace grade aluminum alloy
AirFrame™ technology rigidifies and secures the XStat™
electrostatic panel to the woofer cabinet while at the same
time providing sonic and electrical isolation. Advanced
AirFrame™ technology maximizes the electrostatic panels playable surface area and dipole dispersion pattern
while minimizing potentially acoustically destructive
intermodulated distortion caused by spurious vibrations
and resonance. The result? Ultimate imaging capability,
low-level detail resolution, improved efficiency and overall accuracy.
Stage’s diaphragm employs an extremely sophisticated
conductive coating applied to the polymer surface at an
atomic level using a plasma bonding process. A proprietary
compound is driven into the surface of the polymer film
in an oxygen free argon chamber. This process allows
extremely uniform surface resistivity characteristics, an
optically transparent surface, and a nearly massless diaphragm. This uniform surface resistivity controls the
electrostatic charge on the diaphragm surface and regulates
its migration. As a result, no discharging or “arcing” can occur.
MartinLogan Exclusives
In the late 1800’s, any loudspeaker was considered exotic.
Today, most of us take the wonders of sound reproduction
for granted.
After a short time, Rice and Kellogg had narrowed the field
of “contestants” down to the cone and the electrostat. The
outcome would dictate the way that future generations
would refer to loudspeaker as being either “conventional”
or “exotic”.
It was 1880 before Thomas Edison had invented the
first phonograph. This was a horn-loaded diaphragm
that was excited by a playback stylus. In 1898, Sir Oliver
Bell Laboratory’s electrostat was something to behold. This
Lodge invented a cone loudspeaker, which he referred to
enormous bipolar speaker was as big as a door. The diaas a “bellowing telephone”, that was very similar to the
phragm, which was beginning to rot, was made of a pig
conventional cone loudspeaker drivers that we know today.
intestine that was covered with fine gold leaf to conduct
However, Lodge had no intention for his device to reprothe audio signal.
duce music because in 1898 there was no way to amplify
When Rice and Kellogg began playing the new electrically
an electrical signal! As a result, his speaker had nothing to
cut records through the electrostat,
offer over the acoustical gramophones
they were stunned and impressed. The
of the period. It was not until 1906
Rice and Kellogg had
electrostat performed splendidly. They
that Dr. Lee DeForrest invented the
had never heard instrumental timbres
triode vacuum tube. Before this, an
narrowed the field of
reproduced with such realism. This syselectrical signal could not be amplified. The loudspeaker, as we know it “contestants down” to the tem sounded like real music rather than
the honking, squawking rendition of the
today, should have ensued then, but
acoustic gramophone. Immediately, they
it did not. Amazingly, it was almost
cone and the electrostat.
knew they were on to something big.
twenty years before this would occur.
The acoustic gramophone was destined to become obsolete.
In 1921, the electrically cut phonograph record became
Due to Rice and Kellogg’s enthusiasm, they devoted a
a reality. This method of recording was far superior to the
considerable amount of time researching the electrostatic
mechanically cut record and possessed almost 30 dB of
design. However, they soon encountered the same difdynamic range. The acoustical gramophone couldn’t begin
ficulties that even present designers face; planar speakers
to reproduce all of the information on this new disc. As a
require a very large surface area to reproduce the lower freresult, further developments in loudspeakers were needed
quencies of the audio spectrum. Because the management
to cope with this amazing new recording medium.
at Bell Labs considered large speakers unacceptable, Rice
By 1923, Bell Telephone Laboratories made the decision
and Kellogg’s work on electrostatics would never be put to
to develop a complete musical playback system consisting
use for a commercial product. Reluctantly, they advised the
of an electronic phonograph and a loudspeaker to take
Bell management to go with the cone. For the next 30 years,
advantage of the new recording medium. Bell Labs
the electrostatic design lay dormant.
assigned the project to two young engineers, C. W. Rice
and E. W. Kellogg.
During the Great Depression of the 1930’s, consumer audio
almost died. The new electrically amplified loudspeaker
Rice and Kellogg had a well equipped laboratory at their
never gained acceptance, as most people continued to
disposal. This lab possessed a vacuum tube amplifier
use their old Victrola-style acoustic gramophones. Prior to
with an unheard of 200 watts, a large selection of the
the end of World War II, consumer audio saw little, if any,
new electrically cut phonograph records and a variety of
progress. However, during the late 1940’s, audio expeloudspeaker prototypes that Bell Labs had been collecting
rienced a great rebirth. Suddenly there was tremendous
over the past decade. Among these were Lodge’s cone, a
interest in audio products, and with that, a great demand
speaker that used compressed air, a corona discharge (plasfor improved audio components. No sooner had the cone
ma) speaker, and an electrostatic speaker.
become established than it was challenged by products
developed during this new rebirth.
Electrostatic History
In 1947, Arthur Janszen, a young Naval engineer, took part
in a research project for the Navy. The Navy was interested
in developing a better instrument for testing microphone
arrays. The test instrument needed an extremely accurate
speaker, but Janszen found that the cone speaker of the
period were too nonlinear in phase and amplitude response
to meet his criteria. Janszen believed that electrostats were
inherently more linear than cones, so he built a model using
a thin plastic diaphragm treated with a conductive coating.
This model confirmed Janszen’s beliefs, for it exhibited
remarkable phase and amplitude linearity.
was very directional and its power handling was limited to
around 70 watts. As a result, many people continued to use
box speakers with cones.
In the early 1960’s Arthur Janszen joined forces with the
KLH loudspeaker company, and together they introduced
the KLH 9. Due to the large size of the KLH 9, it did not
have as many sonic limitations as the Quad. The KLH 9
could play markedly louder and lower in frequency than
the Quad ESL. Thus a rivalry was born.
Janszen continued to develop electrostatic designs. He
was instrumental in the design of the Koss Model One,
Janszen was so excited with the results that he continued
the Acoustech and the Dennesen speaker. Roger West,
research on the electrostatic speaker on his own time. He
the chief designer of the Janszen
soon thought of insulating the stators to
Corporation, became the presiprevent the destructive effects of arcing.
These developments allow
dent of Sound Lab. When Janszen
By 1952, he had an electrostatic
tweeter element ready for commercial
the consumer to own the
Corporation was sold, the RTR
production. This new tweeter soon
loudspeaker company bought
created a sensation among American
highest performance loud- half of the production tooling. This
audio hobbyists. Since Janszen’s
tooling was used to make the electweeter element was limited to high speaker products ever built. trostatic panels for the Servostatic, a
frequency reproduction, it often found
hybrid electrostatic system that was
itself used in conjunction with woofers—most notably,
Infinity’s first speaker product. Other companies soon
those from Acoustic Research. These systems were highly
followed; each with their own unique applications of
regarded by all audio enthusiasts.
the technology. These include Acoustat, Audiostatic,
Beverage, Dayton Wright, Sound Lab and Stax, to name a few.
As good as these systems were, they would soon be surpassed
by another electrostatic speaker.
Electrostatic speakers have progressed and prospered
because they actually do what Peter Walker claimed they
In 1955, Peter Walker published three articles regarding
would. The limitations and problems experienced in the
electrostatic loudspeaker design in Wireless World, a British
past were not inherent to the electrostatic concept. They
magazine. In these articles, Walker demonstrated the benefits
were related to the applications of these concepts.
of the electrostatic loudspeaker. He explained that electrostatics permit the use of diaphragms that are low in mass,
Today, these limitations have been resolved. Advancements
large in area and uniformly driven over their surfaces by
in materials due to the U.S. space program give designers
electrostatic forces. Due to these characteristics, electrostats
the ability to harness the superiority of the electrostatic
have the inherent ability to produce a wide bandwidth,
principle. Today’s electrostats use advanced insulation
flat frequency response with distortion products being no
techniques or provide protection circuitry. The poor disgreater than the electronics driving them.
persion properties of early models have been addressed by
using delay lines, acoustical lenses, multiple panel arrays or,
By 1956, Walker backed up his articles by introducing a
as in our own products, by curving the diaphragm. Power
consumer product, the now famous Quad ESL. This speaker
handling and sensitivity have also been increased.
immediately set a standard of performance for the audio
industry due to its incredible accuracy. However, in actual
These developments allow the consumer the opportunity
use, the Quad had a few problems. It could not be played
to own the highest performance loudspeaker products ever
very loud, it had poor bass performance, it presented a difbuilt. It’s too bad Rice and Kellogg were never able to see
ficult load that some amplifiers did not like, its dispersion
just how far the technology would be taken.
Electrostatic History
How do I clean my speaker?
Use a dust free cloth or a soft brush to remove the dust
from your speaker. We also recommend a specialty
cloth (available at the Xtatic shop at www.martinlogan.
com) that cleans your speaker better than anything else
we have tried. For the wood surfaces it is acceptable to
slightly dampen the cloth. Do not spray any kind of
cleaning agent on or in close proximity to the electrostatic element. Avoid the use of ammonia based
products or silicone oil on the wood parts.
What is the advantage of ESL?
Since the diaphragm is uniformly driven over its entire
surface—unlike a tweeter that is only driven at its
edges— it is the only technology that can be made
large enough to play bass, yet is still light enough for
high frequencies. This unique property allows for the
elimination of high frequency crossover points and
their associated distortions.
What size amplifier should I use?
We recommend an amplifier with 100 to 250 watts
per channel for most applications. Probably less would
be adequate for our smaller hybrids or when used in
home theater where a subwoofer is employed. Our
hybrid designs will perform well with either a tube or
transistorized amplifier, and will reveal the sonic character of either type. However, it is important that the
amplifier be stable operating into varying impedance
loads: an ideally stable amplifier will typically be able
to deliver nearly twice its rated wattage into 4 Ohms
and should again increase into 2 Ohms.
Could you suggest a list of suitable electronics and
cables that would be ideal for MartinLogan speakers?
The area of electronics and cable choice is probably
the most common type of question that we receive. It
is also the most subjective. We have repeatedly found
that brands that work well in one setup will drive
someone else nuts in another. We use many brands
with great success. Again, we have no favorites; we
use electronics and cables quite interchangeably. We
would suggest listening to a number of brands—and
above all else— trust your ears. Dealers are always the
best source for information when purchasing additional
audio equipment.
Frequently Asked Questions
Is there likely to be any interaction between my speaker
and the television in my Audio/Video system?
Actually, there is less interaction between a television
and an electrostatic speaker than between a television
and a conventional system. However, we do recommend
that you keep your speaker at least one foot away from
the television because of the dynamic woofer they
employ. In the case of our center channel speakers,
however, they are fully shielded and can go anywhere.
Will my electric bill go ‘sky high’ by leaving my speaker
plugged in all the time?
No. A pair of MartinLogans will draw about 8 watts
maximum (idle). There is circuitry to turn off the static
charge when not in use; however, actual consumption
will remain close to the same. The primary purpose of
the sensing circuitry is to prevent dust collection on the
electrostatic element.
If the diaphragm is punctured with a pencil or similar
item, how extensive would the damage to the speaker be?
Our research department has literally punctured hundreds
of holes in a diaphragm, neither affecting the quality of
the sound nor causing the diaphragm to rip. However,
you will be able to see the actual puncture and it can
be a physical nuisance. If this is the case, replacing the
electrostatic transducer will be the only solution.
Will exposure to sunlight affect the life or performance
of my speaker?
We recommend that you not place any loudspeaker
in direct sunlight. The ultraviolet (UV) rays from the
sun can cause deterioration of grill cloth, speaker cones,
etc. Small exposures to UV will not cause a problem.
In general, the filtering of UV rays through glass will
greatly reduce the negative effects on the electrostatic
membrane itself.
Will excessive smoke or dust cause any problems with
my electrostatic speakers?
Exposure to excessive contaminants such as smoke
or dust may potentially affect the performance of the
electrostatic membrane, and may cause discoloration
of the diaphragm membrane. When not in use for
extended periods, you should unplug the speakers and
cover them with the plastic bags in which the speakers
were originally packed. It is a good idea to vacuum the
electrostatic portion of each speaker three or four times
a year. See the vacuuming FAQ.
A problem has recently developed with my MartinLogan
speakers. The right speaker seems to be hissing even
when the amplifier and such are not connected. I was
wondering if this sounds like any problem you have
encountered previously and have a simple solution for
or might it be something which will need to be looked
into more carefully.
Your speakers are dusty. See the vacuuming FAQ. The
electrostatic charge on the element has attracted airborne
dust or pollen. Since 1993, all of our speakers have been
built with a charging circuit board that only charges the
electrostatic element when music plays. At other times
they are not charged and cannot collect dust. You can
get the same benefit by simply unplugging them whenever they are not in use. A power strip is an easy way to
do that.
Could my children, pets, or myself be shocked by the
high-voltage present in the electrostatic panel?
No. High voltage with low current is not dangerous. As
a matter of fact, the voltage in our speakers is 10 times
less than the static electricity that builds up on the surface
of your television screen.
How do MartinLogan speakers hold up over a long term
in the humidity of tropical climates?
We should tell you that MartinLogan indeed has a very
substantial number of customers in tropical regions of
the world. Our speakers have been serving them nicely
for many years. This concern may have come from our
earlier design of speakers, which were charged continuously. Since 1993, all of our speakers have been designed
so that they only charge the panel while music is being
played. This improvement has made a tremendous difference in the consistent performance of our product.
There may be a little more maintenance involved in
humid regions when not in an air conditioned environment. Simply enough, the concern is to keep the
electrostatic panels dust free. Humidity will combine
with any dust on the panel to make it slightly conductive. This will result in a slight pathway for the charge
to leave the membrane of the speakers. The solution is
simple. They only require occasional vacuuming with a
strong vacuum hose.
How do I vacuum my MartinLogan speakers?
Vacuuming will be most effective if the speakers have
been unplugged for six hours to twelve hours (or overnight). You need not worry about the vacuum pressure
damaging the "delicate" membrane. It is extraordinarily durable. Dirt and dust may be vacuumed off with
a brush attachment connected to your vacuum cleaner,
or you may blow them off with compressed air. When
vacuuming or blowing off your panels do so to both
sides, but focus the majority of your attention on the
front of the panels.
Should I unplug my speakers during a thunderstorm?
Yes, or before. It’s a good idea to disconnect all of your
audio/video components during stormy weather.
Frequently Asked Questions
No Output
• Check that all your system components are turned on.
• Check your speaker wires and connections.
• Check all interconnecting cables.
• Try hooking up a different speaker. The lack of output
could point to a problem with other equipment in your
system (amp, pre-amp, processor, etc.)
Weak or no Output from Electrostatic Panel, Loss of Highs
• Check the power cord. Is it properly connected to the
speaker and to the wall?
• Is the power cord connected to a switched outlet?
• Dirt and dust may need to be vacuumed off. Please see
the FAQ regarding vacuuming.
• Check the binding posts. Are the dirty? If so clean them
with rubbing alcohol.
• Check the binding posts. Are the loose? Make sure they
are firmly hand-tightened.
• Has a foreign substance (such as a household cleaning
chemical or soap) been applied to the panel? If so the
speaker will require servicing.
Popping and Ticking Sounds, Funny Noises
• These occasional noises are harmless and will not hurt
your audio system or your speaker. All electrostatic
speakers are guilty of making odd noises at one time or
another. It is the result of airborne contaminates (most
notably dust). Vacuuming is recommended.
• These noises may be caused by dirt and dust particles
collecting on the speaker, by high humidity.
• Dirt and dust may need to be vacuumed off. Please see
the FAQ regarding vacuuming.
Muddy Bass
• Possibly means low electrostatic panel output. See
'Weak Output from Electrostatic Panel, Loss of Highs’.
Lack of Bass, No Bass
• Check your speaker wires. Is the polarity correct?
• Check the binding posts. Are the dirty? If so clean them
with rubbing alcohol.
• Check the binding posts. Are the loose? Make sure they
are firmly hand-tightened.
Poor Imaging
• Check the polarity of the speaker wires. Are they connected properly?
• Are your speakers set up in an L-shaped room? If so,
you may experience off-center imaging. Talk to your
dealer about acoustical room treatment options.
System Frequency Response
69–22,000 Hz ± 3db
Horizontal: 30 Degrees
90 dB/2.83 volts/meter
Nominal: 4 ohms
Minimum: 2.9 ohms
Crossover Frequency
450Hz, 2700Hz
Custom-wound toroidal audio transformer, air core coils,
polypropylene capacitors
Warranty and Registration
Your Stage speaker is provided with an automatic Limited
90 Day Warranty coverage. You have the option, at no
additional charge, to receive a Limited 5 Year Warranty
coverage. To obtain the Limited 5 Year Warranty coverage you need to complete and return the Certificate of
Registration, included with your speaker, and provide a
copy of your dealer receipt, to MartinLogan within 30 days
of purchase. For your convenience MartinLogan also offers
online warranty registration at
MartinLogan may not honor warranty service claims unless
we have a completed Warranty Registration card on file!
If you did not receive a Certificate of Registration with
your new Stage speaker you cannot be assured of having
received new units. If this is the case, please contact your
authorized MartinLogan dealer.
Serial Number
Stage’s serial number is located near the binding posts.
Tweeter Type
1” (2.5 cm) neodymium soft dome
Woofer Type
Two 6.5” (16.5 cm) cast basket, aluminum cone with
extended throw driver assembly, non-resonant asymmetrical chamber format
Power Handling
250 watts
39 lbs. each (17.7 kg)
Size (with mounting bracket / stand beneath speaker)*
12” h × 34.6” w × 10.3” d
(30.4 h × 87.9 w × 26.1 d cm)
Size (with mounting bracket / stand behind speaker)*
9.3” h × 34.6” w × 11.8” d
(23.6 h × 87.9 w × 30 d cm)
Size (without mounting bracket)*
9” h × 34.6” w × 10.3” d
(22.7 h × 87.9 w × 26.1 d cm)
Should you be using your MartinLogan product in a country
other than the one in which it was originally purchased,
we ask that you note the following:
1 The appointed MartinLogan distributor for any given
country is responsible for warranty servicing only on
units distributed by or through it in that country in
accordance with its applicable warranty.
2 Should a MartinLogan product require servicing in
a country other than the one in which it was originally purchased, the end user may seek to have repairs
performed by the nearest MartinLogan distributor, subject to that distributor’s local servicing policies, but all
cost of repairs (parts, labor, transportation) must be
borne by the owner of the MartinLogan product.
3 If, after owning your speaker for six months, you
relocate to a country other than the one in which
you purchased your speaker, your warranty may be
transferable. Contact MartinLogan for details.
*Specifications are subject to change without notice.
*For detailed dimensional drawings, please see pages 24–25.
General Information
Dimensions: On Stand (stand/bracket beneath speaker)
Plan View (Top)
Front Elevation
(no stand/bracket rotation)
AC &
Side Elevation
Dimensions: No Rotation
Dimensional Drawings
Max. Dimensions: Rotated Down
Max. Dimensions: Rotated Up
Dimensions: Wall Mounting (stand/bracket behind speaker)
Plan View (Top)
Front Elevation
(no stand/bracket rotation)
AC &
Side Elevation
Dimensions: No Rotation
Max. Dimensions: Rotated Down
Max. Dimensions: Rotated Up
Dimensional Drawings
AC. Abbreviation for alternating current.
DC. Abbreviation for direct current.
Active crossover. Uses active devices (transistors, IC’s,
tubes) and some form of power supply to operate.
Diffraction. The breaking up of a sound wave caused by
some type of mechanical interference such as a cabinet
edge, grill frame or other similar object.
Amplitude. The extreme range of a signal. Usually measured
from the average to the extreme.
Diaphragm. A thin flexible membrane or cone that vibrates
in response to electrical signals to produce sound waves.
Arc. The visible sparks generated by an electrical discharge.
Bass. The lowest frequencies of sound.
Bi-Amplification. Uses an electronic crossover, or linelevel passive crossover, and separate power amplifiers for
the high and low frequency loudspeaker drivers.
Distortion. Usually referred to in terms of total harmonic
distortion (THD) which is the percentage of unwanted
harmonics of the drive signal present with the wanted signal.
Generally used to mean any unwanted change introduced
by the device under question.
Driver. See transducer.
Capacitance. That property of a capacitor which determines
how much charge can be stored in it for a given potential
difference between its terminals, measured in farads, by
the ratio of the charge stored to the potential difference.
Capacitor. A device consisting of two or more conducting
plates separated from one another by an insulating material
and used for storing an electrical charge. Sometimes called
a condenser.
Clipping. Distortion of a signal by its being chopped off. An
overload problem caused by pushing an amplifier beyond
its capabilities. The flat-topped signal has high levels of harmonic distortion which creates heat in a loudspeaker and
is the major cause of loudspeaker component failure.
Dynamic Range. The range between the quietest and the
loudest sounds a device can handle (often quoted in dB).
Efficiency. The acoustic power delivered for a given electrical input. Often expressed as decibels/watt/meter
ESL. The abbreviation for electrostatic loudspeaker.
Headroom. The difference, in decibels, between the peak
and RMS levels in program material.
Hybrid. A product created by the marriage of two different
technologies. Meant here as the combination of a dynamic
woofer with an electrostatic transducer.
CLS. The abbreviation for curvilinear linesource.
Crossover. An electrical circuit that divides a full bandwidth signal into the desired frequency bands for the
loudspeaker components.
dB (decibel). A numerical expression of the relative loudness of a sound. The difference in decibels between two
sounds is ten times the Base 10 logarithm of the ratio of
their power levels.
Glossary of Audio Terms
Hz (Hertz). Unit of frequency equivalent to the number of
cycles per second.
Imaging. To make a representation or imitation of the original
sonic event.
Impedance. The total opposition offered by an electric
circuit to the flow of an alternating current of a single frequency. It is a combination of resistance and reactance and
is measured in ohms. Remember that a speaker’s impedance changes with frequency, it is not a constant value.
Inductance. The property of an electrical circuit by which
a varying current in it produces a varying magnetic field
that introduces voltages in the same circuit or in a nearby
circuit. It is measured in henrys.
Inductor. A device designed primarily to introduce inductance into an electrical circuit. Sometimes called a choke
or coil.
Linearity. The extent to which any signal handling process
is accomplished without amplitude distortion.
Midrange. The middle frequencies where the ear is the
most sensitive.
Passive crossover. Uses no active components (transistors,
IC’s, tubes) and needs no power supply (AC, DC, battery)
to operate. The crossover in a typical loudspeaker is of the
passive variety. Passive crossovers consist of capacitors,
inductors and resistors.
Resistor. A device used in a circuit to provide resistance.
Resonance. The effect produced when the natural vibration frequency of a body is greatly amplified by reinforcing
vibrations at the same or nearly the same frequency from
another body.
Sensitivity. The volume of sound delivered for a given
electrical input.
Stator. The fixed part forming the reference for the moving
diaphragm in a planar speaker.
THD. The abbreviation for total harmonic distortion. (See
TIM. The abbreviation for transient intermodulation distortion.
Transducer. Any of various devices that transmit energy
from one system to another, sometimes one that converts
the energy in form. Loudspeaker transducers convert electrical energy into mechanical motion.
Phase. The amount by which one sine wave leads or lags
a second wave of the same frequency. The difference is
described by the term phase angle. Sine waves in phase
reinforce each other; those out of phase cancel.
Transient. Applies to that which lasts or stays but a short
time. A change from one steady-state condition to another.
Pink noise. A random noise used in measurements, as it
has the same amount of energy in each octave.
Tweeter. A small drive unit designed to reproduce only
high frequencies.
Polarity. The condition of being positive or negative with
respect to some reference point or object.
Wavelength. The distance measured in the direction of
progression of a wave, from any given point characterized
by the same phase.
RMS. Abbreviation for root mean square. The effective value
of a given waveform is its RMS value. Acoustic power is
proportional to the square of the RMS sound pressure.
White noise. A random noise used in measurements, as it
has the same amount of energy at each frequency.
Resistance. That property of a conductor by which it opposes
the flow of electric current, resulting in the generation of
heat in the conducting material, usually expressed in ohms.
Woofer. A drive unit operating in the bass frequencies only.
Drive units in two-way systems are not true woofers but
are more accurately described as being mid/bass drivers.
Glossary of Audio Terms
WARNING! Do not use your Stage loudspeaker outside of the country of original sale—voltage requirements vary
by country. Improper voltage can cause damage that will be potentially expensive to repair. The Stage is shipped
to authorized MartinLogan distributors with the correct power supply for use in the country of intended sale. A list
of authorized distributors can be accessed at or by emailing [email protected]
Lawrence, Kansas, USA
tel 785.749.0133
fax 785.749.5320
©2006 MartinLogan. All rights reserved.
Rev. #031606
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