MartinLogan | STAGECenter Channel Speaker | Specifications | MartinLogan STAGECenter Channel Speaker Specifications

THEATER
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CONTENTS
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Installation in Brief . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
AC Power Connection
Signal Connection
Break-In
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Using the Adjustable Mount
Installation Options
Rubber Bumper Feet
Stand Removal and Installation . . . . . . . . . . . . . . . . . . .7
Removing the Stand
Installing the Stand
Mounting the Theater On A Wall . . . . . . . . . . . . . . . . . .8
About the Wall Anchors
Mounting the Theater
2
Contents
Dispersion Interactions . . . . . . . . . . . . . . . . . . . . . . . . .11
Controlled Horizontal Dispersion
Controlled Vertical Dispersion
Three Major Types of Dispersion
Home Theater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Electrostatic Advantages . . . . . . . . . . . . . . . . . . . . . . . .14
MartinLogan Exclusives . . . . . . . . . . . . . . . . . . . . . . . . .15
Curvilinear Line Source
Transducer Integrity
Vapor Deposited Film
Controlled Dispersion Array
Electrostatic Loudspeaker History . . . . . . . . . . . . . . . .16
Frequently Asked Questions . . . . . . . . . . . . . . . . . . . . .18
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Specifications
Warranty and Registration
Service
Glossary of Audio Terms . . . . . . . . . . . . . . . . . . . . . . . .22
INSTALLATION
We know you are eager to hear your new Theater center
channel, so this section is provided to allow fast and easy
set up. Once you have it operational, please take the time to
read, in depth, the rest of the information in this manual. It
will give you perspective on how to attain the greatest
possible performance from this most exacting transducer.
If you should experience any difficulties in the setup or
operation of your Theater speaker, please refer to the
Operation or Installation sections of this manual.
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.
WARNING!
•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
•Do not operate if there is any visual
damage to the electrostatic panel element
•Do not over drive speaker beyond its rated power
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.
IN
BRIEF
Step 1: Unpacking
Remove your new Theater speaker from the packing.
Step 2: Placement
Place the Theater directly between your front left and
right speakers and point it directly at the listening position.
Please see the Installation section (page 6) of this manual
for more details.
Step 3: Power Connection (AC) (see warning)
MartinLogan speakers require AC power to energize their
electrostatic cells. Using the AC power cords provided,
plug the Theater in first to the AC power 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
Operations section (pages 5) of this manual for more details.
Step 4: Signal Connection
Use the best speaker cables you can. Higher quality cables,
available from your specialty dealer, are recommended
and will give you superior performance. Spade connectors
are suggested for optimum contact.
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 Theater: take great
care to assign the same color to the (+) terminal on both
the speaker and the amplifier. Please see the Operations
section (pages 5) of this manual for more details.
Step 5: Listen and Enjoy
Now, you may turn on your system and enjoy!
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.
Installation in Brief
3
INTRODUCTION
Congratulations! You have invested in a new world of
home theater!
The MartinLogan Theater represents the culmination of an
intensive, dedicated group research program directed
toward establishing a world class reference monitor
utilizing leading-edge technology, without compromising
durability, reliability, craftsmanship or aesthetic design.
The advantages of MartinLogan hybrid technology will
present themselves to you from the moment the movie
begins. The box effect (a phenomenon similar to cupping
your hand around your mouth when speaking) produced
by dynamic midrange drivers is absent and the natural
openness of the human voice comes through. Never before
in home theatre has the midrange been so clear. Sounds float
around the screen clearly defining the area from where
they were created, not the area of the speaker that created
them. This superior performance is made possible through
the use of our proprietary curved electrostatic transducer.
This is the same design technology that is used in the
state-of-the-art MartinLogan Loudspeaker Systems.
The materials in your new Theater speaker are of the highest
quality and will provide years of enduring enjoyment and
deepening respect. The cabinetry is constructed from the
highest quality composite material for acoustical integrity and
is finished with our attractive custom matte finish.
4
Introduction
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
deposition process. This panel assembly houses a membrane
just 0.0005 of an inch thick. Ruggedly constructed and
insulated, as much as 200 watts of continuous power has
driven the Theater’s energized diaphragm into massive
excursions with no deleterious effects.
The other sections of your User’s Manual will explain in
detail the operation of your Theater speaker and the philosophy
applied to their design. A clear understanding of your
speakers 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.
OPERATION
AC Power Connection
Because your MartinLogan Theater uses an internal power
supply to energize its electrostatic cells with high-voltage
DC, it must be connected to an AC power source. For this
reason it is provided with the proper IEC standard
power cord. This cords should be firmly inserted into the
AC power receptacles on the rear connection panel of the
speaker, then to any convenient AC wall outlet. The Theater
integrates a signal sensing power supply which will switch
off after a few minutes of no music signal, and requires
less than two seconds to recharge the panels when a
music signal is present.
Your Theater speaker is wired 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 serial number plate attached to
the speaker.
If you remove your Theater speaker from the country of
original sale, be certain that AC power supplied in any
subsequent location is suitable before connecting and
operating the speakers. Substantially impaired performance
or severe damage may occur to the Theater speaker if operation is attempted from an incorrect AC power source.
WARNING! 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.
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 over 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.
We also recommend, if possible, that short runs of speaker
cable connect the power amplifier and speaker and that
high quality long interconnect cables be used to connect
the preamplifier and power amplifier. This results in the
power amplifiers being close to the speakers, which may
be practically or cosmetically difficult, but if the length of
the speaker cables can be reduced to a few meters, sonic
advantages may be obtained.
Connections are done at the Signal Input section on the
rear electronics panel of the Theater (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 Theater: 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!
Break-In
When you first begin to play your Theater speaker, it will
sound a bit bass shy. This is due to the high-quality, long-life
components used in our woofer. Our custom made, butyl
surround woofer requires at least 30 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.
speaker output
THEATER
Center Channel
Amplifier
TM
Speaker
Input
Figure 1. Speaker cable connection on rear panel of the Theater.
Operation
5
INSTALLATION
Using the Adjustable Mount
For optimum performance the Theater must be tilted on
its stand towards the main listening position and directed
towards the audiences ears (see figure 3). After you have
placed your Theater in its final location, loosen the 2 knobs
located on the stand arm, pivot the Theater towards the
main listening position, and then re-tighten the knobs.
Installation Options
On the Television
If your television provides a wide, level and stable platform,
the shielded Theater can be placed directly on top of the
television (see figure 3). For this option we recommend
installation of the rubber bumper feet.
On the Wall
The adjustable mount (stand) allows you to mount the
Theater on the wall (see figures 3 and “Mounting the
Theater On A Wall,” pages 8–10). If hanging the Theater
on the wall is the best placement for your system, the
adjustable mount (stand) will allow you to tilt the Theater
towards the listening position.
On the Floor
Placing the Theater on the floor will position it too low to
blend with the front speakers. (see figure 3). If placing the
Theater on the floor is the best placement for your system,
the adjustable mount (stand) will allow you to tilt the
Theater towards the listening position. For this option we
recommend installation of the rubber bumper feet.
Rubber Bumper Feet
If you are using the Theater on top of your television, or
setting it on any type of surface, we recommend installing
the 5 rubber bumper feet included with the Theater.
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 theater stand arm,
making sure the Theater cabinet is level with the stand.
3. Turn the Theater upside down so that the bottom of the
stand is pointing up.
4. Insert the 5 rubber bumper feet in the 5 outer holes (see
figure 2).
Figure 2. The Theater stand, shown from the bottom, with bumper
insertion locations shown.
WARNING! Installation other than that
described in the body of this document requires
specific documentation from MartinLogan.
Figure 3. Theater installation on the floor, on the television, and on the wall.
6
Installation
STAND REMOVAL
NOTE: The Theater is intended to be used with its stand
attached in almost all installation options. Stand Removal and
Installation instructions are provided in case you are using a
custom installation that does not require the use of the stand.
Removing the Stand
1. Support the Theater body by placing the shipping foam
on both ends of the speaker, or setting a stack of books
beneath both ends of the speaker cabinet. The mount
should hang down from the Theater and contact the
surface of your table or floor (see figure 4, step A).
2. Before beginning to remove the mount screws, please
note that the mount is held in place with 8 screws connected to 4 brackets. These 4 brackets are attached to the
Theater cabinet. Do not remove these brackets from the
Theater cabinet. To detach the mount, remove 2 screws
from each of the 4 brackets (see figure 4, step B).
AND INSTALLATION
3. To remove the stand, simply pull it back, away from the
Theater cabinet (see figure 4, step C).
Installing the Stand
1. Support the Theater body by placing the shipping foam
on both ends of the speaker, or setting a stack of books
beneath both ends of the speaker cabinet. The speaker
cabinet should be raised high enough that when the
stand is moved into place, it can rest on the surface of
the table or floor (see figure 4, step A).
1. Carefully slide the stand into place so that it aligns with
the 4 brackets already attached to the Theater cabinet
(see figure 4, step C).
3. Insert and tighten 2 screws into each of the 4 brackets
(see figure 4, step B).
Figure 4. Stand removal and installation.
Stand Removal and Installation
7
MOUNTING
THE
THEATER ON A WALL
Mounting the Theater
WARNING! Installing the Theater on the wall
requires 2 people. Do not try this alone.
Mounting the Theater on a wall requires a minimum use of 1 lag bolt sunk directly into a stud
and 2 wall anchors. If you are able to engage
more than 1 stud with a lag bolt when mounting
the Theater on a wall we highly recommend
doing so (see figure 8).
NOTE: To assure that your Theater is safely wall mounted,
these instructions must be carefully followed. Study them
thoroughly before beginning to install your Theater.
NOTE: The following instructions assume the mounting
surface is of standard wood frame and standard sheet rock
construction. If you wish to mount the Theater to another
type of material, you should consult a bonded contractor.
About the Wall Anchors
When using the special wall anchors provided with the
Theater, it is recommended that they are sunk into the
wall by hand and not by using an electric screwdriver (see
figure 5, step 1). Once the special self-drilling wall anchors
(provided with the Theater) have been set into the wall,
they work as follows: after the screw has been inserted
approximately 1/2 inch into the wall anchor, the screw will
hit a seal that requires slight pressure to break. Once the
seal has broken, the screw will continue to slide into the
wall anchor another 11/2 inch. At this point the screw will
have rotated the anchor out and into position inside of
your wall (see figure 5, step 2 and 3). The screw will now
require slight pressure to engage the anchor. When the
anchor has been engaged, the screw will continue to slide
into the wall anchor until it is flush (see figure 5, step 4).
You will notice however that the screw continues to freely
turn at this point. The screw is now pulling the anchor up
against the back of the drywall. The screw will tighten and
stop turning when it has securely engaged the anchor with
the back of the drywall (see figure 5, step 5).
8
Mounting the Theater On A Wall
Required Tools (not included):
24 inch (60 cm) or longer ruler, level, pencil, electric drill,
1/8 inch (3 mm) drill bit, Phillips head bit, 7/16 inch (11 mm)
socket wrench, #2 Phillips head screw driver
Required Hardware (included, see figure 7):
(2) wall anchors, (2) Z-brackets, (2) 21/ 8 inches (5.4 cm) sheet
metal Phillips head screws, (2) lag bolts, (4) washers
1. Locate and mark the center point (point A, see figure 9)
where you would like to position the top of the Theater.
Measure 24 inches (61 cm) horizontally in each direction
from the center point. This area should be clear of any
obstructions in order to mount the Theater. Also make
certain that there will be at least 12 inches (30.5 cm) of
clearance above or below in order to access the knobs
and tilt the speaker up and down.
2. Using a level, vertically measure down 23/8 inches (6 cm)
from point A and mark this point (point B, see figure 9).
Next, measure horizontally to the left of point B a minimum
of 23/4 inches (7 cm) and mark the nearest stud or put a
mark at 13 inches (33 cm), whichever comes first (point C,
see figure 9). Repeat the same to the right of point B
(point D, see figure 9). Pre-drill holes at points C and D
with a 1/8 inch (3 mm) size drill bit.
3. If point(s) C and/or D are on a stud:
Using a 7/16 inch (11 mm) socket, attach a Z-bracket to
point(s) C and/or D with a lag bolt, making sure that the
bolt engages the stud. Make sure that the Z-bracket is
snug to the wall, but not overly tightened (see figure 6).
If point(s) C and/or D are not on a stud:
Using a #2 Phillips screwdriver, drive a wall anchor into
point(s) C and/or D. Next, attach a Z-bracket by sinking
a 21/8 inch (5.4 cm) sheet metal Phillips head screw and
washer into the wall anchor (see "About the Wall Anchors"
and figure 5). Make sure that the Z-bracket is snug to
the wall, but not overly tightened.
NOTE: When the Z-bracket is properly installed on a wall,
its thickest half should hang down, and its thinner half
should point up. The bend at the top of the Z-bracket
should point away from the wall.
Figure 7. Hardware included with the Theater.
Figure 5. Using the wall anchors for points C and D. Side view.
Figure 6. Using the lag bolt for points C and D. Side view.
Figure 8. The Theater mounted in various stud configurations. Front View.
Please note, to simplify this illustration, the stand is shown without the
Theater attached. When mounting the Theater, the stand should not be
removed. The Lag Bolts, Walls, and Z-Brackets are also exaggerated in size
to make this illustration easier to read.
Mounting the Theater On A Wall
9
4. Using a level, vertically measure down from point B
41/16 inches (10.3 cm) and mark this point (point E, see
figure 9).
7. For this step you may need to loosen the knobs on the
stand arm, pivot the speaker enough that you can access
the lower center point, and re-tighten the knobs.
5. If point E is on, or horizontally within 21/2 inches
(6.3 cm) of a stud:
Using a level, mark a point (point F, see figure 9) horizontal to Point E on the stud that is within 21/2 inches
(6.3 cm) of point E. Next, pre-drill a hole at point F with
a 1/8 inch (3mm) size drill bit.
If point E is on, or horizontally within 21/2 inches
(6.3 cm) of a stud:
Using a 7/16 inch (11 mm) socket, sink a lag bolt and a
washer into point F, making sure that the bolt engages
the stud (see figure 6).
21/2
If point E is not within
inches (5 cm) of a stud:
Using a #2 Phillips screwdriver, drive a wall anchor into
the wall at point E (see figure 5, step 1).
6. With the Theater mount sitting on a flat surface, loosen
the knobs on the stand arm and pivot the Theater on
the stand so that the front of the speaker is facing up.
Re-tighten the knobs. With the help of a second person,
lift the speaker up, and rotate it (mount and all) so that the
mount is parallel to the wall. Hang the Theater on the
Z-brackets and position the speaker so that point E (or F)
lines up with the long hole in the stand, above the cutout MartinLogan zig logo. The second person should
continue to support the speaker once it is in place. At this
point the Theater and mount can be carefully slid to
the left or right to fine tune its position.
If point E is not within 21/2 inches (6.3 cm) of a stud:
Using a short handled Phillips screwdriver or electric
drill, sink a 21/8 inch (5.4 cm) sheet metal Phillips head
screw and washer into the wall anchor at point E (see figure 5 and "About the Wall Anchors" on page 8).
8. Securely tighten all of the lag bolts and screws. The second
person may now release the Theater.
9. To direct the speaker to the desired listening position,
support the Theater with one hand, slightly loosen the
knobs on either side of the stand arm, and rotate the
Theater to its desired listening position. Securely re-tighten
both knob.
Figure 9. Measurements and point locations required to mount the Theater. Please note, to simplify this illustration, the stand is shown without the Theater
attached. When mounting the Theater, the stand should not be removed.
10
Mounting the Theater On A Wall
DISPERSION INTERACTIONS
Controlled Horizontal Dispersion
The convex electrostatic panel launches a 30 degree dispersion pattern when viewed from above. This horizontal
dispersion field gives you a choice of good seats for the
performance while minimizing interaction with side walls
(see figure 10).
Figure 10. The MartinLogan Theater delivers a 30 degree wave launch
dispersion pattern distributed horizontally.
Controlled Vertical Dispersion
As you can see below (See figure 11), your Theater speaker projects a controlled dispersion pattern. This vertical
dispersion profile minimizes interactions with the floor
and the ceiling. The controlled dispersion triple dipole
array extends the frequency range over which this happens.
Figure 11. The MartinLogan Theater vertical dispersion profile minimizes
interactions with the floor and ceiling.
Dispersion Interactions
11
Three Major Types of Dispersion
In the field of loudspeaker design, it is a known fact that as
the sound wave becomes progressively smaller than the
transducer producing it, the dispersion of that wave
becomes more and more narrow, or directional. This fact
occurs as long as the transducer is a flat surface. Large flat
panel speakers exhibit venetian blind effects due to this
phenomenon. This is why most manufacturers opt for
small drivers (i.e. tweeters and midrange) to approximate
what is known as a point source wave launch.
Figure 12–13. As can be seen here, point source
concepts invite a great deal of room interaction.
While delivering good frequency response to a
large listening audience, imaging is consequently
confused and blurred.
Figure 14–15. Even though they suffer from
“venetian blind” effect, angled multiple panel
speakers can deliver good imaging, but only
to specific spots in the listening area.
Figure 16–17. A controlled 30-degree cylindrical
wave-front, which is a MartinLogan exclusive,
offers optimal sound distribution with minimal
room interaction. The result is solid imaging with
a wide listening area.
ó12
Dispersion Interactions
Historically, most attempts to achieve smooth dispersion
from large flat panel transducers resulted in trade-offs.
After exhaustive testing of these different solution attempts,
we found an elegantly simple, yet very difficult to execute
solution. By curving the radiating surface, we create the
effect of a horizontal arc. This allows the engineers at
MartinLogan to control the high frequency dispersion
pattern of our transducers. That is why you see the gentle
curve on our products.
HOME THEATER
It had long been the practice of stereo buffs to connect their
television to the 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 ‘80’s two new home movie
formats became widely available to the public: VCR and
laser disc.
Surround Speakers.
We recommend that the surround speakers play down
to 80 Hz or below. The 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 a small inexpensive speaker. If you
choose to do so, be prepared to upgrade in the future as
discrete six channel digital encoding becomes available
and the demands on the surround speakers increase.
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.
Subwoofer.
With any good surround system you will need a high quality
subwoofer (the .1, in a 5.1 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.
Fortunately, "Dolby” and “DTS" encoded movies (which
include almost all movies) have the same surround sound
information encoded on home releases as the theater films.
All that is required to retrieve this information is a decoder
and additional speakers and amps to reproduce it.
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 only give you a brief outline of the
responsibilities and demands placed on each speaker.
Front Left and Front Right
If these speakers will also be the same two used for your
stereo playback then they should be of very high quality
and able to play loud (over 102 dB) and reproduce bass
below 80 Hz.
Center Channel.
This is the most important speaker in a video 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 designed by
the same manufacturer as the front speakers, and that it is
recommended for use as a center speaker. This is not the
place to cut corners.
Figure 18. Prodigy speakers as front channels, MartinLogan Theater as
the center channel, MartinLogan Scripts as side surround (effects) channels.
Home Theater
13
ELECTROSTATIC ADVANTAGES
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
loudspeakers 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: the stators,
the diaphragm and the 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 electrostatic transducer.
Notice the simplicity due to minimal parts usage.
14
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.
MARTINLOGAN EXCLUSIVES
Curvilinear Line Source (CLSTM)
Since the beginning of audio, achieving smooth dispersion
has been a problem for all loudspeaker designers. Large panel
transducers present even more of a challenge because the
larger the panel, the more directional the dispersion
pattern becomes.
Full 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 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 all MartinLogan products.
Transducer Integrity
All MartinLogan transducers begin with two pieces of highgrade, cold rolled steel. These steel pieces are then custom
perforated and insulated with a unique composite coating.
This proprietary coating insulates the stator to three times
its actual needed working voltage and gives the Theater a
wide margin of safe operation. In addition to the electrical
insulation properties, this coating also provides the Theater
with a durable, attractive finish that dampens the steel to
prevent ringing. These pieces are then sandwiched with
our exclusive vapor deposited diaphragm and spacers into
a curved geometry, and bonded together with aerospace
adhesives whose strength exceeds that of welding.
The result of these advanced technologies is a transducer
that is attractive, durable, highly rigid, well dampened,
and neutral.
Vapor Deposited Film
The diaphragm material used in all MartinLogan speakers
employs an extremely sophisticated conductive surface
that has been vapor deposited on the polymer surface at
an atomic level. A proprietary compound is vaporized then
electrostatically driven into the surface of the polymer film
in a vacuum chamber. This process allows an optically
transparent surface adding no mass to the diaphragm that
is extremely uniform in its surface resistivity characteristics.
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.
Controlled Dispersion Array
Most MartinLogan speakers are designed with vertically
oriented CLS transducers providing line sources from 2 to
over 5 feet. This provides excellent detail and coverage of
the listening area without the need for additional transducers.
The Theater's horizontally oriented eight inch vertical line
source requires an additional transducer to disperse high
frequency information.
In order to provide a high frequency dispersion pattern
that matches other MartinLogan speakers, we've added a
high frequency controlled dispersion array to the Theater.
The Theater Dispersion Array consists of three proprietary
high frequency drivers and specially engineered electronics
which maintain an expanded yet exact vertical dispersion
pattern throughout the high frequency spectrum.
The Theater's Dispersion Array also eliminates lobbing. This is
a non-uniform pattern which can result from closely spaced
wide-dispersion transducers firing a signal in the same
direction. This is addressed by configuring the center driver
to play only at frequencies above 8000Hz. Above 3000Hz,
the Dispersion Array also limits the output of both the upper
and lower drivers and above 10,000Hz, the central driver
begins to narrow it's dispersion.
This is how the Theater matches the dispersion and detail
characteristics of our other CLS electrostatic speaker systems
while limiting floor and ceiling reflections. The result is a
seamless soundstage and perfect clarity throughout your
home theater.
MartinLogan Exclusives
15
ELECTROSTATIC LOUDSPEAKER HISTORY
In the late 1800s, any loudspeaker was considered exotic.
Today, most of us take the wonders of sound reproduction
for granted.
The outcome would dictate the way that future generations
would refer to loudspeakers 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 Lodge
invented a cone loudspeaker, which he referred to
as a “bellowing telephone”, that was very similar to the
conventional cone loudspeaker drivers that we know
today. However, Lodge had no intention for his device to
reproduce music because in 1898 there was no way to
amplify an electrical signal! As a result, his speaker had
nothing to offer over the acoustical gramophones of the
period. It was not until 1906 that Dr. Lee DeForrest
invented the triode vacuum tube. Before this, an electrical
signal could not be amplified. The loudspeaker, as we know
it today, should have ensued then, but it did not. Amazingly,
it was almost twenty years before this would occur.
Bell Laboratory’s electrostat was something to behold.
This enormous bipolar speaker was as big as a door.
The diaphragm, which was beginning to rot, was made of a
pig intestine that was covered with fine gold leaf to conduct
the audio signal.
When Rice and Kellogg began playing the new electrically
cut records through the electrostat, they were shocked
and impressed. The electrostat performed splendidly.
They had never heard instrumental timbres reproduced
with such realism. This system sounded like real music
rather than the honking, squawking rendition of the
acoustic gramophone. Immediately, they knew they were
on to something big. The acoustic gramophone was destined
to become obsolete.
Due to Rice and Kellogg’s enthusiasm, they devoted a
In 1921, the electrically cut phonograph record became a
considerable amount of time researching the electrostatic
reality. This method of recording was far superior to the
design. However, they soon encountered the same difficulties
mechanically cut record and possessed almost 30 dB of
that even present designers face; planar
dynamic range. The acoustical gramospeakers require a very large surface
phone couldn’t begin to reproduce all
Rice and Kellogg had
area to reproduce the lower frequencies
of the information on this new disc. As
narrowed the field of
of the audio spectrum. Because the
a result, further developments in loudspeakers were needed to cope with “contestants” down to the management at Bell Labs considered
large speakers unacceptable, Rice and
this amazing new recording medium.
cone and the electrostat.
Kellogg’s work on electrostatics would
never be put to use for a commercial product. Reluctantly, they
By 1923, Bell Telephone Laboratories made the decision
advised the Bell management to go with the cone. For the
to develop a complete musical playback system consisting
next thirty years, the electrostatic design lay dormant.
of an electronic phonograph and a loudspeaker to take
advantage of the new recording medium. Bell Labs
assigned the project to two young engineers, C.W. Rice
During the Great Depression of the 1930s, consumer audio
and E.W. Kellogg.
almost died. The new electrically amplified loudspeaker
never gained acceptance, as most people continued to
Rice and Kellogg had a well equipped laboratory at their
use their old Victrola-style acoustic gramophones. Prior to
disposal. This lab possessed a vacuum tube amplifier with
the end of World War II, consumer audio saw little,
an unheard of 200 watts, a large selection of the new
if any, progress. However, during the late 1940s, audio
electrically cut phonograph, records and a variety of
experienced a great rebirth. Suddenly there was tremendous
loudspeaker prototypes that Bell Labs had been collecting
interest in audio products, and with that, a great demand
over the past decade. Among these were Lodge’s cone, a
for improved audio components. No sooner had the cone
speaker that used compressed air, a corona discharge (plasma)
become established than it was challenged by products
speaker, and an electrostatic speaker.
developed during this new rebirth.
After a short time, Rice and Kellogg had narrowed the field
of “contestants” down to the cone and the electrostat.
16
Electrostatic Loudspeaker History
In 1947, Arthur Janszen, a young Naval engineer, took part
to around 70 watts. As a result, many people continued
in a research project for the Navy. The Navy was interested
to use box speakers with cones.
in developing a better instrument for testing microphone
arrays. The test instrument needed an extremely accurate
In the early 1960s Arthur Janszen joined forces with the
speaker, but Janszen found that the cone speakers of the
KLH loudspeaker company, and together they introduced
period were too nonlinear in phase and amplitude response
the KLH 9. Due to the large size of the KLH 9, it did not
to meet his criteria. Janszen believed that electrostats
have as many limitations as the Quad. The KLH 9 could
were inherently more linear than cones, so he built a model
play markedly louder and lower in frequency than the
using a thin plastic diaphragm treated with a conductive
Quad ESL. Thus a rivalry was born.
coating. This model confirmed Janszen’s
beliefs, for it exhibited remarkable phase
Janszen continued to develop electroThese developments allow
and amplitude linearity.
static designs. He was instrumental
the consumer to own the
in the design of the Koss Model One,
Janszen was so excited with the results
the Acoustech, and the Dennesen
highest performance loudthat he continued research on the
speakers. Roger West, the chief
electrostatic speaker on his own time. speaker products ever built. designer of the JansZen Corporation
He soon thought of insulating the stators to
became the president of Sound Lab.
prevent the destructive effects of arcing. By 1952, he had
When JansZen Corporation was sold, the RTR loudspeaker
an electrostatic tweeter element ready for commercial
company bought half of the production tooling. This tooling
production. This new tweeter soon created a sensation
was used to make the electrostatic panels for the Servostatic, a
among American audio hobbyists. Since Janszen’s tweeter
hybrid electrostatic system that was Infinity’s first speaker
element was limited to high frequency reproduction, it
product. Other companies soon followed; each with their
often found itself used in conjunction with woofers, most
own unique applications of the technology. These include
notably, woofers from Acoustic Research. These systems
Acoustat, Audiostatic, Beverage, Dayton Wright, Sound
were highly regarded by all audio enthusiasts.
Lab, and Stax, to name a few.
As good as these systems were, they would soon be
surpassed by another electrostatic speaker.
In 1955, Peter Walker published three articles on electrostatic
loudspeaker design in Wireless World, a British electronics
magazine. In these articles, Walker demonstrated the benefits
of the electrostatic loudspeaker. He explained that electrostatics
permit the use of diaphragms that are low in mass, large in
area, and uniformly driven over their surfaces by electrostatic
forces. Due to these characteristics, electrostats have the
inherent ability to produce a wide bandwidth, flat frequency
response with distortion products being no greater than the
electronics driving them.
By 1956, Walker backed up his articles by introducing a
consumer product, the now famous Quad ESL. This speaker
immediately set a standard of performance for the audio
industry due to its incredible accuracy. However, in actual
use, the Quad had a few problems. It could not be played
very loud, it had poor bass performance, it presented a
difficult load that some amplifiers did not like, its dispersion
was very directional, and its power handling was limited
Electrostatic speakers have progressed and prospered
because they actually do what Peter Walker claimed they
would. The limitations and problems experienced in the
past were not inherent to the electrostatic concept. They
were related to the applications of these concepts.
Today, these limitations have been addressed. Advancements
in materials due to the U.S. space program give designers
the ability to harness the superiority of the electrostatic
principle. Today’s electrostats use advanced insulation
techniques or provide protection circuitry. The poor dispersion
properties of early models have been addressed by using
delay lines, acoustical lenses, multiple panel arrays or, as in
our own products, by curving the diaphragm. Power handling
and sensitivity have also been increased.
These developments allow the consumer the opportunity to
own the highest performance loudspeaker products ever
built. It’s too bad Rice and Kellogg were never able
to see just how far the technology would be taken.
Electrostatic Loudspeaker History
17
FREQUENTLY ASKED QUESTIONS
How do I clean my speakers?
Just use a dust free cloth or a soft brush to remove the
dust from your speakers. We recommend a specialty cloth
(available through the XStatic shop at www.martinlogan.com)
that cleans your speakers better than anything else we
have ever tried. Do not spray any kind of cleaning
agent on or in close proximity to the electrostatic
element.
What is the advantage of ESL?
Since the polyester film 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 of an amplifier should I use?
We recommend an amplifier with 100 to 200 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: a stable amplifier
will be able to deliver twice its rated wattage into 4 Ohms
and should again double 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.
18
Frequently Asked Questions
Is there likely to be any interaction between my speakers
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. In the case of our center channel
speakers, they are fully shielded and can be placed directly
on or near your television.
Will my electric bill go ‘sky high’ by leaving my speakers
plugged in all the time?
No. A pair of MartinLogans will draw about 5 watts
maximum. There is some circuitry to turn off the static
charge when not in use; however, the 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, stick, 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 speakers?
We recommend that you not place any loudspeaker in
direct sunlight, as 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 once or twice a year. This will be most
effective if the speaker has been unplugged for six
hours or overnight. You need not worry about the vacuum
pressure damaging the "delicate" membrane. It is
extraordinarily durable.
A problem has recently developed with my MartinLogan
speakers. The center 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. The electrostatic charge on
the element has attracted some airborne dust or pollen.
First unplug the speakers for six hours or overnight.
This will allow the charge to dissipate. Now vacuum
the front of the panel with a very strong vacuum.
Don’t worry about damaging the membrane. You won’t.
This should take care of your problem
By the way, 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. An easy way to do that is with a
power strip that has a switch.
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 speaker. The solution is simple. They only require
occasional vacuuming with a strong vacuum hose. You
will have best results when the speakers have been
unplugged for six hours or overnight. We are confident
that they will serve you very well.
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
19
TROUBLESHOOTING
No Output
•Check that all your system components are powered on.
•Check your speaker wires and connections.
•Check all interconnecting cables.
Weak Output, Loss of Highs
•Check the power cord. Is it properly connected to the speaker?
•Is the Theater properly adjusted towards the listening position?
Read Installation (pages 6–7) for more information.
20
Troubleshooting
Popping and Ticking Sounds, Funny Noises
•These occasional noises are harmless and will not hurt your
audio system or your speakers. All electrostatic speakers
are guilty of making odd noises at one time or another.
•These noises may be caused by dirt and dust particles
collecting on the speaker or by high humidity.
•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.
GENERAL INFORMATION
Specifications
The Theater hybrid speaker system consists of a broad-range
single element electrostatic transducer integrated with a
quick-response woofer. This approach takes advantage of
the benefits that both technologies have to offer. Dispersion
is a controlled 30 degrees. This was achieved by curving
the electrostatic transducer element itself, an elegantly
simple solution.
System Frequency Response
70–22,000 Hz ± 3 dB
Dispersion
30 degrees
Sensitivity
90 dB/2.83 volts/meter
Impedance
Nominal: 4 ohms, Minimum: 3.1 ohms @ 140 Hz
Crossover Frequencies
300, 3000 Hz
Woofer Type
Two 6.5” (16.5cm) magnetically shielded. Non-resonance
asymmetrical chamber format.
CLS Mid-Range
Patented CLS (curvilinear line source) electrostatic transducer
TM
TM
High Frequency Drivers
Three 1” (2.7cm) soft dome, controlled dispersion array
Power Handling
250 watts rms
Weight (With Mount)
57 lbs. (26kg)
Size (Without Mount)
43 inches W × 11.5 inches D × 10.5 inches H
(109.2cm W × 29.2cm D × 26.7cm H)
Warranty and Registration
Your Theater 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 speakers,
and provide a copy of your dealer receipt, to MartinLogan
within 30 days of purchase.
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 Theater speaker you cannot be assured of having
received new units. If this is the case, please contact your
authorized MartinLogan dealer.
Service
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 born by
the owner of the MartinLogan product.
3. If, after owning your speakers for six months, you
relocate to a country other than the one in which
you purchased your speakers, your warranty may be
transferable. Contact MartinLogan for details.
Size (With Mount)
43 inches W × 11.5 inches D × 13 inches H
(109.2cm W × 29.2cm D × 33cm H)
General Information
21
GLOSSARY
OF
AUDIO TERMS
AC. Abbreviation for alternating current.
DC. Abbreviation for direct current.
Active crossover. Uses active devices (transistors, ICs, 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.
Arc. The visible sparks generated by an electrical discharge.
Bass. The lowest frequencies of sound.
Bi-Amplification. Uses an electronic crossover, or line-level
passive crossover, and separate power amplifiers for the
high and low frequency loudspeaker drivers.
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.
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.
22
Glossary of Audio Terms
Diaphragm. A thin flexible membrane or cone that vibrates
in response to electrical signals to produce sound waves.
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.
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 (dB/w/m).
ESL. 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.
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.
Resistor. A device that is used in a circuit primarily to
provide resistance.
Inductor. A device designed primarily to introduce inductance
into an electrical circuit. Sometimes called a choke or coil.
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.
Linearity. The extent to which any signal handling process
is accomplished without amplitude distortion.
Sensitivity. The volume of sound delivered for a given
electrical input.
Midrange. The middle frequencies where the ear is the
most sensitive.
Stator. The fixed part forming the reference for the moving
diaphragm in a planar speaker.
Passive crossover. Uses no active components (transistors,
ICs, 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.
THD. The abbreviation for total harmonic distortion.
(See Distortion.)
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.
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.
Pink noise. A random noise used in measurements, as it has
the same amount of energy in each octave.
Transient. Applies to that which lasts or stays but a short
time. A change from one steady-state condition to another.
Polarity. The condition of being positive or negative with
respect to some reference point or object.
Tweeter. A small drive unit designed to produce only
high frequencies.
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.
Wavelength. The distance measured in the direction of
progression of a wave, from any given point characterized
by the same phase.
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.
TIM. The abbreviation for transient intermodulation distortion.
(See Distortion.)
White noise. A random noise used in measurements, as it
has the same amount of energy at each frequency.
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
23
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MA R T I N LOGA N
2101 Delaware Street, Lawrence, Kansas 66046, USA
tel 785.749.0133
fax 785.749.5320
©2000 MartinLogan, All rights reserved
www.martinlogan.com
Rev. #071300
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