TM
TM
F R E S C O
u s e r ’ s
m a n u a l
®
M A R T I N L O G A N
the loudspeaker technology company
INSTALLATION IN BRIEF
We know you are eager to hear your new Fresco loud-
speaker, 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 pos-
sible performance from this most exacting transducer.
Step 1: Unpacking
Remove your new Fresco speaker from the packing.
Step 2: Placement
Place the Fresco near the desired location. Please see the
‘Mounting the Fresco On a Wall or Ceiling’ section (page
5–12) for more placement details.
If you should experience any difficulties in the setup or
operation of your Fresco speaker, please refer to the
Operation or Mounting sections of this manual.
Step 3: 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 and ease of installation.
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.
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 Fresco. Take great care
to assign the same color to the (+) terminal on both the
speaker and the amplifier. Please see the ‘Operation’ sec-
tion (page 4) for more details.
WARNING!
•Refer servicing to a qualified technician.
•To prevent fire or shock hazard, do not
expose this module to moisture.
•Turn amplifier off should any abnormal
conditions occur.
Step 4: Listen and Enjoy
•Do not drive speaker beyond its rated power.
Now, you may turn on your system and enjoy!
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 mag-
nitude to constitute a risk of electric shock.
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
OPERATION
Signal Connection
On Wall/Off Wall Switch
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.
Fresco features a unique 'on-wall/off-wall' switch that tailors
Fresco's acoustic equalization to either installation option.
Simply set this switch to On Wall if the Fresco is mounted to
a wall or ceiling. Set the switch to Off Wall if the Fresco is more
than four inches from a wall (see figure 1).
Break-In
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 high-
est quality.
When you first begin to play your Fresco 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
woofers require 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 ATF transducer) are equal.
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 Fresco (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 Fresco. Take great care to assign the
same color to the (+) terminal on both the speaker and
the amplifier.
WARNING! Turn your amplifier off before mak-
ing or breaking any signal connections!
Figure 1. Single wire connection. One channel shown.
4
Operation
MOUNTING THE FRESCO ON A WALL OR CEILING
Figure 2. The parts of the Fresco bracket assembly.
NOTE: MartinLogan recommends using 5 wall anchors to
secure each Fresco to a wall. During the installation, if any
of the screw/wall anchor positions are over a stud, it is
recommended to screw directly into the stud.
Figure 3. Vertical Installation. Rotation direction for various installtion locations.
NOTE: To assure that your Fresco is safely wall mounted,
these instructions must be carefully followed. Study them
thoroughly before installing your Fresco's.
NOTE: The following instructions assume the mounting
surface is of standard wood frame and standard sheet rock
construction. If you wish to mount the Fresco to another
type of material, you should consult a bonded contractor.
WARNING! Installing the Fresco on a wall requires
only 1 person, but an assistant will be helpful.
The bracket assembly shipped with the Fresco
loudspeaker is designed for use only with the
Fresco. Use with other appliances may result in
instability causing possible injury. To prevent injury,
this apparatus must be securely attached to the
wall in accordance with the installation instructions.
Which Way Should It Rotate?
Figure 4. Horizontal Installation. Rotation direction for various installation locations.
The bracket assembly supplied with the Fresco allows the
speaker to mount flat against a wall and pivot up to 90°.
Depending on the installation locations, the Fresco on-wall
bracket will need to be modified to allow either right/up or
left/down rotation (see figure 3 and 4). The configuration of
Fresco’s bracket assembly is identical for right and up
rotation and is identical for left and down rotation.
Mounting the Fresco On A Wall or Ceiling
5
INSTALLATION
Preparing For Vertical Installation
NOTE: Fresco’s bracket assembly consists of two main
parts: the wall bracket (attaches to the wall) and the cabinet
bracket (attaches to the Fresco). When correctly configured
the wall and cabinet brackets should each have one pin
installed—the wall bracket with an upward pointing pin in
the upper hinge, and the cabinet bracket with a downward
pointing pin in the lower hinge (see figures 5 and 6).
Vertical
(Right Rotation)
Horizontal
(Up Rotation)
NOTE: When correctly installed in a vertical orientation, the
Fresco’s cabinet bracket (installed on the cabinet) should
slide down, onto the wall bracket (installed on the wall).
Each Fresco should be installed so that it can rotate to
point towards your listening position (see figure 3). Hold
each Fresco near it's desired location and try pivoting it to
assure that each speaker is correctly configured.
Preparing for Horizontal Installation
NOTE: Fresco’s bracket assembly consists of two main
parts: the wall bracket (attaches to the wall) and the cabinet
bracket (attaches to the Fresco). When correctly configured
each bracket should have one pin installed—the wall
bracket with a pin installed in the left hinge, pointing to
the left and the cabinet bracket with a pin installed in the
right hinge, pointing to the right (see figures 5 and 6).
Figure 5. Fresco’s bracket assembly configured for right/up rotation
Vertical
(Left Rotation)
NOTE: When the Fresco is correcty installed in a horizontal
orientation, gravity will pull on the speaker trying to rotate
down. The Fresco bracket assembly is designed in such a
way that the force of gravity will tighten the left cap nut and
prevent the speaker from rotating.
Horizontal
(Down Rotation)
Each Fresco should be installed so that it can rotate to
point towards your listening position (see figure 4). Hold
each Fresco near it's desired location and try pivoting it to
assure that each speaker is correctly configured.
Figure 6. Fresco’s bracket assembly configured for left/down rotation
6
Mounting the Fresco On A Wall or Ceiling
Changing the Direction of Rotation
Figure 7. Changing the direction of rotation—step 2.
Mounting the Fresco On A Wall or Ceiling
7
Installing the Bracket Assembly
Required hardware (included):
(6)M4 screws
Required tools (included):
2.5mm Allen tool
1 Prepare a flat surface with padding and sheets to pro-
tect the speaker as you work on it. Remove the Fresco's
grill cloth and carefully place the Fresco face down on
the work surface, using books or pieces of cardboard
to keep the speaker from rocking.
Figure 12. Installing the bracket assembly on the Fresco cabinet—step 2.
2 Using a 6mm Allen tool loosen the 2 cap nuts (see fig-
ure 12).
3 Rotate the wall bracket away from the cabinet bracket
(see figure 13).
4 Align the 6 holes in the Fresco's wall mounting bracket
with the holes on the back of the Fresco's cabinet.
Please note that the wall bracket should lie flat against
the Fresco cabinet with the hinges along the flat,
straight edge of the cabinet (see figure 14).
Figure 13. Installing the bracket assem
5 Using a 2.5MM Allen tool install the 6 screw that
attach the cabinet bracket and firmly tighten them (see
figure 15).
8
Mounting the Fresco On A Wall or Ceiling
Installing the Fresco
Required hardware (included):
(5) wall anchors
(5) 1" Phillips head wood screws
Required tools (included):
6mm Allen tool
Required tools (not included):
Level
Electric drill and 1/4" and 1/8" drill bits
Phillips screwdriver
1 Hold the Fresco at the desired location. Examine the mount-
ing location to assure that the wall is free of obstructions.
Test the direction of rotation to assure that the speaker
can rotate toward your listening position. If the speaker
rotates away from your listening position, please refer to
'Which Direction Should It Rotate?' (page 5) and ‘Changing
the Direction of Rotation’ (page 7).
2 NOTE: These instructions describe the position of the
wall bracket with the Fresco mounted flush against a
wall (not rotated on its bracket).
NOTE: The center point of the wall-bracket is not the
same as the center of the Fresco. These directions
describe the location of the center of the wall-bracket,
which you will need to know in order to mount the
speaker at your desired location.
Determine where the center point of the wall bracket
should be marked (see figures 16 and 17).
Will the Fresco remain flat against the wall? If so, it can
be installed flush against an object such as a plasma
screen (see figure18).
Will the Fresco be rotated to point towards the listening
position? If so you need to leave space between the
nearest object to allow clearance for the speaker to pivot
(see figure 18). At least 6.75” (17.2cm) of clearance will
allow the Fresco to pivot within its full range of motion.
Less space is needed if the Fresco does not need to fully
rotate. As recommended ablove, before drilling any
holes, hold the Fresco at its desired location and rotate
it into place to assure you have adequate clearance.
Figure 19. Attaching the Fresco to a wall or ceiling—step 3.
Figure 20. Attaching the Fresco to a wall or ceiling—step 4.
NOTE: Figures 19–24 illustrate the Fresco mounted in 4
different configurations.
4 Using a level, square the wall bracket and hold it flush
against the wall with the wall bracket's center hole over
the point you just marked. The cylindrical hinges on the
wall bracket should point away from the wall and the
flat plane of the wall bracket should be flush against the
wall. Mark 4 points inside of the wall bracket's arc shaped
cut outs located at either end of the wall bracket (see
figure 20).
3 Mark your wall with the center point for the wall bracket
(see figure 19).
10
Mounting the Fresco On A Wall or Ceiling
5 Set the wall bracket aside. Using a 1/8" bit, drill a pilot hole
at all five points marked in the previous steps.
6 Mount the wall bracket to the center wall anchor (or
pilot hole) using a 1" Phillips head screw driven through
the wall brackets center point. Do not fully tighten the
screw—the bracket must be leveled before installing the
remaining screws (see figure 22).
If a pilot hole hits a stud during this step, DO NOT WIDEN
that pilot hole or install a wall anchor at that location.
If a pilot hole does not hit a stud, use a 1/4" bit to widen
that pilot hole and using a Phillips screwdriver install a wall
anchor so that it is flush with the wall (see figure 21).
7 Using a level, square the bracket and drive the four
remaining 1" Phillips head screws into the wall anchors
(or pilot holes). Do not fully tighten the screws (see fig-
ure 22).
8 Using a level, make sure the bracket is level and tighten
all five screws (see figure 22).
Mounting the Fresco On A Wall or Ceiling
11
9 Place the Fresco onto the wall bracket and carefully slide
the Fresco into place (see figure 23).
10 Using a 6mm Allen tool, attach a washer and cap nut onto
each pin. Do not fully tighten the cap nuts (see figure 23).
11 Make the signal connections from the amplifier (see
‘Operation’, pages 4).
12 Rotate the Fresco to point at the listening position and
tighten the cap nuts (see figure 24).
13 Rotate the Fresco’s logo medallion, by removing the grill
cloth cover, gently pressing the medallion from behind
and turning it to the correct orientation (see figure 25).
12
Mounting the Fresco On A Wall or Ceiling
HOME THEATER
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.
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.
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.
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 infor-
mation 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 infor-
mation 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 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 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 26. Fresco loudspeakers as front, center and surround (effects)
channels. Grotto subwoofers as 0.1 (effects) channel.
Home Theater
13
ATF (ADVANCED THIN FILM)
ATF Operation
MartinLogan ATF diaphragms are constructed of extremely
low mass Dupont Kaladex® PEN (polyethylene naphthalate)
—a material chemically similar to the low-mass PET (poly-
ethelene terathylate) film used in MartinLogan's generation 2
electrostatic transducers, yet capable of handling the high
thermal requirements required for stable magnetic thin film
operation.
The MartinLogan ATF transducer consists of a micro-thin,
low-mass Kaladex diaphragm with an ultra-light, etched
conductive aluminum surface suspended between two high
field strength neodymium super magnet arrays (see figure 27).
When an electrical current (music signal) passes through the
etched aluminum on the diaphragm's surface it is simulta-
neously pulled towards one of the neodymium arrays and
pushed away from the opposing array. When the direction of
current is reversed the diaphragm is simultaneously pushed
and pulled in the opposite direction, thus producing sound.
High Field Strength
—Superb Control and Efficiency
With a field strength almost 2000% more powerful than
traditional systems, Neodymium iron boron (NIB) rare-earth
super magnets are one of the world's strongest commer-
cially available magnetic materials. This incredible field
strength proves ideal for maintaining perfect control over
the low-mass Kaladex diaphragm. Super-low distortion
levels, high-resolution, and crystal-clear transparency are just
a few of the benefits resulting from this superb combination
of low-mass diaphragm and high field strength.
Extremely Low-Mass Diaphragm
—Blazing Speed and Inner Detail
Low-mass diaphragms are crucial to a loudspeakers ability
to accurately reproduce sound. As the mass of a transducer's
diaphragm decreases, its ability to resolve detail increases.
With extremely low-mass characteristics, the ATF transducer
tracks the audio signal with almost perfect accuracy.
14
ATF (Advanced Thin Film)
Push-Pull Operation = Ideal Linearity
Linearity is another factor contributing to a loudspeaker's
ability to achieve ultimate clarity, detail and resolution. By
positioning neodymium magnet arrays in a push-pull con-
figuration, MartinLogan ATF transducer technology maintains
uniform diaphragm control, regardless of position as it
traverses the entire audio signal. The push-pull concept is
a major contributor to the linearity and sonic superiority of
ATF transducers.
Direct Full-Surface Drive
Provides Outstanding Clarity
Unlike traditional voice coil driven systems, ATF diaphragms
are directly and uniformly driven throughout their entire
surface. This full-surface drive system results in ultra-fast
transient response with no cone break up and the ability
to accurately reproduce sound with great delicacy, nuance
and clarity.
Figure 27. Cut away view of an ATF transducer. Note the simplicity due
to minimal parts usage.
ATF (Advanced Thin Film)
15
FREQUENTLY ASKED QUESTIONS AND TROUBLESHOOTING
Frequently Asked Questions
Troubleshooting
How do I clean my speakers?
Output
Just use a dust free cloth or a soft brush to remove the dust
from your speakers. We recommend a specialty cloth
(available at the Xtatic shop at www.martinlogan.com)
that cleans your speakers better than anything else we
have tried. Do not spray any kind of cleaning agent
on or in close proximity to the ATF element.
• Check that all your system components are turned on.
• Check your speaker wires and connections.
• Check all interconnecting cables.
What size amplifier should I use?
We recommend an amplifier with 100 watts per channel
for most applications. Probably less would be adequate
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 impor-
tant 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.
Is there likely to be any interaction between my speak-
ers and the television in my Audio/Video system?
The MartinLogan Fresco loudspeaker is fully shielded
and can go anywhere.
Will exposure to sunlight affect the life or perfor-
mance of my speakers?
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.
16
Frequently Asked Questions and Troubleshooting
GENERAL INFORMATION
Specifications
Warranty and Registration
System Frequency Response
75–20,000 Hz ± 3 dB
Your Fresco speaker is provided with an automatic Limited
90 Day Warranty coverage.
Sensitivity
90 dB/2.83 volts/meter
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.
Impedance
5 ohms
Crossover Frequency
500, 3200 Hz
For your convenience MartinLogan also offers online warranty
Components
Air core coils, metal film and low dissipation electrolytic
capacitors
MartinLogan may not honor warranty service claims unless
we have a completed Warranty Registration on file!
Woofer Type
If you did not receive a Certificate of Registration with your
new Fresco speaker, you cannot be assured of having
received new units. If this is the case, please contact your
authorized MartinLogan dealer.
Two 4” (10.2cm) magnetically shielded high rigidity alu-
minum cone with extended throw drive assembly,
non-resonance asymmetrical chamber format; bass reflex
ATF Mid-Range Driver
1.5" x 6" (3.8cm x 15.2cm) ATF Transducer
Service
ATF High Frequency Driver
1.5" x 2.25" (3.8cm x 5.7cm) ATF Transducer
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:
Power Handling
150 watts rms
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.
Weight
16 lbs. each (7.3 kg)
Size Without Stand
24” inches W × 4.9375” inches D × 8.25” inches H
(61cm W × 12.54cm D × 21.6cm H)
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 per-
formed 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.
Size With Stand
24” inches W × 5.6875” inches D × 8.25” inches H
(61cm W × 14.45cm D × 21.6cm H)
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.
General Information
17
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 mea-
sured 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.
ATF. The abbreviation for advanced thin film.
Bass. The lowest frequencies of sound.
Distortion. Usually referred to in terms of total harmonic
distortion (THD) which is the percentage of unwanted har-
monics of the drive signal present with the wanted signal.
Generally used to mean any unwanted change introduced
by the device under question.
Bi-Amplification. Uses an electronic crossover, or line-level
passive crossover, and separate power amplifiers for the
high and low frequency loudspeaker drivers.
Driver. See transducer.
Dynamic Range. The range between the quietest and the
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.
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).
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.
ESL. The abbreviation for electrostatic loudspeaker.
Headroom. The difference, in decibels, between the peak
and RMS levels in program material.
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.
Hybrid. A product created by the marriage of two different
technologies. Meant here as the combination of a dynam-
ic woofer with an electrostatic or ATF transducer.
Hz (Hertz). Unit of frequency equivalent to the number of
cycles per second.
CLS. The abbreviation for curvilinear linesource.
Imaging. To make a representation or imitation of the original
Crossover. An electrical circuit that divides a full bandwidth
signal into the desired frequency bands for the loudspeaker
components.
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.
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.
18
Glossary of Audio Terms
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 used in a circuit to provide resistance.
Resonance. The effect produced when the natural vibra-
tion frequency of a body is greatly amplified by reinforcing
vibrations at the same or nearly the same frequency from
another body.
Inductor. A device designed primarily to introduce inductance
into an electrical circuit. Sometimes called a choke or coil.
Sensitivity. The volume of sound delivered for a given
Linearity. The extent to which any signal handling process
electrical input.
is accomplished without amplitude distortion.
Stator. The fixed part forming the reference for the moving
Midrange. The middle frequencies where the ear is the most
diaphragm in a planar speaker.
sensitive.
THD. The abbreviation for total harmonic distortion. (See
NAC. The abbreviation for natural ambience compensation.
Distortion)
Passive crossover. Uses no active components (transis-
tors, 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.
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 elec-
trical 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.
Tweeter. A small drive unit designed to reproduce only
Pink noise. A random noise used in measurements, as it
high frequencies.
has the same amount of energy in each octave.
Wavelength. The distance measured in the direction of
progression of a wave, from any given point characterized
by the same phase.
Polarity. The condition of being positive or negative with
respect to some reference point or object.
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.
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.
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.
Glossary of Audio Terms
19
®
M A R T I N L O G A N
the loudspeaker technology company
2101 Delaware Street, Lawrence, Kansas 66046, USA tel 785.749.0133 fax 785.749.5320 www.martinlogan.com
Rev. #052803
©2003 MartinLogan. All rights reserved.
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