MartinLogan Sequel II User Manual

User's Manual

The Sequel II Speaker System

Important Contents

Your Sequel II
Limited 90 Day Warranty coverage.

You have the option, at no additional charge, to
receive Limited 3 Year Warranty coverage. To obtain
Limited 3 Year Warranty coverage you need only
complete and return the Certificate of Registration that
was included with your speakers to Martin-Logan,
within 30 days of purchase.

Martin-Logan may not honor warranty serviceMartin-Logan may not honor warranty service

Martin-Logan may not honor warranty service

Martin-Logan may not honor warranty serviceMartin-Logan may not honor warranty service
claims unless we have a completed Warrantyclaims unless we have a completed Warranty

claims unless we have a completed Warranty

claims unless we have a completed Warrantyclaims unless we have a completed Warranty
Registration card on file!Registration card on file!

Registration card on file!

Registration card on file!Registration card on file!

Should you be using your Martin-Logan product in a
country other than the one in which it was originally
purchased, we ask that you note the following:

1) The appointed Martin-Logan 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 Martin-Logan 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 Martin-Logan 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 Martin-Logan
product.

If you did not receive a Certificate of Registration with
your Sequel II
having received new units. If this is the case, plea

speakers are provided with an automatic

speakers you cannot be assured of

Introduction 3

Installation in Brief 4

The Electrostatic Concept 5

History 6

Martin-Logan Exclusives 8

Operation 10

Room Acoustics 14

Placement 18

Questions 21

Troubleshooting 22

Recommended Music 23

Glossary 24

Specifications 26

Notes 27

Page 2 Sequel II User's Manual

Introduction

Congratulations, you have invested in one of the world’s
premier loudspeaker systems!

The Martin-Logan Sequel II 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 Sequel II begins where the original Sequel was and
carries that level of performance several steps beyond. Bass
response now has better extension and improved definition,
high frequency response also has better extension and is
much more natural in character. Power handling and
system efficiency have been enhanced as well.

Like the original Sequel, all materials in your new Sequel II
speakers are of the highest quality to provide years of
enduring enjoyment and deepening respect. All trim
pieces are constructed from selected hardwoods. They are
then grain and color matched and finally hand finished.
The cabinetry is constructed from a special high-density
hardwood powderboard for structural integrity and is
finished with a durable and attractive suede paint.

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

tooled, high-grade steel, the panel is then coated with a
special polymer that is applied via a proprietary electro­static deposition process. This panel assembly houses a
membrane 0.0005 of an inch thick! Ruggedly constructed
and insulated, as much as 200 watts of continuous power
has driven the Sequel II’s energized diaphragm into
massive excursions with no deleterious effects.

We know you are anxious to listen to your new speakers. So,
to speed you along, we have provided an
BriefBrief

Brief

section ahead of the detailed descriptive information

BriefBrief
contained in this manual.

Please read and follow these instructions as you initially
connect your Sequel II
instructions are important and will prevent you from
experiencing any delay, frustration, or system damage
which might occur in a trial-and-error procedure.

The other sections of your
detail the operation of your Sequel II
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.

Happy Listening!

speakers into your system. These

User’s ManualUser’s Manual

User’s Manual will explain in

User’s ManualUser’s Manual

speakers and the

Installation inInstallation in

Installation in

Installation inInstallation in

Page 3Sequel II User's Manual

Installation in Brief

We know you are eager to hear your
new Sequel II loudspeakers, so this
section is provided to allow fast and
easy set up. Once you have them

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 best
possible performance from this most

exacting transducer.
If you should experience any difficul-

ties in the set-up or operation of your
Sequel II speakers, please refer to the

Room Acoustics, PlacementRoom Acoustics, Placement

Room Acoustics, Placement or

Room Acoustics, PlacementRoom Acoustics, Placement
OperationOperation

Operation section of this manual.

OperationOperation
Should you encounter a persistent

problem that cannot be resolved,
please contact your Authorized

Martin-Logan dealer. He will provide
you with the appropriate technical
analysis to alleviate the situation.

Step 1: UnpackingStep 1: Unpacking

Step 1: Unpacking

Step 1: UnpackingStep 1: Unpacking

Remove your new Sequel II

Step 2: PlacementStep 2: Placement

Step 2: Placement

Step 2: PlacementStep 2: Placement

Place each SequeI Il at least two feet from any wall and angle them slightly
toward your listening area. This is a good place to start. Please see the

ment ment

ment section of this manual for more details.

ment ment

Step 3: PStep 3: P

Step 3: P

Step 3: PStep 3: P

Martin-Logan speakers require AC power to energize their electrostatic cells.
Using the AC power cords provided, plug them in, making sure that you have
made a firm connection, first to the AC power receptacle on the rear panel of the
speaker and then to the wall outlet. Extension cords may be used, if necessary,
since the power requirement of the Sequel II is extremely small.

Step 4: Signal ConnectionStep 4: Signal Connection

Step 4: Signal Connection

Step 4: Signal ConnectionStep 4: Signal Connection

connections! The chassis is earth grounded and can present a

ower Connection (Aower Connection (A

ower Connection (A

ower Connection (Aower Connection (A

Turn your amplifier off before making or breaking any signal

short circuit to your amplifier if contact is made!

speakers from their packing.

C)C)

C)

C)C)

WARNING !WARNING !

WARNING !

WARNING !WARNING !

Place-Place-

Place-

Place-Place-

Use the best speaker cables you can! Higher quality cables, available from your
specialty dealer, are recommended and will give you superior performance! Spade
or banana connectors are suggested for optimum contact and ease of installation.

Attach your speaker cables to the
consistent when connecting speaker leads to the terminals on the back of the
Sequel II: take great care to assign the same color to the (+) terminal on both the
left and right channels. If bass is nonexistent and you cannot discern a tight,

coherent image, you may need to reverse the (+) and (-) leads on one side to bring
the system into proper polarity. For Bi-wiring/Passive Bi-amping instructions, turn to

OperationsOperations

the

Operations section of this manual for proper set-up of the Sequel II system.

OperationsOperations

Step 5: Listen and EnjoyStep 5: Listen and Enjoy

Step 5: Listen and Enjoy

Step 5: Listen and EnjoyStep 5: Listen and Enjoy

Now, you may turn on your system and enjoy!

Page 4 Sequel II User's Manual

Signal Input Signal Input

Signal Input section on the rear panel. Be

Signal Input Signal Input

The Electrostatic Concept

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, diaphrams 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 TransducerAn Electrostatic Transducer

An Electrostatic Transducer

An Electrostatic TransducerAn Electrostatic Transducer

An electrostatic transducer
consists of three pieces: the
stators, the diaphragm and the

Diaphragm

spacers (See Figure 1). The
diaphragm is what actually

Spacer

moves to excite the air and
create music. The stator's job is
to remain stationary, hence the
word stator, to provide a
reference point for the moving
diaphragm. The spacers

Figure 1Figure 1

Figure 1. Cut away view of an electrostatic transducer.

provide the diaphragm with a
fixed distance in which to move

Figure 1Figure 1

Notice the simplicity due to minimal parts usage.

between the stators.
As your amplifier sends music

signals to an electrostatic

An Electromagnetic TransducerAn Electromagnetic Transducer

An Electromagnetic Transducer

An Electromagnetic TransducerAn Electromagnetic Transducer

speaker, these signals are
changed into two high-voltage

Surround Cone

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

Basket Assembly

Magnet

Figure 2.Figure 2.

Figure 2. Cut away view of a typical moving coil driver.

Figure 2.Figure 2.

Notice the complexity due to the high number of parts.

as 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
require that the cone or dome
be perfectly rigid, damped
and massless. Unfortunately
these conditions are not

Stator

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

2). These pieces, when
combined with the high mass
of the cone or dome materi-

Dust Cap

Voice Coil Former

als used, make it an ex­tremely complex unit with
many weaknesses and
potential for failure. These
faults contribute to the high

Spider

distortion products found in
these drivers and is a
tremendous disadvantage
when you are trying to

Magnet Assembly

Magnetic GapVoice Coil

change motion as quickly
and as accurately as a
loudspeaker must (40,000
times per second!).

Page 5Sequel II User's Manual

History

In the late 1800’s, any loudspeaker was considered exotic.
Today, most of us take the wonders of sound reproduction
for granted.

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.

In 1921, the electrically cut phonograph record became a
reality. This method of recording was far superior to the
mechanically cut record and possessed almost 30 dB of
dynamic range. The acoustical gramophone couldn't
begin to reproduce all of the information on this new disc.
As a result, further developments in loudspeakers were
needed to cope with this amazing new recording medium.

By 1923, Bell Telephone Laboratories made the decision to
develop a complete musical playback system consisting
of an electronic phonograph and loudspeaker to take
advantage of the new recording medium. Bell Labs
assigned the project to two young engineers, C.W. Rice
and E.W. Kellogg.

Rice and Kellogg had a well equipped laboratory at their
disposal. This lab possessed a vacuum tube amplifier with
an unheard of 200 watts, a large selection of the new
electrically cut phonograph records and a variety of
loudspeaker prototypes that Bell Labs had been collecting
over the past decade. Among these were Lodge’s cone, a
speaker that used compressed air, a corona discharge
(plasma) speaker, and an electrostatic speaker.

After a short time, Rice and Kellogg had narrowed the field
of “contestants” down to the cone and the electrostat. The
outcome would dictate the way that future generations
would refer to loudspeakers as being either “conventional”,
or “exotic”.

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 the
membrane of a pigs 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 Kelloggs enthusiasm, they devoted a
considerable amount of time researching the electrostatic
design. However, they soon encountered the same difficul­ties that even present designers face; planar speakers
require a very large surface area to reproduce the lower
frequencies of the audio spectrum. Because the manage­ment at Bell Labs considered large speakers unaccept­able, Rice and Kelloggs work on electrostatics would never
be put to use for a commercial product. Reluctantly, they
advised the Bell management to go with the cone. For the
next thirty years the electrostatic design lay dormant.

During the Great Depression of the 1930's, consumer audio
almost died. The new electrically amplified loudspeaker
never gained acceptance, as most people continued to
use their old Victrola-style acoustic gramophones. Prior to
the end of World War II, consumer audio saw little, if any,
progress. However, during the late 1940's, audio experi­enced a great rebirth. Suddenly there was tremendous
interest in audio products and with that, a great demand
for improved audio components. No sooner had the cone
become established than it was challenged by products
developed during this new rebirth.

Page 6 Sequel II User's Manual

In 1947, Arthur Janszen, a young Naval engineer, took part
in a research project for the Navy. The Navy was interested
in developing a better instrument for testing microphone
arrays. The test instrument needed an extremely accurate
speaker, but Janszen found that the cone speakers of the
period were too nonlinear in phase and amplitude
response to meet his criteria. Janszen believed that
electrostats were inherently more linear than cones, so he
built a model using a thin plastic diaphragm treated with a
conductive coating. This model confirmed Janszen's
beliefs, for it exhibited remarkable phase and amplitude
linearity.

Janszen was so excited with the results that he continued
research on the electrostatic speaker on his own time. He
soon thought of insulating the stators to prevent the destruc­tive effects of arcing. By 1952 he had an electrostatic
tweeter element ready for commercial production. This new
tweeter soon created a sensation among American audio
hobbyists. Since Janszen's tweeter element was limited to
high frequency reproduction, it often found itself used in
conjunction with woofers, most notably, woofers from
Acoustic Research. These systems were highly regarded by
all audio enthusiasts.

load that some amplifiers did not like, its dispersion was
very directional, and its power handling was limited to
around 70 watts. As a result, many people continued to use
box speakers with cones.
In the early 1960's Arthur Janszen joined forces with the KLH
loudspeaker company and together they introduced the
KLH 9. Due to the large size of the KLH 9, it did not have as
many limitations as the Quad. The KLH 9 could play
markedly louder and lower in frequency than the Quad ESL.
Thus a rivalry was born.

Janszen continued to develop electrostatic designs. He
was instrumental in the design of the Koss Model One, the
Acoustech, and the Dennesen speakers. Roger West, the
chief designer of the JansZen Corporation became the
president of Sound Lab. When JansZen Corporation was
sold, the RTR loudspeaker company bought half of the
production tooling. This tooling was used to make the
electrostatic panels for the Servostatic, a hybrid electro­static system that was Infinity's first speaker product. Other
companies soon followed; each with their own unique
applications of the technology. These include Acoustat,
Audiostatic, Beverage, Dayton Wright, Sound Lab, and Stax
to name a few.

As good as these systems were, they would soon be
surpassed by another electrostatic speaker.

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 play very
loud, it had poor bass performance, it presented a difficult

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 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.

Page 7Sequel II User's Manual

Martin-Logan Exclusives

Full Range OperationFull Range Operation

Full Range Operation

Full Range OperationFull Range Operation

The most significant advantage of Martin-Logan's
exclusive transducer technology reveals itself when you
look at examples of other loudspeaker products on the

market today.
The Sequel II uses no crossover networks above 250 Hz

because they are not needed. The Sequel II consists of a
single, seamless electrostatic membrane reproducing all

frequencies above 250 Hz simultaneously. How is this
possible?

First we must understand that music is not composed of
separate high, mid and low

frequency pieces. In fact,
music is comprised of a single
complex waveform with all
frequencies interacting
simultaneously.

The electrostatic transducer of
the Sequel II essentially acts
as an exact opposite of the
microphones used to record

the original event. A micro­phone, which is a single
working element, transforms
acoustic energy into an
electrical signal that can be

amplified or preserved by
some type of storage media.
The Sequel II's electrostatic
transducer transforms electri­cal energy from your amplifier

into acoustical energy.
Due to the limitations of

electromagnetic drivers, no
single unit can reproduce the

full range of frequencies.

Figure 1. Figure 1.

Figure 1. Illustrates how a conventional speaker system

Figure 1. Figure 1.

must use a crossover network that has negative effects

on the musical performance unlike the Sequel II which

needs no crossover networks in the "critical zone".

Conventional Loudspeaker

TweeterTweeter

Tweeter

TweeterTweeter

MidrangeMidrange

Midrange

MidrangeMidrange

WooferWoofer

Woofer

WooferWoofer

Martin-Logan Sequel II Loudspeaker

Sequel IISequel II

Sequel II

Sequel IISequel II

ElectrostaticElectrostatic

Electrostatic

ElectrostaticElectrostatic

TransducerTransducer

Transducer

TransducerTransducer

WooferWoofer

Woofer

WooferWoofer

Instead, these drivers must be designed to operate
within narrow, fixed bandwidths of the frequency range
and then combined electrically so that the sum of the
parts equals the total signal. While nice in theory, we

must deal with real-world conditions.
In order to use multiple drivers, a crossover network is

enlisted to attempt a division of the complex musical
signal into the separate pieces (usually highs, mids,

and lows) that each specific driver was designed to
handle. Unfortunately, due to the phase relationships
that occur within all crossover networks and during the

acoustical recombination
process, nonlinearities and

severe degradation of the
music signal takes place in
the ear's most "critical zone"
(See Figure 1).

Critical ZoneCritical Zone

Critical Zone

Critical ZoneCritical Zone

250 - 20kHz250 - 20kHz

250 - 20kHz

250 - 20kHz250 - 20kHz

Critical ZoneCritical Zone

Critical Zone

Critical ZoneCritical Zone

250 - 20kHz250 - 20kHz

250 - 20kHz

250 - 20kHz250 - 20kHz

The Sequel II's electrostatic
transducer can single­handedly reproduce all
frequencies above 250 Hz
simultaneously. So you have,

in one transducer, the ability
to handle, in elegant simplic­ity, the critical frequencies
above 250 Hz.

The crossover phase disconti­nuities that are associated
with traditional tweeter,
midrange, and woofer systems
are eliminated. This results in a

dramatic improvement in
imaging and staging perform­ance due to the minutely
accurate phase relationship
of the full-range panel wave

launch.

Page 8 Sequel II User's Manual

Vapor Deposited FilmVapor Deposited Film

Vapor Deposited Film

Vapor Deposited FilmVapor Deposited Film

Curvilinear Line SourceCurvilinear Line Source

Curvilinear Line Source

Curvilinear Line SourceCurvilinear Line Source

The diaphragm material used in all Martin-Logan
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.

Transducer IntegrityTransducer Integrity

Transducer Integrity

Transducer IntegrityTransducer Integrity

All Martin-Logan transducers begin with two pieces of
high grade, cold rolled steel. These steel pieces are then
custom perforated and insulated with an exotic compos-

ite coating. This proprietary coating insulates the stator to
3 times its actual needed working voltage and gives the
Sequel II a wide margin of safe operation. In addition to
the electrical insulation properties, this coating also
provides the Sequel II 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.

Since the beginning of Audio, achieving smooth disper­sion has long 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, Martin-Logan 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 trans-

ducer, a controlled horizontal dispersion pattern could
be achieved, yet the purity of the almost massless
electrostatic diaphragm remained uncompromised. After
creating this technology, Martin-Logan developed the
production capability to bring this technology out of the

laboratory and into the market place.
You will find this proprietary Martin-Logan 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 Martin-Logan
products.

Page 9Sequel II User's Manual

Operation

AC Power ConnectionAC Power Connection

AC Power Connection

AC Power ConnectionAC Power Connection

Because your Martin-Logan Sequel II's use an internal power
supply to energize their electrostatic cells with high-voltage
DC, they must be connected to an AC power source. For this

reason they are provided with the proper IEC standard power
cords. These cords should be firmly inserted into the AC power
receptacles on the rear connection panel of the speakers,
then to any convenient AC wall outlet. Extension cords may be
used, if necessary, since the AC power requirement of the

speaker is extremely small (less than 2.5 watts). The Sequel II's
have been designed to remain on continuously and should
remain connected to a continuous AC power source. As
mentioned earlier, power consumption of the Sequel II's is very
small and the life expectancy of its components will not be

reduced by continuous operation.

The power cord should not be installed, removed, or

left detached from the speaker while the other end is

Your Sequel II speakers are 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 Sequel II speakers 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 a Sequel II speaker if
operation is attempted from an incorrect AC power source.

If your home is not equipped with three-prong wall outlets,
you may use “cheater” plugs to connect the speakers to AC
power. These may be obtained at your dealer or any
hardware department.

connected to an AC power source.

Signal ConnectionSignal Connection

Signal Connection

Signal ConnectionSignal Connection

Use the best speaker cables you can! The length and type
of speaker cable used in your system will have an audible
effect. Under no circumstance should a wire of gauge

higher (thinner) than #16 be used. In general, the longer
the length used, the greater the necessity of a lower gauge,
and the lower the gauge, the better the sound, with
diminishing returns setting in around #8 to #12.

A variety of speaker cables are now available whose
manufacturers claim better performance than with stan­dard heavy gauge wire. We have verified this in some
cases, and the improvements available are often more
noticeable than the differences between wires of different

gauge.
We would also recommend, if possible, that short runs of

speaker cable connect the power amplifier(s) and speak­ers 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. The effects of cables

may be masked if the equipment is not of the highest
quality.

Connections are done at the
rear electronics panel of the Sequel II. Use spade or

banana connectors for optimum contact and ease of
installation. Make certain that all your connections are tight
and positive.

Be consistent when connecting the speaker cables to the
Signal InputSignal Input

Signal Input terminals. Take care to assign the same

Signal InputSignal Input
color cable lead to the (+) terminal on both the left and
right channel speakers. If bass is nonexistent and you
cannot discern a tight, coherent image, you may need to
reverse the (+) and (-) leads on one speaker to bring the
system into proper polarity.

Signal InputSignal Input

Signal Input section on the

Signal InputSignal Input

Page 10 Sequel II User's Manual

Warning!Warning!

Warning!

Warning!Warning!

Turn your amplifier off before making or

breaking any signal connections! The

chassis is earth grounded and can

present a short circuit to your amplifier if

contact is made!

Standard ConnectionStandard Connection

Standard Connection

Standard ConnectionStandard Connection

Please take note of the jumper clips installed
under the 5-way binding posts. These clips
attach the high and low frequency sections
of the crossover together. Leaving these in
place, connect the (+) wire from your

amplifier to either Red binding post and the
(-) wire from your amplifier to either Black
binding post (See Figure 1).

Bi-Wire ConnectionBi-Wire Connection

Bi-Wire Connection

Bi-Wire ConnectionBi-Wire Connection

Figure 1Figure 1

Figure 1. Standard Connection. One channel shown.

Figure 1Figure 1

This method of connection replaces the
jumper clips installed under the 5-way
binding posts with individual runs of speaker
wire from your amplifier. This doubles the

signal carrying conductors from the audio
amplifier to the speaker, thus direct-coupling
each portion of the crossover to the amplifier.

To bi-wire you must f
binding posts and remove the jumperbinding posts and remove the jumper

binding posts and remove the jumper

binding posts and remove the jumperbinding posts and remove the jumper
clipsclips

clips. Connect one set of wires to the

clipsclips

HI-HI-

and

HI- binding posts of the Sequel II. Then

HI-HI-

connect a second set of wires to the

LO-LO-

and

LO- binding posts. Next, connect both

LO-LO-

sets of wires to the appropriate terminals on
your amplifier. Please take care to connect
both (+) wires to the (+) amplifier terminals
and both (-) wires to the (-) amplifier terminals.
This is known as a parallel connection (See

Figure 2).

irst loosen the 5-wayirst loosen the 5-way

irst loosen the 5-way

irst loosen the 5-wayirst loosen the 5-way

HI+HI+

HI+

HI+HI+

LO+LO+

LO+

LO+LO+

Figure 2.Figure 2.

Figure 2. Bi-Wire Connection. One channel shown.

Figure 2.Figure 2.

Page 11Sequel II User's Manual

Operation

Passive Bi-AmplificationPassive Bi-Amplification

Passive Bi-Amplification

Passive Bi-AmplificationPassive Bi-Amplification

For those of you that desire ultimate perfor­mance, the Sequel II may be passively bi­amplified using the existing internal passive

crossover elements.

WARNING!WARNING!

WARNING!

WARNING!WARNING!

Only after the jumper clips are removed

may you connect individual runs of speaker

cable from your amplifiers to the High-pass

and Low-pass Signal Input binding posts.

Damage will occur to your amplifiers if the

jumper clips are not removed!

This method takes the bi-wiring concept one
step further. Now you will have a dedicated
channel of amplification directly connected

to the high and low pass sections of the
Sequel II crossover. There are two different
methods for bi-amping with two stereo
amplifiers. The first and most common is
referred to as

is referred to as
you may use two stereo amplifiers or four mono amplifiers, or
two mono amplifiers and one stereo amplifier. Get the
idea? With either form of passive bi-amplification, your pre­amplifier must have dual outputs. If your pre-amplifier is not

so equipped, you must either purchase or construct a "Y"
adaptor.

Horizontal Bi-ampingHorizontal Bi-amping

Horizontal Bi-amping allows you to use two different

Horizontal Bi-ampingHorizontal Bi-amping
types, models or brands of amplifiers (i.e. tubes on top,
transistor on the bottom). However, we recommend that you
use two identical amplifiers (i.e. same brand and model). If
you must use two different amplifiers, it is essential that they

Horizontal Bi-ampingHorizontal Bi-amping

Horizontal Bi-amping. The second method

Horizontal Bi-ampingHorizontal Bi-amping

Vertical Bi-ampingVertical Bi-amping

Vertical Bi-amping. With either method

Vertical Bi-ampingVertical Bi-amping

Figure 3. Horizontal Passive Bi-amplification. One channel shown.

have the same gain or that one of the two have adjustable
gain so that you can match their gain characteristics. If the

amplifiers of choice do not have the same gain character­istics, then a sonic imbalance will occur.

Horizontal Bi-ampingHorizontal Bi-amping

With

Horizontal Bi-amping, one amplifier drives the high

Horizontal Bi-ampingHorizontal Bi-amping
pass section while the second amplifier drives the low pass
section. To
loosen the 5-way binding posts and remove the jumper clips.
Connect the low frequency amplifier to the
binding posts of both speakers. Connect the high frequency
amplifier to the
left and right preamplifier outputs to the appropriate left and
right inputs of both amplifiers (See Figure 3).

Horizontally Bi-ampHorizontally Bi-amp

Horizontally Bi-amp your Sequel II's you must

Horizontally Bi-ampHorizontally Bi-amp

HI+HI+

HI+ and

HI+HI+

LO+LO+

LO+ and

LO+LO+

HI-HI-

HI- binding posts. Next connect the

HI-HI-

LO-LO-

LO-

LO-LO-

Page 12 Sequel II User's Manual

Figure 4. Vertical Passive Bi-amplification. One channel shown.

Bass Control SwitchBass Control Switch

Bass Control Switch

Bass Control SwitchBass Control Switch

On the rear panel of the Sequel II electronics
module, below the
position

you to select the type of low frequency
response you desire.

The
setting for most rooms. However, if you feel

that the bass in your system is too light
relative to the mid and high frequencies,
simply select the
position will increase the output of the woofer
by 2dB.

Some experimentation with these two switch
settings will allow you to find the optimal
tonal balance for your specific taste, room
and equipment. Below is a graph showing

how the +2dB switch setting affects the
frequency response of the Sequel II.

Bass Control Bass Control

Bass Control switch that allows

Bass Control Bass Control

0 dB0 dB

0 dB position is considered the normal

0 dB0 dB

Signal InputSignal Input

Signal Input, is a two

Signal InputSignal Input

+2dB+2dB

+2dB position. This switch

+2dB+2dB

The very nature of
amplifiers be identical. With

the stereo amplifiers is dedicated to one speaker. For
instance, the left channel of each amplifier drives the low
pass section while the right channel drives the high pass
section. To

loosen the 5-way binding posts and remove the jumper
clips from both speakers. Starting with one speaker,
connect the left channel to the
and the right channel to the
Repeat the same procedure for the other speaker. Connect

the left preamplifier outputs to both inputs of the left
channel amplifier and the right preamplifier outputs to both
inputs of the right channel speaker (See Figure 4).

Vertically Bi-ampVertically Bi-amp

Vertically Bi-amp your Sequel II's you must

Vertically Bi-ampVertically Bi-amp

Vertical Bi-amping Vertical Bi-amping

Vertical Bi-amping dictates that both

Vertical Bi-amping Vertical Bi-amping

Vertical Bi-ampingVertical Bi-amping

Vertical Bi-amping, each of

Vertical Bi-ampingVertical Bi-amping

LO+LO+

LO+ and

LO+LO+

HI+HI+

HI+ and

HI+HI+

LO-LO-

LO- binding posts

LO-LO-

HI-HI-

HI- binding posts.

HI-HI-

+2dB

20Hz

50Hz 80Hz 160Hz 250Hz

Effects of the Bass Control switch

Page 13Sequel II User's Manual

Room Acoustics

YY

our Rour R

Y

our R

YY

our Rour R

oomoom

oom

oomoom

This is one of those areas that requires both a little
background to understand and some time and experi­mentation to attain the best performance from your
system.

Your room is actually a component and an important
part of your system. This component is a very large
variable and can dramatically add to, or subtract from,
a great musical experience.

All sound is composed of waves. Each note has its own
wave size, with the lower bass notes literally encompass­ing from 10' to as much as 40'! Your room participates in

TT

erminologyerminology

T

erminology

TT

erminologyerminology

Standing WavesStanding Waves

Standing Waves. The parallel walls in your room will

Standing WavesStanding Waves

reinforce certain notes to the point that they will
sound louder than the rest of the audio spectrum
and cause “one note bass”, “boomy bass” or “tubby
bass”. For instance, 100Hz represents a 10' wave­length. Your room will reinforce that specific
frequency if one of the dominant dimensions is 10'.
Large objects in the room such as cabinetry or
furniture can help to minimize this potential problem.
Some serious “audiophiles” will literally build a
special room with no parallel walls just to get away
from this phenomenon.

Reflective Surfaces (near-field reflections)Reflective Surfaces (near-field reflections)

Reflective Surfaces (near-field reflections). The

Reflective Surfaces (near-field reflections)Reflective Surfaces (near-field reflections)

hard surfaces of your room, particularly if close to
your speaker system, will reflect those waves back
into the room over and over again, confusing the
clarity and imaging of your system. The smaller
sound waves are mostly affected here and occur in
the mid and high frequencies. This is where voice
and frequencies as high as the cymbals can occur.

this wave experience like a 3 dimensional pool with
waves reflecting and becoming enhanced depending
on the size of the room and the types of surfaces in the
room.

Remember, your audio system can literally generate all
of the information required to recreate a musical event in
time, space, and tonal balance. The purpose of your
room, ideally, is to not contribute to that information.
However, every room does contribute to the sound and
the better speaker manufacturers have designed their
systems to accommodate this phenomenon.

Resonant Surfaces and ObjectsResonant Surfaces and Objects

Resonant Surfaces and Objects. All of the surfaces

Resonant Surfaces and ObjectsResonant Surfaces and Objects

and objects in your room are subject to the frequen­cies generated by your system. Much like an
instrument, they will vibrate and “carry on” in
syncopation with the music and contribute in a
negative way to the music. Ringing, boominess, and
even brightness can occur simply because they are
“singing along” with your music.

Resonant CavitiesResonant Cavities

Resonant Cavities. Small alcoves or closet type areas

Resonant CavitiesResonant Cavities

in your room can be chambers that create their own
“standing waves” and can drum their own “one
note” sounds.

Clap your hands. Can you hear an instant echo respond
back? You have near-field reflections. Stomp your foot on
the floor. Can you hear a “boom”? You have standing
waves or large panel resonances such as a poorly
supported wall. Put your head in a small cavity area and
talk loudly. Can you hear a booming? You’ve just
experienced a cavity resonance.

Page 14 Sequel II User's Manual

Rules of ThumbRules of Thumb

Rules of Thumb

Rules of ThumbRules of Thumb

Hard vs. Soft SurfacesHard vs. Soft Surfaces

Hard vs. Soft Surfaces. If the front or back wall of your

Hard vs. Soft SurfacesHard vs. Soft Surfaces

listening room is soft, it may benefit you to have a
hard or reflective wall in opposition. As well, the
ceiling and floor should follow the same basic
guideline. However, the side walls should be roughly
the same in order to deliver a focused image.

This rule suggests that a little reflection is good. As a
matter of fact, some rooms can be so “over damped”
with carpeting, drapes and sound absorbers that the
music system can sound dull and lifeless. On the
other hand, rooms can be so hard that the system
can sound like a gymnasium with too much reflec­tion and brightness. The point is that balance is the
optimum environment.

Break-up ObjectsBreak-up Objects

Break-up Objects. Objects with complex shapes, such

Break-up ObjectsBreak-up Objects

as bookshelves, cabinetry, and multiple shaped
walls can help break up those sonic gremlins and
diffuse any dominant frequencies.

Solid CouplingSolid Coupling

Solid Coupling. Your loudspeaker system generates

Solid CouplingSolid Coupling

frequency vibrations or waves into the room. This is
how it creates sound. Those vibrations will vary from
20 per second to 20,000 per second. If your speaker
system is not securely planted on the floor or solid
surface, it can shake as it produces sound and,
consequently, the sound can be compromised. If
your speaker is sitting on the carpet and only foot
gliders are used, the bass can be ill defined and
even boomy. The use of spikes is recommended to
insure secured footing for your speakers.

Bipolar SpeakBipolar Speak

Bipolar Speak

Bipolar SpeakBipolar Speak

Martin-Logan electrostatic loudspeakers are known as
bipolar radiators. This means that they produce sound
from both their fronts and their backs. Consequently,
musical information is reflected by the wall behind them
and may arrive either in or out of step with the information
produced by the front of the speaker.

The low frequencies can either be enhanced or nulled
by the position from the front wall. Your Sequel II's have
been designed to be placed 2 to 3 feet from the front
wall (the wall in front of the listening position) to obtain
the best results, however your room may see things
differently. So, listening to the difference of the bass
response as a result of the changes in distance from the
front wall can allow you to get the best combination of
depth of bass and tonal balance.

ers and Yers and Y

ers and Y

ers and Yers and Y

our Rour R

our R

our Rour R

oomoom

oom

oomoom

Now that you know about
Resonant ObjectsResonant Objects

Resonant Objects, you can see how the mid-range

Resonant ObjectsResonant Objects
and high frequencies can be affected. The timing of the
first wave as it is first radiated to your ears and then the
reflected information as it arrives at your ears later in time,
can result in confusion of the precious timing information
that carries the clues to imaging and, consequently result
in blurred imaging and excessive brightness. Soft walls,
curtains, wall hangings, or sound dampeners (your
dealer can give you good information here) can be
effective if these negative conditions occur.

Reflective SurfacesReflective Surfaces

Reflective Surfaces and

Reflective SurfacesReflective Surfaces

Page 15Sequel II User's Manual

Room Acoustics and Dispersion Interactions

Controlled Horizontal DispersionControlled Horizontal Dispersion

Controlled Horizontal Dispersion

Controlled Horizontal DispersionControlled Horizontal Dispersion

Your Sequel II's launch a 30 degree dispersion pattern
when viewed from above. This horizontal dispersion field
gives a choice of good seats for the performance while
minimizing interactions with side walls (See Figure 1).

Make sure both speakers stand exactly at the same
vertical angle, otherwise the image can be skewed or
poorly defined. The wave launch of both speakers is
extremely accurate in both the time and spectral domain
and, consequently, small refined adjustments can result
in noticeable sonic improvements.

Controlled Vertical DispersionControlled Vertical Dispersion

Controlled Vertical Dispersion

Controlled Vertical DispersionControlled Vertical Dispersion

As you can see from the illustrations, your Sequel II
speakers project a controlled dispersion pattern. Each
Sequel II is a four foot line source beginning two feet
above floor level (See Figure 2). This vertical dispersion
profile minimizes interactions with the floor and the
ceiling.

Figure 1Figure 1

Figure 1. Martin-Logan Sequel II's deliver a 30 degree wave

Figure 1Figure 1
launch dispersion pattern distributed horizontally.

Page 16 Sequel II User's Manual

Figure 2Figure 2

Figure 2. Your Sequel II speaker system is a 4 foot line

Figure 2Figure 2
source when viewed vertically. Actual height above the floor

is from two to six feet.

Three Major TThree Major T

Three Major T

Three Major TThree Major T

ypes of Dispersionypes of Dispersion

ypes of Dispersion

ypes of Dispersionypes 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
to this phenomenon. This is why most manufacturers opt
for small drivers (i.e. tweeters and midrange) to approxi­mate what is known as a

venetian blindvenetian blind

venetian blind effects due

venetian blindvenetian blind

point sourcepoint source

point source wave launch.

point sourcepoint source

As can be seen, point source con­cepts invite a great deal of room

interaction. While delivering good
frequency response to a large lis-

tening audience, imaging is con­sequently confused and blurred.

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.

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 Martin-Logan to control the high frequency
dispersion pattern of our transducers. That is why you see
the gentle curve on our products.

A controlled 30-degree cylindri­cal wave-front, which is a
Logan exclusiveLogan exclusive

Logan exclusive, offers optimal

Logan exclusiveLogan exclusive
sound distribution with minimal

room interaction. The result is solid
imaging with a wide listening area.

Martin-Martin-

Martin-

Martin-Martin-

Page 17Sequel II User's Manual

Placement

Listening PListening P

Listening P

Listening PListening P

By now your speakers should be placed approximately 2
to 3 feet from the front wall (wall in front of the listening
position) and at least 1 to 2 feet from the side walls. Your

sitting distance should be further than the distance
between the speakers themselves. What you are trying to
attain is the impression of good center imaging and
stage width.

There is no exact distance between speakers and
listener, but there is a relationship. In long rooms, natu­rally, that relationship changes. The distance between
the speakers will be far less than the distance from you to
the speaker system. However, in a wide room you will still

find that if the distance from the listener to the speakers
becomes smaller than the distance between the speak­ers themselves, the image will no longer focus in the
center.

Now that you have positioned your speaker system,
spend some time listening. Wait to make any major
changes in your initial set-up for the next few days as the
speaker system itself will change subtly in its sound. Over
the first 20 hours of play the actual tonal quality will

change slightly with deeper bass and more spacious
highs resulting.

After a few days of listening you can begin to make
refinements and hear the differences of those refinements.

The WThe W

The W

The WThe W

Near-field reflections can also occur from your back wall
(the wall behind the listening position). If your listening

position is close to the back wall, these reflections can
cause problems and confuse the quality of imaging.
Actually it is better for the wall behind you to be soft than
to be bright. If you have a hard back wall and your
listening position is close to it, experiment with devices

that will soften and absorb information (i.e. wall hang­ings and possibly even sound absorbing panels).

all Behind the Listenerall Behind the Listener

all Behind the Listener

all Behind the Listenerall Behind the Listener

ositionosition

osition

ositionosition

The WThe W

The W

The WThe W

The front wall (the wall behind your speakers), should not
be extremely hard or soft. For instance, a pane of glass
will cause reflections, brightness, and confused imaging.

Curtains, drapery and objects such as bookshelving can
be placed along the wall to tame an extremely hard
surface. A standard sheet rock or textured wall is gener­ally an adequate surface if the rest of the room is not too
bright and hard.

Sometimes walls can be too soft. If the entire front wall
consists of only heavy drapery, your system can literally
sound too soft or dull. You may hear dull, muted music
with little ambience. Harder room surfaces will actually

help in this case.
The front surface should, optimally, be one long wall

without any doors or openings. If you have openings, the
reflection and bass characteristics from one channel to

the other can be different.

The Side WThe Side W

The Side W

The Side WThe Side W

The same requirements exist for side walls. Additionally, a
good rule of thumb is to have the side walls as far away

from the speaker sides as possible, minimizing near field
side wall reflections. Sometimes, if the system is bright or
the imaging is not to your liking, and the side walls are
very near, try putting curtains or softening material

directly to the edge of each speaker. An ideal side wall,
however, is no side wall at all.

all Behind the Speakall Behind the Speak

all Behind the Speak

all Behind the Speakall Behind the Speak

allsalls

alls

allsalls

ersers

ers

ersers

Page 18 Sequel II User's Manual

ExperimentationExperimentation

Experimentation

ExperimentationExperimentation

Toe-inToe-in

Toe-in. Now you can begin to experiment. First begin by

Toe-inToe-in

toeing your speakers in towards the listening area
and then toeing them straight into the room. You will

notice that the tonal balance changes ever so
slightly. You will also notice the imaging changing.
Generally it is found that the ideal listening position is
with the speakers

listening to the inner third of the curved transducer
section.

Experimenting with the toe-in will help in terms of tonal
balance. You will notice that as the speakers are

toed-out, the system becomes slightly brighter than
when toed-in. This design gives you the flexibility to
modify a soft or bright room.

Tilting the Speakers Backwards and Forwards.Tilting the Speakers Backwards and Forwards.

Tilting the Speakers Backwards and Forwards. As

Tilting the Speakers Backwards and Forwards.Tilting the Speakers Backwards and Forwards.

can be seen from the diagrams in the
tics tics

tics section of this manual, the vertical dispersion is

tics tics
directional above and below the stator panel itself. In
some instances, if you are sitting close to the floor,
slight forward tilting of the speakers can enhance
clarity and precision.

Imaging. Imaging.

Imaging. In their final location, your Sequel II's should

Imaging. Imaging.

have a stage width somewhat wider than the
speakers themselves. On well recorded music, the

instruments should extend beyond the edges of each
speaker to the left and to the right, yet a vocalist
should appear directly in the middle. The size of the
instruments
should be neither too large nor too small. Additionally,

you should find good clues as to stage depth. Make
sure, when listening, that the vertical alignment,
distance from the front wall, and toe in is exactly the
same from one speaker to the other. This will greatly
enhance the quality of your imaging.

Bass Response. Bass Response.

Bass Response. Your bass response should neither be

Bass Response. Bass Response.

one note nor should it be too heavy. It should extend
fairly deep to even the deepest organ passages, yet it
should be tight and well defined. Kick-drums should

be tight and percussive, string bass notes should be
uniform and consistent throughout the entirety of the
run without any booming or thudding.

slightly toed-inslightly toed-in

slightly toed-in so that you are

slightly toed-inslightly toed-in

Room Acous-Room Acous-

Room Acous-

Room Acous-Room Acous-

Tonal Balance.Tonal Balance.

Tonal Balance. Voices should be natural and full,

Tonal Balance.Tonal Balance.

cymbals should be detailed and articulate yet not
bright and piercing, pianos should have a nice
transient characteristic and deep tonal registers as

well. If you cannot attain these virtues, re-read the
section on
on how to get closer to those ideal virtues.

A FA F

inal Winal W

A F

inal W

A FA F

inal Winal W

Final Placement.Final Placement.

Final Placement.

Final Placement.Final Placement.
After obtaining good wall treatments and attaining
proper angle, begin to experiment with the distance from
the wall behind the speakers. Move your speaker slightly
forward into the room. What happened to the bass
response? What happened to the imaging? If the
imaging is more open and spacious and the bass
response tightened, that is a superior position. Move the
speakers back six inches from the initial set-up position.
Again, listen to the imaging and bass response. There
will be a position where you will have pin-point imaging
and good bass response. That position becomes the
point of the optimal placement from the front wall.

Now experiment with placing the speakers farther apart.
As the speakers are positioned farther apart, listen again,
not so much for bass response but for stage width and
good pin-point focusing.

Your ideal listening position and speaker position will be
determined by:

1) tightness and extension of bass response,1) tightness and extension of bass response,

1) tightness and extension of bass response,

1) tightness and extension of bass response,1) tightness and extension of bass response,

2) the width of the stage, and2) the width of the stage, and

2) the width of the stage, and

2) the width of the stage, and2) the width of the stage, and

3) the pin-point focusing of imaging3) the pin-point focusing of imaging

3) the pin-point focusing of imaging.

3) the pin-point focusing of imaging3) the pin-point focusing of imaging

Once you have found the best of all three of those
considerations, you will have your best speaker location.

Room AcousticsRoom Acoustics

Room Acoustics. This will give you clues

Room AcousticsRoom Acoustics

ordord

ord

ordord

Page 19Sequel II User's Manual

Placement

The XThe X

The X

The XThe X

A major cable company developed the following
procedure for speaker placement. As a final test of exact
placement, use these measurements for your speakers

placement, and see what can happen to the ultimate
enhancement of your system’s performance.

The procedure consists of two basic measurements:

1) distance from the front wall (wall in front of the

To determine distance from the front wall, measure the
height of your ceiling (inches) and multiply the figure by

.618 (i.e. ceiling height in inches X .618 = distance from
the front wall to the center of the curvilinear transducer).

2) distance from the side-walls to the center of the

To determine distance from the side-walls, measure the
width of your room (inches) and divide the figure by 18,
next multiply the quotient by 5 (i.e. (room width in inches/

18) X 5 = distance from the side-walls to the center of the
curvilinear transducer).

-tra “-tra “

-tra “

-tra “-tra “

listening position) to the center of the curvilinear
transducer.

curvilinear transducer.

TT

week”week”

T

week”

TT

week”week”

Solid FSolid F

Solid F

Solid FSolid F

After living and experimenting with your Sequel II's, you
will then want to use the spikes included in your owners

kit. The Sequel II will become more firmly planted on the
floor and, consequently, bass will tighten and imaging
will become more coherent and detailed. It is best not to
implement the spikes, however, until you are secure in the
positioning as the spikes can damage the floors if the

speaker is moved.

Enjoy YEnjoy Y

Enjoy Y

Enjoy YEnjoy Y

The Sequel II is a very refined speaker and, as such,
benefits from care in set-up. With these tips in mind, you

will find, over your months of listening, that small changes
can result in demonstrable differences. As you live with
your speakers, do not be afraid to experiment with their
positioning until you find the optimal relationship

between your room and your speaker system to give you
the best results. Your efforts will be rewarded.

You are now armed with the fundamentals of room
acoustics and the specific fundamentals of the Sequel II

loudspeaker. Happy listening!

ootingooting

ooting

ootingooting

ourselfourself

ourself

ourselfourself

These two formulas will determine optimum placement of
your speakers to minimize standing waves.

Page 20 Sequel II User's Manual

Questions

What size amplifier should I use with the SequelWhat size amplifier should I use with the Sequel

What size amplifier should I use with the Sequel

What size amplifier should I use with the SequelWhat size amplifier should I use with the Sequel
II's?II's?

II's?

II's?II's?

We recommend an amplifier with 100 to 200 watts per
channel for most applications. The Sequel II will perform
well with either a tube or transistor amplifier, and will
reveal the sonic character of either type.

Do I need an amplifier with high current capa-Do I need an amplifier with high current capa-

Do I need an amplifier with high current capa-

Do I need an amplifier with high current capa-Do I need an amplifier with high current capa­bility?bility?

bility?

bility?bility?

No. The Sequel II's impedance characteristics do not
require that a high current amplifier be used. However,
it is important that the amplifier be stable operating into
varying impedance loads.

Should I unplug my Sequel II's during a thun-Should I unplug my Sequel II's during a thun-

Should I unplug my Sequel II's during a thun-

Should I unplug my Sequel II's during a thun-Should I unplug my Sequel II's during a thun­derstorm?derstorm?

derstorm?

derstorm?derstorm?

Yes. Or before. It’s a good idea to disconnect all of your
audio/video components during stormy weather.

Is there likely to be any interaction between theIs there likely to be any interaction between the

Is there likely to be any interaction between the

Is there likely to be any interaction between theIs there likely to be any interaction between the
Sequel II's and the television in my Audio/VideoSequel II's and the television in my Audio/Video

Sequel II's and the television in my Audio/Video

Sequel II's and the television in my Audio/VideoSequel II's and the television in my Audio/Video
system?system?

system?

system?system?

Actually, there is less interaction between a television
and an electrostatic speaker than between a television
and a conventional system. The magnets in conventional
speakers do interact with televisions tubes. However, we
do recommend that you keep your speakers at least one
foot away from the television because of the dynamic
woofer they employ.

Will my electric bill go ‘sky high’ by leaving myWill my electric bill go ‘sky high’ by leaving my

Will my electric bill go ‘sky high’ by leaving my

Will my electric bill go ‘sky high’ by leaving myWill my electric bill go ‘sky high’ by leaving my
speakers plugged in all the time?speakers plugged in all the time?

speakers plugged in all the time?

speakers plugged in all the time?speakers plugged in all the time?

Could my children, pets, or myself be shockedCould my children, pets, or myself be shocked

Could my children, pets, or myself be shocked

Could my children, pets, or myself be shockedCould my children, pets, or myself be shocked
by the high-voltage present in the electrostaticby the high-voltage present in the electrostatic

by the high-voltage present in the electrostatic

by the high-voltage present in the electrostaticby the high-voltage present in the electrostatic
panel?panel?

panel?

panel?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.

If my child punctured the diaphragm with aIf my child punctured the diaphragm with a

If my child punctured the diaphragm with a

If my child punctured the diaphragm with aIf my child punctured the diaphragm with a
pencil, stick, or similar item, how extensivepencil, stick, or similar item, how extensive

pencil, stick, or similar item, how extensive

pencil, stick, or similar item, how extensivepencil, stick, or similar item, how extensive
would the damage to the speaker be?would the damage to the speaker be?

would the damage to the speaker be?

would the damage to the speaker be?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 per-Will exposure to sunlight affect the life or per-

Will exposure to sunlight affect the life or per-

Will exposure to sunlight affect the life or per-Will exposure to sunlight affect the life or per­formance of the Sequel II?formance of the Sequel II?

formance of the Sequel II?

formance of the Sequel II?formance of the Sequel II?

We recommend that you not place your Sequel II's in
direct sunlight as the ultraviolet (UV) rays from the sun can
cause deterioration of grill cloth, speaker cones, etc.
However, small exposures to UV will not cause a problem.

Will excessive smoke or dust cause any prob-Will excessive smoke or dust cause any prob-

Will excessive smoke or dust cause any prob-

Will excessive smoke or dust cause any prob-Will excessive smoke or dust cause any prob­lems?lems?

lems?

lems?lems?

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 they were originally packed in.

No. A pair of Sequel II's draw about 5 watts maximum.

Page 21Sequel II User's Manual

Troubleshooting

No OutputNo Output

No Output

No OutputNo Output

Check that all your system components are turned on.

Check your speaker wires and connections.

Check all interconnecting cables.

Weak Output, Loss of HighsWeak Output, Loss of Highs

Weak Output, Loss of Highs

Weak Output, Loss of HighsWeak Output, Loss of Highs

Check the power cord. Is it properly connected to the
speaker?

Exaggerated Highs, Brightness.Exaggerated Highs, Brightness.

Exaggerated Highs, Brightness.

Exaggerated Highs, Brightness.Exaggerated Highs, Brightness.

Check the toe-in of the speakers. Read
mentment

ment for more information.

mentment

Muddy BassMuddy Bass

Muddy Bass

Muddy BassMuddy Bass

Check placement. Try moving the speakers closer to the
front and side walls.

Room Place-Room Place-

Room Place-

Room Place-Room Place-

Poor ImagingPoor Imaging

Poor Imaging

Poor ImagingPoor Imaging

Check placement. Are both speakers the same dis­tance from the walls? Do they have the same amount of
toe-in? Try moving the speakers away from the back
and side walls.

Check the polarity of the speaker wires. Are they con­nected properly?

Popping and Ticking Sounds, Funny NoisesPopping and Ticking Sounds, Funny Noises

Popping and Ticking Sounds, Funny Noises

Popping and Ticking Sounds, Funny NoisesPopping and Ticking Sounds, Funny Noises

These occasional noises are harmless and will nut 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, by high humidity or by AC
line fluctuations that may occur in your area.

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.

Check the type of feet being used. Try attaching the
coupling spikes.

Lack of BassLack of Bass

Lack of Bass

Lack of BassLack of Bass

Check your speaker wires. Is the polarity correct?

Page 22 Sequel II User's Manual

DO NOT SPRAY ANY KIND OF CLEANING AGENTDO NOT SPRAY ANY KIND OF CLEANING AGENT

DO NOT SPRAY ANY KIND OF CLEANING AGENT

DO NOT SPRAY ANY KIND OF CLEANING AGENTDO NOT SPRAY ANY KIND OF CLEANING AGENT
ON OR IN CLOSE PROXIMITY TO THE ELECTRO-ON OR IN CLOSE PROXIMITY TO THE ELECTRO-

ON OR IN CLOSE PROXIMITY TO THE ELECTRO-

ON OR IN CLOSE PROXIMITY TO THE ELECTRO-ON OR IN CLOSE PROXIMITY TO THE ELECTRO­STATIC ELEMENT.STATIC ELEMENT.

STATIC ELEMENT.

STATIC ELEMENT.STATIC ELEMENT.

Recommended Music

Analog Discs:Analog Discs:

Analog Discs:

Analog Discs:Analog Discs:

Astounding Sound Show ........... Reference Recordings RR-7

Chet Atkins in Hollywood................................ RCA LSP-1993

Berlioz: Symphonie Fantastique .......... Chesky Records CR1

Big Band Jazz ........................................ Umbrella UMB-DD4

The Chicago Symphony Winds ................. Sheffield Lab 22

Judy Collins: Judith....................................... Elektra 6E-111

Phil Collins: Face Value ..................................Virgin V-2185

Dafos ...................................... Reference Recordings RR-12

Miles Davis: You're Under Arrest ...........Columbia FC 40023

Arturo Delmoni:

Songs My Mother Taught Me ............ North Star DS0004

Dire Straits: Dire Straits ........................ Warner Bros. BSK 3266

Dire Straits: Love Over Gold .................. Warner Bros. 23728-1

Fresh Aire II .............................. American Gramophone 359

Fresh Aire III ............................. American Gramophone 365

Gershwin: An American in Paris .......... Chesky Records RC8

Earl Klugh: Crazy for You ............................ Liberty LT 51113

Mahler: Symphony No. 1............................ Telarc DG10066

Joni Mitchell: For the Roses ......................... Asylum SD 5057

Moroder: Cat People............................Backstreet BSR-6107

The Moscow Sessions....................... Sheffield Lab TLP-1000

Ohio Players: Gold .............................. Mercury SRM-1-1122

Pink Floyd: Dark Side of the Moon ....... EMI Harvest SHVL-804

Rachmaninoff: Piano Concerto No. 2 . Chesky Records CR2

The Reiner Sound .......................................... RCA LSC-2183

Rickie Lee Jones: Rickie Lee Jones ..... Warner Bros. BSK 3296

Shalamar: The Look........................................Solar 9-60239

The Sheffield Track Record ........................ Sheffield Lab-20

Strauss: Til Eulenspiegel .......... Reference Recordings RR-16

Stanley Turrentine: Cherry .................. CTI Records CTI 6017

McCoy Tyner & Jackie McLean:

It's About Time ................................. Blue Note BT 85102

Dionne Warwick: Soulful............................. Scepter SPS-573

Compact Discs:Compact Discs:

Compact Discs:

Compact Discs:Compact Discs:

Pachelbel Canon:

The Acadamy of Ancient Music, L'Oiseau-Lyre 410 553-2
Count Basie & His Orchestra: 88 Basie Street , Pablo 3112-42
David Benoit:

Every Step of the Way ...............GRP Records GRD-9558

This Side Up .................................... En Pointe ENP 0001

Cantate Domino ................................... Proprius PRCD 7762

Copland:

Appalachian Spring, Rodeo, Fanfare Telarc CD-80078

Country .............................. Windham Hill Records WD-1039

Dafos ................................ Reference Recordings RR-12 CD

Dire Straits: Brothers in Arms..............Warner Bros. 9 25264-2

Dorian Sampler Vol. 1 ........................... Dorian DOR-90001

Freddie Hubbard: Ride Like the Wind .... En Pointe ENP 0002

Huey Lewis and the News: Sports ...........Chrysalis VK 41412

Bob James & Earl Klugh: One On One........... CBS CK 36241

Albert King: Live Wire................... Mobile Fidelity MFCD 838

Rob McConnell and the Boss Brass:

Present Perfect ...................................... MPS 823 543-2

Nojima Plays Liszt .............. Reference Recordings RR-25CD

Linda Ronstadt: Round Midnight ............. Asylum 9 60489-2

Round-Up ................................................. Telarc CD-80141

Sainte-Saens: Symphony No. 3 ................ Philips 412 619-2

Diane Schuur and the Count Basie Orchestra,

GRP Records GRD-9550

Paul Simon: Graceland ................... Warner Bros. 9 25447-2

Ein Straussfest ........................................... Telarc CD-80098

Tchaikovsky: Piano Concerto No. 1..Chesky Records CD-13

Tchaikovsky: Violin Concerto ...........Chesky Records CD-12

Vollenweider: Caverna Magica ................... CBS MK 37827

Steve Winwood: Back in the High Life ........Island 9 25548-2

Yellowjackets: Shades ................MCA Records MCAD-5752

Page 23Sequel II User's Manual

Glossary

ACAC

AC. Abbreviation for alternating

ACAC

current.

Active crossoverActive crossover

Active crossover. Uses active

Active crossoverActive crossover

devices (transistors, IC’s,
tubes) and some form of power
supply to operate.

AmplitudeAmplitude

Amplitude. The extreme range of a

AmplitudeAmplitude

signal. Usually measured from the
average to the extreme.

ArcArc

Arc. The visible sparks generated by

ArcArc

an electrical discharge.

BassBass

Bass. The lowest frequencies of

BassBass

sound.

Bi-AmplificationBi-Amplification

Bi-Amplification. Uses an electronic

Bi-AmplificationBi-Amplification

crossover or line-level passive
crossover and separate power
amplifiers for the high and low
frequency loudspeaker drivers.

CapacitanceCapacitance

Capacitance. That property of a

CapacitanceCapacitance

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.

CapacitorCapacitor

Capacitor. A device consisting of

CapacitorCapacitor

two or more conducting plates
separated from one another by
an insulating material and used
for storing an electrical charge.
Sometimes called a condenser.

ClippingClipping

Clipping. Distortion of a signal by its

ClippingClipping

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.

CrossoverCrossover

Crossover. An electrical circuit that

CrossoverCrossover

divides a full bandwidth signal
into the desired frequency bands
for the loudspeaker components.

dB (decibel)dB (decibel)

dB (decibel). A numerical expres-

dB (decibel)dB (decibel)

sion of the relative loudness of a
sound. The difference in decibels
between two sounds is ten times
the common logarithm of the ratio
of their power levels.

DCDC

DC. Abbreviation for direct current.

DCDC
DiffractionDiffraction

Diffraction. The breaking up of a

DiffractionDiffraction

sound wave caused by some
type of mechanical interference
such as a cabinet edge, grill
frame, or other similar object.

DiaphragmDiaphragm

Diaphragm. A thin flexible mem-

DiaphragmDiaphragm

brane or cone that vibrates in
response to electrical signals to
produce sound waves.

DistortionDistortion

Distortion. Usually referred to in terms of

DistortionDistortion

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.

DriverDriver

Driver. See transducer.

DriverDriver
Dynamic RangeDynamic Range

Dynamic Range. The range

Dynamic RangeDynamic Range

between the quietest and the
loudest sounds a device can
handle (often quoted in dB).

EfficiencyEfficiency

Efficiency. The acoustic power

EfficiencyEfficiency

delivered for a given electrical
input. Often expressed as
decibels/watt/meter (dB/w/m).

ESLESL

ESL. Abbreviation for electrostatic

ESLESL

loudspeaker.

HeadroomHeadroom

Headroom. The difference, in

HeadroomHeadroom

decibels, between the peak and
RMS levels in program material.

HybridHybrid

Hybrid. A product created by the

HybridHybrid

marriage of two different tech­nologies. Meant here as the
combination of a dynamic
woofer with an electrostatic
transducer.

Hz (Hertz)Hz (Hertz)

Hz (Hertz). Unit of frequency equiva-

Hz (Hertz)Hz (Hertz)

lent to the number of cycles per
second.

ImagingImaging

Imaging. To make a representation

ImagingImaging

or imitation of the original sonic
event.

ImpedanceImpedance

Impedance. The total opposition

ImpedanceImpedance

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.

Page 24 Sequel II User's Manual

InductanceInductance

Inductance. The property of an

InductanceInductance

electric 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.

InductorInductor

Inductor. A device designed

InductorInductor

primarily to introduce inductance
into an electric circuit. Sometimes
called a choke or coil.

LinearityLinearity

Linearity. The extent to which any

LinearityLinearity

signal handling process is
accomplished without amplitude
distortion.

MidrangeMidrange

Midrange. The middle frequencies

MidrangeMidrange

where the ear is the most sensi­tive.

Passive crossoverPassive crossover

Passive crossover. Uses no active

Passive crossoverPassive crossover

components (transistors, IC’s,
tubes) and needs no power
supply (AC, DC, battery) to
operate. The crossover in a
typical loudspeaker is of the
passive variety. Passive cross­overs consist of capacitors,
inductors and resistors.

PhasePhase

Phase. The amount by which one

PhasePhase

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.

Pink noisePink noise

Pink noise. A random noise used in

Pink noisePink noise

measurements, as it has the same
amount of energy in each
octave.

PolarityPolarity

Polarity. The condition of being

PolarityPolarity

positive or negative with respect
to some reference point or object.

RMSRMS

RMS. Abbreviation for root mean

RMSRMS

square. The effective value of a
given waveform is its RMS value.
Acoustic power is proportional to
the square of the RMS sound
pressure.

ResistanceResistance

Resistance. That property of a

ResistanceResistance

conductor by which it opposes
the flow of electric current,
resulting in the generation of heat
in the conducting material,
usually expressed in ohms.

ResistorResistor

Resistor. A device used in a circuit

ResistorResistor

primarily to provide resistance.

ResonanceResonance

Resonance. The effect produced

ResonanceResonance

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.

SensitivitySensitivity

Sensitivity. Volume of sound

SensitivitySensitivity

delivered for a given electrical
input.

StatorStator

Stator. The fixed part forming the

StatorStator

reference for the moving dia­phragm in a planar speaker.

TIMTIM

TIM. Abbreviation for transient

TIMTIM

intermodulation distortion. (See
Distortion.)

TransducerTransducer

Transducer. Any of various devices

TransducerTransducer

that transmit energy from one
system to another, sometimes one
that converts the energy in form.
Loudspeaker transducers convert
electrical energy into mechani­cal motion.

TransientTransient

Transient. Applies to that which lasts

TransientTransient

or stays but a short time. A
change from one steady-state
condition to another.

TweeterTweeter

Tweeter. A small drive unit designed

TweeterTweeter

to produce only high frequencies.

WavelengthWavelength

Wavelength. The distance mea-

WavelengthWavelength

sured in the direction of progres­sion of a wave, from any given
point characterized by the same
phase.

White noiseWhite noise

White noise. A random noise used in

White noiseWhite noise

measurements, as it has the same
amount of energy at each
frequency.

WooferWoofer

Woofer. A drive unit operating in the

WooferWoofer

bass frequencies only. Drive units
in two-way systems are not true
woofers but are more accurately
described as being mid/bass
drivers.

THDTHD

THD. Abbreviation for total harmonic

THDTHD

distortion. (See Distortion.)

Page 25Sequel II User's Manual

Sequel II Specifications

System Frequency ResponseSystem Frequency Response

The Sequel II 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

System Frequency ResponseSystem Frequency Response
28-24,000 Hz ± 2dB

Electrostatic Frequency Re-Electrostatic Frequency Re-

Electrostatic Frequency Re-

Electrostatic Frequency Re-Electrostatic Frequency Re­sponsesponse

sponse

sponsesponse
100-24,000 Hz ± 2dB

Woofer Frequency ResponseWoofer Frequency Response

Woofer Frequency Response

Woofer Frequency ResponseWoofer Frequency Response
28-2,000 Hz ± 2dB

Woofer SpeedWoofer Speed

Woofer Speed

Woofer SpeedWoofer Speed
@ 50 Hz: 6.3ms (capable of 160 Hz)
@ 100 Hz: 1.2ms (capable of 830 Hz)

Bass Control SwitchBass Control Switch

Bass Control Switch

Bass Control SwitchBass Control Switch
+2dB from 40 - 160 Hz

Crossover FrequencyCrossover Frequency

Crossover Frequency

Crossover FrequencyCrossover Frequency
250 Hz at 12dB per octave

DispersionDispersion

Dispersion

DispersionDispersion
Horizontal: 30 Degrees
Vertical: 4' Line Source

SensitivitySensitivity

Sensitivity

SensitivitySensitivity
89dB/2.83 volts/meter

Power HandlingPower Handling

Power Handling

Power HandlingPower Handling
200 watts per channel

Recommended Amplifier PowerRecommended Amplifier Power

Recommended Amplifier Power

Recommended Amplifier PowerRecommended Amplifier Power
80 - 200 watts per channel

ImpedanceImpedance

Impedance

ImpedanceImpedance
Nominal: 6 ohms; Minimum: 2 ohms

Phase AnglePhase Angle

Phase Angle

Phase AnglePhase Angle
Less than 45

WeightWeight

Weight

WeightWeight
110 lbs/each

SizeSize

Size

SizeSize
72"H x 14"W x 13"D

ComponentsComponents

Components

ComponentsComponents
Custom-wound audio transformers
polypropylene bypass caps,
100% OFC coils.

o

Page 26 Sequel II User's Manual

Notes

Page 27Sequel II User's Manual

$ 3.00$ 3.00

$ 3.00

$ 3.00$ 3.00

THE ELECTROSTATIC TECHNOLOGY

2001 delaware street

p.o. box 707

lawrence, kansas 66044

ph: 913.749.0133

© 1989

martin-logan ltd.martin-logan ltd.

martin-logan ltd. all rights reserved

martin-logan ltd.martin-logan ltd.