Meyer Sound MSL-6 User Manual

Operating Instructions

MSL-6

Self-Powered Loudspeaker System

Copyright © 1997 Meyer Sound Laboratories, Inc.

All rights reserved

Part # 05.053.026.01 Rev A

Contents

Introduction .......................................................... 3

AC Power .............................................................. 3

Audio Input ........................................................... 5

Amplification and Protection Circuitry ............... 6

Rigging .................................................................. 7

Measurement and System Integration ............... 8

Complete Systems ............................................ 8

Driver Troubleshooting................................... 10

Dimensions ...................................................... 12

Physical Construction ..................................... 12

Safety Summary.............................................. 13

Controls and Connectors ................................ 14

Symbols Used

These symbols indicate important safety or operating features in this booklet and on the chassis.

!

Dangerous voltages:
risk of electric shock

Pour indiquer les risques

résultant de tensions

dangereuses

Zu die gefahren von

gefährliche spanning

zeigen

Para indicar azares

provengo de peligroso

voltajes

Important operating

instructions

Pour indequer important

instructions

Zu wichtige betriebs-

anweisung und unter-

haltsanweisung zeigen

Para indicar importante

funcionar y mantenimiento

instrucciones

Frame or chassis

Masse, châssis

Rahmen oder chassis

Armadura o chassis Tierra proteccionista

Protective earth ground

Terre de protection

Die schutzerde

Declaration of Conformity

According to ISO/IEC Guide and EN 45014

Name: Meyer Sound Laboratories
Address: 2832 San Pablo Avenue

Berkeley, California 94702-2204, USA

conforms to the following Product Specifications:

Safety: EN 60065: 1994
EMC: EN 55022: 1987 - Class A

IEC 801-2: 1984 - 8 kV
IEC 801-3: 1984 - 3 V/m
IEC 801-4: 1984 - 0.5 kV Signal Lines,

The product herewith complies with the require­ments of the Low Voltage Directive 73/23/EEC and
the EMC Directive 89/336/EEC.

Office of Quality Manager

Berkeley, California USA

October 1, 1995

Made by Meyer Sound, Berkeley, CA, USA

European Office:

Meyer Sound Germany
GmbH
Carl Zeiss Strasse 13
56751 Polch, Germany

1.0 kV Power Lines

declares that the product:The Manufacturer:

Product Name: MSL-6
Product Options: All

Environmental Specifications for

Meyer Sound Electronics Products

Operating temperature:0° C to +45° C
Nonoperating temp: < –40° C or > +75° C
Humidity: to 95% at 35°C
Operating altitude: to 4600 m (15,000 ft)
Nonoperating altitude: to 6300 m (25,000 ft)

Shock: 30 g 11 msec half-sine

on each of 6 sides

Vibration: 10 – 55 Hz (0.010 m

peak-to-peak excursion)

LISTED

UU

LL

®®

3K59

COMMERCIAL

AUDIO SYSTEM

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CC

2

Introduction

AC Power

The MSL-6, Meyer Sound’s largest self-powered speaker ,
is ideally suited for large-scale vocal public address
applications as a stand-alone system, and for musical
sound reinforcement in combination with Meyer self­powered subwoofers and/or the DS-2P mid-bass speaker .
The MSL-6 features a 25° vertical coverage angle,
permitting long-throw arrays with up to three vertical
rows with minimal overlap between coverage areas.

The center and outer high frequency horns utilize
separate amplifier and control electronics to achieve a
30° horizontal coverage angle for a single MSL-6. Tight­packing two units together yields a 60° coverage angle.
Since the MSL-6 is intended for tight-packing only, array
design is simple and modular: each additional unit
increases the horizontal coverage by 30°. The maximum
horizontal array size is twelve units, resulting in a
circular array with 360° coverage.

The MSL-6 contains amplifier and control electronics
for two 12” low frequency cone drivers and three high
frequency horn drivers (2” throat, 4” diaphragm) in a
compact trapezoidal cabinet. Each 12” driver is inde­pendently amplified and contained in a horn-loaded
vented enclosure. This integrated design improves
performance, durability, and reliability, eliminates
amplifier racks, and simplifies setup and installation.

The MSL-6 can be equipped to operate with the Remote
Monitoring System (RMS™) network and software
application. RMS displays signal and power levels, driver
and cooling fan status, limiter activity, and amplifier
temperature for all speakers in the network on a W indows­based PC. Contact Meyer Sound for more information
about RMS.

When AC power is applied to the MSL-6, the Intelligent
AC™ supply automatically selects the correct operating
voltage, allowing the MSL-6 to be used internationally
without manually setting voltage switches. The Intelligent
AC supply performs the following protective functions
to compensate for hostile conditions on the AC mains:

• suppresses high voltage transients up to several
kilovolts

• filters common mode and deference mode radio
frequencies (EMI)

• sustains operation during low voltage periods

• provides soft-start power-up, which eliminates
high inrush current

The MSL-6 can withstand continuous voltages up to
275 V and allows any combination of voltage to GND
(i.e. Neutral-Hot-GND, Hot-Hot-GND). Continuous
voltages higher than 275 V may damage the unit.

The MSL-6 uses a NEMA L6-20P or IEC 309 male power
inlet and satisfies UL, CSA, and EC safety standards.

Voltage Requirements

The MSL-6 operates safely and without audio disconti­nuity if the AC voltage stays within either of two operating
windows: 85–134 V or 165–264 V, at 50 or 60 Hz. After
applying AC power, the proper operating voltage is
automatically selected, but the system is muted. During
the next three seconds, the primary fans turn on, the
main power supply slowly ramps on, the green Active
LED on the user panel illuminates, and the system is
enabled to pass audio signals.

TROUBLESHOOTING NOTE: If the Active LED does
not illuminate or the system does not respond to audio
input after ten seconds, remove AC power. Electronics
technicians with access to a test bench can contact
Meyer Sound to receive

Series MP-2 and MP-4 Field Verification Procedure

(part # 17.022.066.01). This service document contains
a series of tests to verify that the power supply and
amplifier are functioning properly. Other users should
contact Meyer Sound or an authorized service center.

The Meyer Sound Self-Powered

3

If the voltage decreases below the lower bound of either
operating range (brown-out), the supply uses stored
energy to continue functioning briefly . The unit turns off
if the voltage does not increase above the threshold
before the storage circuits are depleted. The time that the
MSL-6 continues to operate during brown-out depends
on how low the voltage drops and the audio source level
during this period.

If the voltage fluctuates within either operating range,
automatic tap selection stabilizes the internal operating
voltage. This tap selection is instantaneous and there are
no audible artifacts. If the voltage increases above the
upper bound of either range, the power supply turns off
rapidly, preventing damage to the unit.

If the MSL-6 shuts down due to either low or high
voltage, the power supply automatically turns on after
three seconds if the voltage has returned to either normal
operating range. If the MSL-6 does not turn back on after
ten seconds, remove AC power and r efer to the

SHOOTING NOTE

NOTE: We recommend that the supply be operated at
least a few volts away from either window’s upper and
lower bounds so that small AC voltage variations do not
cause the supply to cycle on and off.

above.

TROUBLE-

Use the table below as a guide to select cables and circuit
breakers with appropriate ratings for your operating
voltage.

sgnitaRtnerruC6-LSM

V511 V032 V001

SMRsuounitnoC.xaM

SMRtsruB.xaM

A41

A62

tsruBgniruDkaeP.xaM

A83

A7

SMR

A31

SMR

A81

KAEP

A61

SMR

SMR

KAEP

SMR

A03

SMR

A24

KAEP

The minimum electrical service amperage required by a
system of MSL-6s is the sum of their maximum
continuous RMS current. We recommend allowing an
additional 30% above the minimum amperage to prevent
peak voltage drops at the service entry.

TROUBLESHOOTING NOTE: In the unlikely case that
the circuit breakers trip (the white center buttons pop
out), do not reset the breakers! Contact Meyer Sound for
repair information.

Power Connector Wiring Conventions

Current Requirements

The MSL-6 presents a dynamic load to the AC mains
which causes the amount of current to fluctuate between
quiet and loud operating levels. Since different types of
cables and circuit breakers heat up at varying rates, it is
essential to understand the types of current ratings
and how they correspond to circuit breaker and cable
specifications.

The maximum continuous RMS current is the maximum
RMS current in a period of at least 10 seconds. It is used
to calculate the temperature increase in cables, which is
used to select cables that conform to electrical code
standards. It is also used to select the rating for slow­reacting thermal breakers.

The maximum burst RMS current is the maximum RMS
current in a period of approximately 1 second. It is used
to select the rating for most magnetic breakers.

The maximum instantaneous peak current during burst
is used to select the rating for fast-reacting magnetic
breakers and to calculate the peak voltage drop in long
AC cables according to the formula

Use the following AC cable wiring diagram to create
international or special-purpose power connectors:

blue =
neutral

yellow/green =
earth ground
(chassis)

AC cable color code

brown = hot

If the colors referred to in the diagram don't correspond to
the terminals in your plug, use the following guidelines:

• Connect the blue wire to the terminal marked
with an N or colored black.

• Connect the brown wire to the terminal marked
with an L or colored red.

• Connect the green and yellow wire to the terminal
marked with an E (or ) or colored green (or
green and yellow).

Vpk

= Ipk x Rtotal cable

drop

4

Safety Issues

Pay close attention to these important electrical and
safety issues.

Use a power cord adapter to drive the MSL-6
from a standard 3-prong outlet
(NEMA 5-15R;125 V max).

earth
ground

chassis
ground

The MSL-6 requires a grounded outlet. Always
use a grounding adapter when connecting to
ungrounded outlets.

Audio Input

The MSL-6 presents a 10 kΩ balanced input impedance to
a three-pin XLR connector wired with the following
convention:

Pin 1 — 220 kΩ to chassis and earth ground (ESD clamped)
Pin 2 — Signal
Pin 3 — Signal
Case — Earth (AC) ground and chassis

Pins 2 and 3 carry the input as a differential signal; their
polarity can be reversed with the input polarity switch
on the user panel. If the switch is in the up position,
pin 2 is hot relative to pin 3, resulting in a positive
pressure wave when a positive signal is applied to pin 2.
Use standard audio cables with XLR connectors for
balanced signal sources.

TROUBLESHOOTING NOTE: Shorting an input connector
pin to the case can form a ground loop and cause hum.
If other abnormal noises (hiss, popping) are produced
from the loudspeaker, disconnect the audio source from
the speaker. If the noise stops, then the problem is not
within the loudspeaker; check the audio input and AC
power.

Differential Inputs

Do not use a ground-lifting adapter or cut the AC
cable ground pin.

Keep all liquids away from the MSL-6 to avoid hazards
from electrical shock.

Do not operate the unit if the power cables are frayed or
broken.

Tie-wrap anchors on the amplifier chassis provide strain
relief for the power and signal cables. Insert the plastic
tie-wraps through the anchors and wrap them around
the cables.

A single sour ce can drive multiple MSL-6s with a paral­leled input loop, creating an unbuffered har dwired loop
connection. Make certain that the source device can
drive the total load impedance presented by the paral­leled input circuit. For example, since the input imped­ance of a single MSL-6 is 10 kΩ, cascading 20 units
produces a balanced input impedance of 500 Ω. If a 150 Ω
source is used, the 500 Ω load results in a 2.28 dB loss.

5

Amplification and Protection
Circuitry

The MSL-6 is powered by the Meyer MP-4, a four­channel 2480 W amplifier (620 W/ch) utilizing comple­mentary power MOSFET output stages (class AB/H).
The following sections discuss the MP-4’s limiting circuitry
and four-fan cooling system.

The TruPower™ Limiting System

Conventional limiters assume that the resistance of a
speaker remains constant and set the limiting threshold
by measuring voltage only. This method is inaccurate
because the speaker’s resistance changes in r esponse to
the frequency content of the source material and thermal
variations in the speaker’s voice coil and magnet. Con­ventional limiters begin limiting prematurely, which
under-utilizes system headroom and deprives the speaker
of its full dynamic range.

The T ruPower Limiting (TPL) system accounts for varying
speaker impedance by measuring current, in addition to
voltage, to compute the actual power dissipation in the
voice coil. TPL

The MSL-6 performs within its acoustical specifications
and operates at a normal temperature if the limit LEDs
are on for no longer than two seconds, and off for at least
one second. If either LED remains on for longer than
three seconds, that channel is hard limiting with the
following negative consequences:

• Increasing the input level will not increase the
volume.

• The system distorts due to clipping and nonlinear
driver operation.

• Unequal limiting between the low and high
channels alters the frequency response.

• The life-span of the drivers is reduced because
they are subjected to excessive heat.

The TPL LEDs can indicate an imbalance in a configuration
of speakers by functioning like a spectrum analyzer. If
the speakers in a subwoofer, mid-bass, or mid-hi sub­system begin to limit before reaching the required
operating level for the entire system, then that subsystem
needs to be supplemented with additional speakers.

NOTE: Although the TPL limiters exhibit smooth sonic
characteristics, we do not recommend using them for
intentional compression effects. Use an outboard
compressor/limiter to compress a mixed signal.

• improves performance before and during limiting
by allowing each driver to produce its maximum
SPL across its entire frequency range;

• protects the drivers by controlling the temperature
of the voice coil;

• eliminates long-term power compression when
the system is operated at high levels for extended
periods.

The true power is monitored for each of the four amplifier
channels, which are controlled by two limiters. The
outer two and center high frequency drivers are driven
by separate amplifier channels but are routed to one
limiter: the HI Limit LED on the user panel indicates
TPL activity for the horns. The two low frequency drivers
are driven by separate amplifier channels but are routed
to one limiter: the LO Limit LED indicates TPL activity
for the low drivers.

When any channel exceeds the safe continuous power
level, its limiter engages, affecting both channels equally.
For example, if the channel for the outer two horns
exceeds the safe power level, the high limiter engages,
limiting the center, as well as the outer two horns. The
high and low limiters function independently and do not
affect the signal when the LEDs are inactive.

VHF Limiting

At normal operating levels, the outer two horns receive
a high frequency boost (centered at 1 1 kHz) to blend with
the center horn to achieve smooth horizontal coverage.
At high operating levels, however, this boost can cause
distortion and premature TPL limiting.

To preserve headroom and maintain smooth high fre­quency response at high operating levels, the channel
for the outer two horns has a fast-acting VHF (very high
frequency) limiter that reduces the amplitude of fre­quencies around 11 kHz. Increased acoustical HF
harmonic content generated at high signal levels
compensates for the effects of the VHF limiter , r endering
its operation almost imperceptible. VHF limiting is
indicated by the VHF Limit LED on the user panel; the
same on/off cycle discussed for the TPL limiters applies
to the VHF limiter.

6

Fans and Cooling System

The MSL-6 uses a forced-air cooling system with four
fans to prevent the amplifiers from overheating. The fans
draw air in through ducts on the front of the cabinet,
over the heatsinks, and out the rear of the cabinet. Since
dust does not accumulate in the amplifier circuitry, its
life-span is increased significantly.

The front grill surface acts as an air filter for the cooling
system and should always be in place during operation.
Despite the filtering, extensive use or a dusty operating
environment can allow dust to accumulate along the
path of the airflow, preventing normal cooling. We
recommend periodically removing the grill and amplifier
module and using a vacuum cleaner to clear dust from
the grill, fans, and heatsinks. Make sure that the air ducts
are clear and that there is at least six inches clearance
for exhaust behind the cabinet.

amplifier

heatsinks

fans

air
intake

Rigging

A single MSL-6 weighs 510 lb (282 kg) and has twelve
pivoting lift rings (six on top, six on bottom), each with
a maximum working load capacity of 1500 lb (5:1
safety factor). The rigging hardware is depicted on page
12 in the

Rigging load ratings assume a straight tensile pull and
that the cabinet is in new condition. If these conditions
are not met, the load ratings can be reduced significantly.
Load ratings can also be reduced by age, wear, and
damage. It is important to inspect the rigging hardware
regularly and replace worn or damaged components
immediately.

The cabinet, exposed electronic circuitry, and drivers can
receive protective treatment that permits safe use in wet
conditions. Additionally, a rain hood can be fitted to
shield cables and electronics. Do not install a unit outdoors
without weather protection! Contact Meyer Sound for more
information.

NOTE: All Meyer Sound products must be used in
accordance with local, state, federal, and industry regu­lations. It is the owner’s and/or user’s responsibility to
evaluate the reliability of any rigging method for their
application. Rigging should be done only by experienced
professionals.

Dimensions

section.

Two variable-speed primary fans run continuously with
an inaudible operating noise of 22 dBA at 1 m at their
slowest speed. The primary fans begin increasing speed
when either of the two heatsinks reaches 42°C. The fans
reach full speed at 62°C and are barely audible near the
cabinet, even without an audio signal.

In the unusual event that the heatsink temperature
reaches 74°C, the secondary fans turn on and are clearly
audible. The secondary fans turn on in response to

• primary fan failure (check status immediately);

• high source levels for a prolonged period in hot
temperatures or direct sunlight;

• accumulation of dust along the cooling path;

• driver failure.

The secondary fans turn off when the temperature
decreases to 68°C.

TROUBLESHOOTING NOTE: In the highly unlikely event
that the secondary fans do not keep the temperature
below 85°C, the MSL-6 automatically shuts down until
AC power is removed and reapplied. If the MSL-6 shuts
down again after cooling and reapplying AC power,
contact Meyer Sound for repair information.

7

Measurement and System
Integration

Measurement and correction tools are required to
assemble a complete sound system, particularly when
the venue requires precise array design, delay systems,
or compensation for significant reverberation. We
recommend using the Meyer SIM® System II Sound
Analyzer and CP-10 Parametric Equalizer to

• assist the process of choosing and configuring
speakers;

• measure propagation delays between subsystems
to set the correct polarity and delay times;

• measure and equalize variations in frequency
response caused by the acoustical environment
and the placement and interaction of speakers.

Complete Systems

Meyer Speaker Types

The following Meyer speakers are mentioned in the
example applications.

MSL-4 Self-powered mid-hi speaker

DS-2P Self-powered mid-bass speaker

PSW-2 Self-powered subwoofer

650-P Self-powered subwoofer

The Meyer self-powered speakers listed above have a
loop connection to send the input signal to another
speaker. Full-range signals can be applied to all Meyer
self-powered subwoofers because they have built-in
active crossovers that filter mid-hi frequencies.

We recommend using the Meyer LD-1A Line Driver to
integrate different types of Meyer self-powered speakers
into a complete system. The LD-1A has two channels
equipped to control a main system and six auxiliary
channels for down-fill, front-fill, and delay systems.
The LD-1A maintains signal integrity for long cable
paths and provides the following useful functions:

• The Lo Cut switch activates a high-pass filter
(160 Hz, –12 dB/oct, Q = 0.8) that performs a
crossover function for the Mid-Hi output.

• The Array EQ switch activates a filter (6 dB cut
at 220 Hz, 0.6 octave bandwidth) to equalize
horizontal arrays of 3 to 5 MSL-4s.

• The DS-2 & Sub Crossover switch (channels 1 and
2 only) activates a crossover network optimized
for the DS-2P when used with the 650-P. With the
switch in, frequencies below 80 Hz are sent to the
Sub output (for the 650-P), and above 80 Hz to the
DS-2 output. When the 650-P is used without the
DS-2P, the switch should be out, which sends a
full-range signal to both the DS-2 and Sub outputs.

• The DS-2 φ and Sub φ switches (channels 1 and 2
only) toggle the polarity for the DS-2 and Sub
outputs.

• The Mid-Hi, DS-2, and Sub outputs (channels 1
and 2 only) each have their own gain control and
mute switch.

Flown MSL-6 and MSL-4;
650-P on the Floor

This example shows a lar ge concert system contr olled by
the LD-1A consisting of two rows of two MSL-6s (lower
row at 10° to the top row), one row of two MSL-4s with
a 30° horizontal splay angle (hung below lower MSL-6 at
20°), and 650-Ps on the floor. The diagram on the next
page displays connections for half of a complete system;
channels 2, 4, and 6 can be used with identical connections
to create the other half.

The CH 1 Mid-Hi and CH 3 outputs drive the upper and
lower MSL-6 arrays, respectively. Since the coverage
areas of the upper and lower MSL-6 arrays intersect to
some degree, CH 3 is delayed to phase align the upper
and lower systems. The Lo Cut switches for the CH 1
Mid-Hi and CH 3 outputs should be in. The number of
MSL-6s for each row depends on the horizontal coverage
required by the system; each tight-packed unit adds
30°. Refer to the MSL-4 and 650-P Operating Instructions
to design arrays for those speakers.

POLARITY NOTE: The polarity for Meyer self-powered
speakers may be reversed using the input polarity switch
on the user panel. The LD-1A also allows polarity reversal
with the
connected to the DS-2 and Sub outputs. When making
polarity decisions in applications that include the LD-1A,
check the state of all polarity switches.

DS-2 φ

and

Sub φ

switches for speakers

8

650-P Subwoofers

MSL-4 Down-fills

DS-2P

Input Mid-Hi

Output

DS-2

Output

Sub

Output

Input Output

LD-1A

Delay

CP-10 EQ

CH 1

CH 3

Input Output

CH 5

CP-10 EQ

Ch A

A

B

Ch B

MSL-6 Upper

MSL-6 Lower

LD-1A

CH 1

Input Mid-Hi

Output

Output

Input Output

CH 3

Input Output

CH 5

Delay

A

B

Ch A

CP-10 EQ

Ch B

CP-10 EQ

CH 5 controls the MSL-4 down-fill system. Since the
main system is more powerful than the down-fill system
to project farther into the venue, the main system is
audible in the down-fill’s coverage area. To insure that
the systems combine properly in this area:

• Set the MSL-4 to the same polarity as the MSL-6 to
phase align the mid-hi frequencies.

• Use the CH 5 Array EQ filter to minimize the low­mid rise caused by the MSL-4 array.

• Delay the down-fill to align it with the lower
MSL-6 system in their intersecting coverage area.

The polarity for the 650-P depends on the height and
distance of the measurement position from the flown and
subwoofer systems. The entire system should be measured,
phase-aligned, and equalized using the SIM System II
Sound Analyzer and CP-10 Parametric Equalizer.

MSL-6 Upper

Sub

MSL-6 Lower

650-P Subwoofers

MSL-4 Down-fills

Flown MSL-6, DS-2P, and MSL-4;
650-P on the Floor

The system from the previous example can be supple­mented with a row of four DS-2Ps (or PSW-2s), sus­pended below the lower MSL-6 array, to reinforce the
low frequencies. The MSL-4s are hung below the DS-2Ps
at 20°.

The connections for this system are the same as the
previous example except that the CH1 DS-2 output
drives the DS-2P system with the DS-2 & Sub Crossover
switch in. The lower MSL-6 system should be delayed to
align with the upper MSL-6 system in the area in which
their coverage overlaps. The MSL-4 should also be de­layed to align with the lower MSL-6 system.

Refer to the Operating Instructions for the MSL-4, 650-P ,
and DS-2P (or PSW -2) to design arrays for those speakers.

The MSL-6, MSL-4, and DS-2P systems should be set to
the same polarity . The polarity for the 650-P depends on
the height and distance of the measurement position
from the flown and subwoofer systems.

The entire system should be measured, phase-aligned,
and equalized using the SIM System II Sound Analyzer
and CP-10 Parametric Equalizer.

9

Driver Troubleshooting

The Remote Monitoring System (RMS) is the best method
to query the status of the drivers in a system before and
during the performance. RMS monitors peak power,
peak voltage, and average voltage (VU) for each amplifier
channel, allowing immediate detection and muting for
drivers with open or shorted voice coils, with minimal
disruption to the system. Contact Meyer Sound for more
information about RMS.

In the absence of RMS, several methods can be employed
to obtain information about the state of the drivers.

Use a 3/16” hex wrench to remove the nuts that mount
the low driver. Support the driver as the last nut is
removed to prevent it from falling. Twist the driver
sideways and up/down to remove it from the back of
the cabinet.

Verifying Polarity

Incorrect driver polarity impairs system performance
and may damage the drivers. All Meyer Sound loud­speakers are shipped with the drivers in correct align­ment. However, if the driver or circuit wiring has been
removed or disassembled in any loudspeaker in a system
for any reason, check the polarity between adjacent
loudspeakers and between drivers in the same cabinet.

Driver Troubleshooting with TPL

The TPL LEDs can indicate serious driver problems, if
interpreted correctly. If one MSL-6 in a system exhibits
substantially more TPL activity than others receiving
the same audio signal, then one of the drivers corre­sponding to the excessively active LED may have a short
circuit. This is a potentially dangerous condition for the
electronics; shut the MSL-6 down immediately.

The TPL circuit does not activate if there is no power
dissipation in the driver, regardless of the input signal
level. Therefore, if all MSL-6s in a system receiving the
same audio signal exhibit TPL activity except one, then
that unit may have an open voice coil; disconnect it and
contact Meyer Sound for repair information.

Removal, Inspection, and Replacement

To determine whether a low or high frequency driver is
functioning properly , or r eplace a damaged driver , contact
Meyer Sound to obtain the

Evaluation Procedure for Self-Powered Series Products

(part # 17.010.120.01) or the

and Evaluation Procedure for Self-Powered Series
Products

accurate for inspection and verification but have yet to
be updated for the different driver removal procedure
for the MSL-6.

The MSL-6 has two rear hatch covers that must be re­moved to access the high and low drivers. Remove the
screws for either hatch with a Phillips screwdriver. The
hatch is sealed with a rubber gasket so it must be pulled
off with moderate force.

Use a 7/16” open-end wrench to remove the nuts that
secure the high driver to the horn. Hold the driver as the
final nut is removed to prevent it from falling. Twist the
driver sideways and up/down to remove it from the
back of the cabinet.

(part # 17.010.120.02). These documents are

Low Driver Inspection and

High Driver Inspection

We recommend that SIM System II be used to check
polarity but a real-time frequency analyzer with one­third octave resolution is adequate.

!

Since polarity reversal causes excessive driver
excursion at high source levels, use moderate levels
when conducting these tests.

Driver Polarity in the Same Loudspeaker

Use the following test procedure to verify polarity be­tween high frequency horn drivers:

1. Place a monitoring microphone 5 ft from the grill

frame, 8.5” below the top of the speaker, at the mid­point of the center horn (center-line of cabinet).

2. Connect a signal source to the loudspeaker and

note the frequency response.

The polarity of the high drivers is correct if the fre­quency response is ±3 dB 1 – 4 kHz. Polarity reversal for
the center or outer horns is indicated by 12 – 15 dB
cancellation in the same region. Check the wiring to the
high frequency drivers and to the MP-4 and correct the
problem.

Use the following test to verify polarity between low
frequency drivers:

1. Place a monitoring microphone 5 ft from the grill

frame, 28” below the top of the cabinet, at the mid­point between low drivers (center-line of cabinet).

2. Connect a signal source to the loudspeaker and

note the frequency response.

The polarity of the low drivers is correct if the frequency
response is ±3 dB 125 – 500 Hz. Polarity reversal for one
of the low drivers is indicated by 12 – 15 dB cancellation
in the same region. Check the wiring to the low drivers
and to the MP-4 and correct the problem.

10

Use the following test to verify polarity between high
and low frequency drivers:

1. Place a monitoring microphone 5 ft from the grill
frame, 24” below the top of the cabinet, at the mid­point between low drivers (center-line of cabinet).

2. Connect a signal source to the loudspeaker and
note the frequency response.

The polarity is correct if the frequency response is
±3 dB 500 Hz – 1 kHz. Polarity r eversal is indicated by a
6 – 12 dB cancellation in the same range.

Polarity Between Adjacent Loudspeakers

Use the following test procedure to verify the polarity
between adjacent MSL-6 loudspeakers:

1. Position two loudspeakers adjacent to each other.

2. Place a measurement microphone six ft from the
speakers on the axis between them.

3. Connect a signal source to one speaker and note the
frequency response and overall level.

4. Apply the same signal to the second speaker with
the first speaker still connected.

The polarity is correct if the frequency response r emains
constant with a significant increase in amplitude. Broad­band cancellation (decreased overall level) indicates
polarity reversal.

Phase Poppers

We do not recommend using phase poppers to analyze
driver polarity . The phase response for all drivers varies,
to some degree, over the frequency range in which it
operates. Since phase poppers do not discern variations
in phase with respect to frequency, they do not provide
accurate information about the phase response through
the crossover.

Phase poppers are, therefore, not useful for performing
phase measurements on individual loudspeakers or full­range sound systems containing one or more crossovers.
If necessary , apply a phase popper only to loudspeakers
with identical drivers without a crossover, and check
the overall system phase response with a frequency
analyzer and/or listening test.

11

3.1

Dimensions

All units in inches

26.9

14.0

12.5

24.2

1.6

(Rigging Typ, both ends)

Upper & Lower

Braces

3

"-16 Reinforcement

⁄8

Rods, B7 Alloy Steel

Fluid-Cooled High

Frequency Driver,

4-inch Diaphragm

(2-inch Throat)

0.5

C.G.

30.4

29.4 Ref

42.8

7.4

32.2

42.5

Top Front Side

Physical Construction

3

" Steel,

⁄16

ASTM A36

C.G.

22.0

12.5

32.3

Pivoting Lift Ring
1500 lb. Load Capacity,
5:1 Safety Factor
(12 places)

High-Frequency
Horn Section

5

⁄8

" Plywood Sides

3

⁄16

" inch ASTM A36

Steel Support Channel

Fluid-Cooled Back-

Vented 12-inch Cone

Low-Frequency Driver

11 Ga. Steel
Side Braces

Resonance-

Damping Foam

3

" Plywood

⁄8

Top & Bottom

Bracing Fastened With

3

"-16 Grade B Steel

⁄8

Flathead Socket Screws

(32 Total)

12

Flare-Adjusting
Foam Bullet

Low-Frequency
Horn Section

Low-Frequency
Vent

Safety Summary

English Français

• To reduce the risk of electric shock, disconnect the loud-

speaker from the AC mains before installing audio cable.
Reconnect the power cord only after making all signal
connections.

• Connect the loudspeaker to a two-pole, three wire grounding

mains receptacle. The receptacle must be connected to a
fuse or circuit breaker. Connection to any other type of
receptacle poses a shock hazard and may violate local
electrical codes.

• Do not install the loudspeaker in wet or humid locations

without using weather protection equipment from Meyer
Sound.

• Do not allow water or any foreign object to get inside the

loudspeaker. Do not put objects containing liquid on, or
near, the unit.

• To reduce the risk of overheating the loudspeaker, avoid

exposing it to direct sunlight. Do not install the unit near
heat emitting appliances, such as a room heater or stove.

• This loudspeaker contains potentially hazardous voltages.

Do not attempt to disassemble the unit. The unit contains
no user serviceable parts. Repairs should be performed
only by factory trained service personnel.

!

• Pour réduire le risque d’électrocution, débrancher la
prise principale de l’haut-parleur, avant d’installer le
câble d’interface allant à l’audio. Ne rebrancher le bloc
d’alimentation qu’après avoir effectué toutes les connections.

• Branchez l’haut-parleur dans une prise de courant à 3
dérivations (deux pôles et la terre). Cette prise doit être
munie d’une protection adéquate (fusible ou coupe-circuit).
Le branchement dans tout autre genre de prise pourrait
entraîner un risque d’électrocution et peut constituer une
infraction à la réglementation locale concernant les
installations électriques.

• Ne pas installer l’haut-parleur dans un endroit où il y a de
l’eau ou une humidité excessive.

• Ne pas laisser de l’eau ou tout objet pénétrer dans l’haut­parleur. Ne pas placer de r´cipients contenant un liquide
sur cet appareil, ni à proximité de celui-ci.

• Pour éviter une surchauffe de l’haut-parleur, conserver-la
à l’abri du soleil. Ne pas installer à proximité d’appareils
dégageant de la chaleur tels que radiateurs ou appareils
de chauffage.

• Ce haut-parleur contient des circuits haute tension
présentant un danger. Ne jamais essayer de le démonter.
Il n’y a aucun composant qui puisse être réparé par
l’utilisateur. Toutes les réparations doivent être effectuées
par du personnel qualifié et agréé par le constructeur.

Deutsch Español

• Um die Gefahr eines elektrischen Schlages auf ein Mini­mum zu reduzieren, den Lautsprecher vom Stromnetz
trennen, bevor ggf. ein Audio-Schnittstellensignalkabel
angeschlossen wird. Das Netzkabel erst nach Herstellung
aller Signalverbindungen wieder einstecken.

• Der Lautsprecher an eine geerdete zweipolige Dreiphasen­Netzsteckdose anschließen. Die Steckdose muß mit einem
geeigneten Abzweigschutz (Sicherung oder
Leistungsschalter) verbunden sein. Der Anschluß der
unterbrechungsfreien Stromversorgung an einen anderen
Steckdosentyp kann zu Stromschlägen führen und gegen
die örtlichen Vorschriften verstoßen.

• Der Lautsprecher nicht an einem Ort aufstellen, an dem
sie mit Wasser oder übermäßig hoher Luftfeuchtigkeit in
Berührung kommen könnte.

• Darauf achten, daß weder Wasser noch Fremdkörper in
das Innere den Lautsprecher eindringen. Keine Objekte,
die Flüssigkeit enthalten, auf oder neben die
unterbrechungsfreie Stromversorgung stellen.

• Um ein Überhitzen dem Lautsprecher zu verhindern, das
Gerät vor direkter Sonneneinstrahlung fernhalten und
nicht in der Nähe von wärmeabstrahlenden
Haushaltsgeräten (z.B. Heizgerät oder Herd) aufstellen.

• Im Inneren diesem Lautsprecher herrschen potentiell
gefährliche Spannungen. Nicht versuchen, das Gerät zu
öffnen. Es enthält keine vom Benutzer reparierbaren Teile.
Reparaturen dürfen nur von ausgebildetem
Kundenienstpersonal durchgeführt werden.

• Para reducir el riesgo de descarga eléctrica, desconecte de
la red el altoparlante antes de instalar el cable de
señalización de interfaz de la segnale. Vuelva a conectar el
conductor flexible de alimentación solamente una vez
efectuadas todas las interconexiones de señalizatción.

• Conecte el altoparlante a un tomacorriente bipolar y trifilar
con neutro de puesta a tierra. El tomacorriente debe estar
conectado a la protección de derivación apropiada (ya sea
un fusible o un disyuntor). La conexión a cualquier otro
tipo de tomacorriente puede constituir peligro de descarga
eléctrica y violar los códigos eléctricos locales.

• No instale el altoparlante en lugares donde haya agua o
humedad excesiva.

• No deje que en el altoparlante entre agua ni ningún objeto
extraño. No ponga objetos con líquidos encima de la
unidad ni cerca de ella.

• Para reducir el riesgo de sobrecalentamiento, no exponga
la unidad a los rayos directos del sol ni la instale cerca de
artefactos que emiten calor, como estufas o cocinas.

• Este altoparlante contiene niveles de voltaje peligrosos en
potencia. No intente desarmar la unidad, pues no contiene
piezas que puedan ser repardas por el usuario. Las
reparaciones deben efectuarse únicamente por parte del
personal de mantenimiento capacitado en la fábrica.

13

R

T

H

E
U

A

P
E

w
a

o

s
o

t

r

e

e
u
u

c

Mains circuit
breakers

High Limit (red)

Low Limit (red)

Power LED (green/red)

Input polarity switch

Signal input and

loop connectors

Remote Monitoring
System panel
(if RMS is installed)

10K

Ω

Balanced

MSL-6

VHF Limit

HI Limit

LO Limit

Active / Speaker Fault
Input Polarity

ESD

Earth / Chassis

Controls and Connectors

S

H

U

P

R

T

E

I

-

-

C

K

I

R

S

H

U

P

R

T

E

I

-

-

C

K

I

R

PUSH

2 +
3 +

1

220K

Ω

2

3

Case

Input

Rear User Panel shown with the optional
Remote Monitoring System (RMS) panel

2

1

1

3

Loop

Service

Wink

Remote Monitoring System

Reset

Activity

Network

!

WARNINGS:
THIS PRODUCT MUST BE GROUNDED

This surface may reach high temperatures while in use.
To ensure proper operation, allow at least 6 inches
clearance from this surface and adequate ventilation.
To reduce the risk of electric shock do not remove cover.
No operator serviceable parts inside.
Refer servicing to qualified personnel.
To reduce the risk of fire or electric shock
do not expose this appliance to rain or moisture.

ATENCIÓN

:

ACCESO INTERNO SOLO

AUTORIZADO A PERSONAL TÉCNICO CALIFICADO

ACHTUNG

:

GEHÄUSE NICHT ÖFFNEN WARTUNG

UND REPARATUR NUR DURCH ELEKTROFACHKRÄFTE

ATTENTION

:

ENTRETIEN ET REPARATIONS
INTERNES NE SONT AUTORISEES QU'AU
PERSONNEL TECHNIQUE QUALIFIÉ

UK WARNING

:

NO OPERATOR SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED PERSONNEL

THIS APPARATUS MUST BE EARTHED.

Auto-Voltage Select
95-125V

~

208-235V
50-60Hz
1400W RMS MAX

Meyer Sound, Berkeley, CA. USA

~

50-60Hz

1400W RMS MAX

Mains AC inlet

Tie-wrap anchor

S

H

U

P

R

T

E

I

-

-

C

K

I

R

S

H

U

P

R

T

E

I

-

-

C

K

I

R

PUSH

2

1

2

1

3

3

Input

Loop

European Rear User Panel

with IEC 309 connector

Contact Information

Meyer Sound Laboratories, Inc.

2832 San Pablo Avenue
Berkeley, California 94702
Telephone: 510 - 486 - 1166
FAX: 510 - 486 - 8356
E-mail: [e-mail]
http://www.meyersound.com

Service

Wink

Reset

Activity

Remote Monitor System

Network

!

WARNINGS:
THIS PRODUCT M

This surface may reach high t
To ensure proper operation, allo
clearance from this surface and
To reduce the risk of electric sh
No operator serviceable parts in
Refer servicing to qualified pers
To reduce the risk of fire or elec
do not expose this appliance to

ATENCIÓN: ACCESO INTE

AUTORIZADO A PERSONAL

ACHTUNG: GEHÄUSE NIC

UND REPARATUR NUR DURC

ATTENTION: ENTRETIEN

INTERNES NE SONT AUTORI
PERSONNEL TECHNIQUE QU

UK WARNING: THIS APPA

NO OPERATOR SERVICEABLE
REFER SERVICING TO QUALIFI

Auto-Voltage Sele
10A RMS
20A Peak
88-127V

~

50-60Hz
700W RMS MAX

Operational voltag
Turn on 80V~ T
Turn on 160V~ T

Meyer Sound, B

Meyer Sound Germany
Gmbh

Carl Zeiss Strasse 13
56751 Polch, Germany
Telephone: [phone]
FAX: [phone]

14