Meyer Sound LD-1A Operating Instructions Manual

Operating Instructions

LD-1A

Line Driver

Patents Pending

LD-1A Line Driver

+

15V

-

Power

LD-1A Front Panel

PUSH

Input

PUSH

Mid-Hi Out

LD-1A Rear Panel

CH 1

Mute

Master

0

-3

+3

-6

DS-2

-9
+6

-12

Lo Cut

Array

EQ

Mute

Sub

Mid-Hi

0

-3

+3

-6

-9
+6

-12

Channel 1

DS-2 Out Sub Out Loop

Channel 2

Signal Mute-ClipSignal Mute-Clip

DS-2

φ

Master

Mute

0

-3

+3

-6

-9
+6

-12

DS-2
& Sub
Crossover

Sub

φ

Mute

Mid-Hi

0

-3

+3

-6

-9
+6

-12

CH 2

Mute Mute Mute

0

-3

+3

-6

DS-2

-9
+6

-12

-3

-6

-9

-12

Lo Cut

Array

EQ

Mute

Sub

0

-3

-3

+3

-6

-6

-9

-9
+6

-12

-12

Signal Mute-Clip

φ

DS-2

Master

-6

Mute

0

+3

+6

DS-2
& Sub
Crossover

Sub

φ

Mute

0

+3

+6

PUSH

Input Output

PUSH

-3

-9

-12

CH 3

0

+3

+6

Lo Cut

Array

EQ

Channel 3

Channel 4

CH 4

Signal Mute-Clip

Master

0

-3

-6

-9

-12

Lo Cut

Array

+3

+6

EQ

PUSH

Input Output

PUSH

Mute

Active Mute

φ

Polarity

0

Crossover

Sub DS-2 & Sub

Lo Cut

Out In

Array EQ

Out In

Channel 5

Channel 6

CH 5

Signal Mute-Clip

Master

0

-3

-6

-9

-12

180

CH 6

Signal Mute-Clip

Mute Mute Mute

Master

0

-3

+3

-6

-9

+6

-12

Lo Cut

Array

EQ

Channel 7

PUSH

Input Output

PUSH

Channel 8

Lo Cut

Array

+3

+6

EQ

CH 7

Signal Mute-Clip

Master

-3

-6

-9

-12

CAUTION:

T250mA - 250V FUSE

90-125/180-250 V
50-60 Hz 25W MAX

0

CH 8

Signal Mute-Clip

Master

-3

+3

-6

-9

+6

-12

Lo Cut

Array

EQ

CAUTION:

Set voltage before
applying power.

AC Voltage Ranges

RISK OF FIRE REPLACE WITH

~

0

Mute

Lo Cut

Array

+3

+6

EQ

180-250V

90-125V~

~

Copyright © 1997

Meyer Sound Laboratories, Inc.

All rights reserved

Part #: 05.037.002.01 Rev B2

Symbols Used

UU

LL

CC

UU

LL

®®

LISTED

3K59

COMMERCIAL

AUDIO SYSTEM

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

rÈsultant de tensions

dangereuses

Zu die gefahren von

gef‰hrliche 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

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:

Frame or chassis

Masse, ch‚ssis

Rahmen oder chassis

Armadura o chassis Tierra proteccionista

Protective earth ground

Terre de protection

Die schutzerde

declares that the product:The Manufacturer:

Product Name: LD-1A
Product Options: All

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.

1.0 kV Power Lines

Office of Quality Manager

Berkeley, California USA

April 1, 1997

Made by Meyer Sound Laboratories
Berkeley, California USA

European Office:
Meyer Sound Lab. GmbH
Carl Zeiss Strasse 13
56751 Polch, Germany

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]
www.meyersound.com

Environmental Specifications for

Meyer Sound Electronics Products

Operating temperature: 0 C to +45 C
Non-operating temp: < ñ40 C or > +75 C
Humidity: to 95% at 35 C
Operating altitude: to 4600 m (15,000 ft)
Non-operating altitude: to 6300 m (25,000 ft)

Shock: 30 g 11 msec half-sine

on each of 6 sides

Vibration: 10 ñ 55 Hz (0.010 m

peak-to-peak excursion)

Meyer Sound Germany GmbH

Carl Zeiss Strasse 13
D-56751 Polch, Germany
Telephone: [phone]
FAX: [phone]
Email: [e-mail]

2

Contents

LD-1A Signal Flow Diagram................................ 3

Introduction......................................................... 4

Audio Input ......................................................... 4

AC Power ............................................................. 4

Main Channels 1 and 2 ........................................ 5

LD-1A Signal Flow Diagram

SIGNAL

& CLIP

DETECTOR

Common mode:

Input
10 kW

425 kHz low-pass

Normal mode:
142 kHz low-pass

XLR

3

2

1

fc

RF & ESD
FILTER

80 dB CMRR
Laser Trimmed

DIFF

AMP

Master
Level

-12 to +6 dB

Auxiliary Channels 3-8 ............................................ 6

Example Configurations .. ........................................7

Safety Summary ..................................................... 9

Specifications .......................................................10

GRN
RED

LED

MUTE SWITCHES

Master Mute
Switch

Earth and Chassis GND

power supply board

Full range

Low-cut

160Hz

Q=0.8

-12 dB/oct

Channels 1& 2 only

80Hz
Elliptical

65Hz
Q=0.9

-12 dB/oct

10 W on

Full range

Crossover

DS-2 & Sub
Crossover

Full range

Crossover

Audio GND

Ð6 dB at
220Hz;

0.6 octave
bandwidth

ArrayEQ

DS-2
Level

-12 to +6 dB

Sub
Level

-12 to +6 dB

Flat

DS-2 Mute
Switch

Sub Mute
Switch

Channels 1& 2

Mid-Hi
Level

-12 to +6 dB

only

Mid-Hi Mute
Switch

Polarity
normal

Polarity
inverted

Polarity
normal

Polarity
inverted

High Current

DIFFERENTIAL

DRIVER

High Current

DIFFERENTIAL

DRIVER

High Current

DIFFERENTIAL

DRIVER

PWR-ON

PWR-OFF

MUTE

PWR-ON

PWR-OFF

MUTE

PWR-ON

PWR-OFF

MUTE

XLR

RF

BLOCK

Earth and Chassis GND

RF

BLOCK

Earth and Chassis GND

RF

BLOCK

Earth and Chassis GND

XLR

XLR

3

2

1

3

2

1

3

2

1

DS-2 or
2nd Sub
Output

Sub
Output

Mid-Hi
Output

3

Introduction

g

h

Audio Input

The Meyer LD-1A Line Driver combines functions
previously accessed on the control electronics units for
externally amplified Meyer loudspeakers with new
features, and locates them in a self-contained device
accessible to the sound engineer during setup and
performance. The LD-1A

• integrates different types of Meyer self-powered
speakers into a full-range main system;

• provides gain, mute, and optimized EQ controls
for six auxiliary systems;

• maintains signal integrity for long cable paths.

Channels 1 and 2, equipped to control the main system,
each have:

• a gain control, mute switch, and crossover
function;

• separate Mid-Hi, DS-2 (mid-bass), and Sub
output controls;

• a male XLR Loop connector to route the input
signal to an auxiliary channel or another device.

The six auxiliary channels (3–8) control down-fill, front­fill, and delay systems. Auxiliary channels can also be
used to divide a main system into subsystems, allowing
independent signal levels for speakers directed at different
audience locations. Each auxiliary channel has a mute
switch, gain control, and Lo Cut and Array EQ filters. All
eight channels are fully independent from each other.

The LD-1A occupies two rack spaces and is constructed
with a 16-gauge steel chassis and 1/8” aluminum rack
ears. This rugged design provides protection from
accidental impact, magnetic isolation from nearby
devices, and EMI immunity.

Meyer Speaker Types

The following Meyer self-powered speakers are mentioned
in this document.

MSL-4 Self-powered mid-hi speaker

CQ Series Self-powered mid-hi speaker

DS-2P Self-powered mid-bass speaker

650-P Self-powered subwoofer

PSW-2 Self-powered subwoofer

The LD-1A presents a 10 kOhm balanced input imped­ance to a three-pin XLR connector wired with the follow­ing convention:

Case — Earth (AC) ground and chassis

Pin 1 — Earth (AC) ground and chassis

Pin 2 — Signal

Differential Inputs

Pin 3 — Signal

The LD-1A is balanced in and out, and consequently has
no hot (+) pin. Pins 2 and 3 carry the input as a differential
signal. Use standard audio cables with XLR connectors
for balanced signal sources.

The audio input signal should always be applied between
pins 2 and 3. Pin 1 is connected to chassis and acts as a
safety and current bleed to earth for the EMI and ESD
interference coupled onto the shield of the input cable.
Pin 1 is therefore a noisy ground, and connecting an audio
signal between pins 1 and 2, or pins 1 and 3, results in
a noisy audio signal.

Most modern balanced audio sources (electronically
balanced or transformer output) conform to the wiring
convention described above and interface correctly with
the LD-1A. However, an audio source may produce noise
if it connects pin 1 to a quiet internal audio ground, and
is then connected to pin 1 of the LD-1A (chassis/earth).
To alleviate this noise, try disconnecting pin 1 (or the
cable shield) of the audio source.

To connect an unbalanced audio source to the LD-1A,
use the following wiring connections:

Tip is

Tip is

positive

positive

terminal

terminal

RCA output

RCA output

jack

jack

–

+

+

–

Ring is

Ring is

negative

negative

terminal

terminal

–

–

••

••

Connect shield to – terminal (ring

Connect shield to – terminal (ring)

if the source equipment is floatin

if the source equipment is floating.

Do not connect the shield if the

Do not connect the shield if the

source is grounded.

source is grounded.

shield

shield

LD-1A input

LD-1A input

XLR

XLR

3

3

2

2

1

chassis/earth

1

terminal

chassis/eart
terminal

4

AC Power

Mute

CH 1

Sub

φ

DS-2
& Sub
Crossover

DS-2

φ

Mute

Mute

Mute

Array

EQ

Lo Cut

CH 2

DS-2
& Sub
Crossover

Mute

Mute

Signal Mute-ClipSignal Mute-Clip

Master

-12

-6

-3

0

+3

+6

-9

DS-2

Mid-Hi

Sub

Array

EQ

Lo Cut

Master

Mid-Hi

-12

-6

-3

0

+3

+6

-9

-12

-6

-3

0

+3

+6

-9

-12

-6

-3

0

+3

+6

-9

-12

-6

-3

0

+3

+6

-9

Sub

φ

Mute

Sub

-12

-6

-3

0

+3

+6

-9

-12

-6

-3

0

+3

+6

-9

Mute

DS-2

φ

DS-2

-12

-6

-3

0

+3

+6

-9

Main Channels 1 and 2

AC Inlet and Voltage Select Switch

The LD-1A uses an international standard IEC 320
Mains AC inlet. This convenient rear panel receptacle
accepts many power cord types for mains outlets used
throughout the world. The LD-1A must have the correct
power cord for the AC power in the area in which it will
be used.

The LD-1A operates in two AC voltage ranges: 90 – 125 V
and 180 – 250 V, at 50 or 60 Hz. The voltage select switch
on the rear panel must be set to the proper voltage before
applying AC power. Connecting the LD-1A to a 225 V
AC source with the voltage select switch in the 90 – 125
V position could blow the fuse. Unplug the power cord

before changing the voltage select switch!

CAUTION:

Set voltage before
applying power.

AC Voltage Ranges

180-250V

~

90-125V~

CAUTION:

RISK OF FIRE REPLACE WITH

T250mA - 250V FUSE

90-125/180-250 V
50-60 Hz 25W MAX

~

The audio outputs are muted internally during normal
power on and off, and in case of sudden loss of AC power
or unstable line voltage. This precaution prevents noise
transmission, and possible damage, to interconnected
devices.

Donít use a ground-lifting adapter or cut the AC ground pin.

Voltage select
switch

IEC 320
male power inlet

Channels 1 and 2 are equipped to control a full-range
main system. Each channel has a Signal/Mute-Clip LED
indicator, mute switch, gain control, Mid-Hi, DS-2, and
Sub output controls, and a male XLR Loop connector.

The Master gain control sets the channel’s overall level.
The Mute switch mutes the entire channel. The bicolored
Signal/Mute-Clip LED indicates input signal presence
and level with a variable intensity green color, and clipping
or mute with red. The Loop connector is used to send the
input signal to an auxiliary channel or to another device.

The Mid-Hi, DS-2 (mid-bass), and Sub outputs each have
a level control and mute switch. The level control modifies
the level set by the channel’s Master gain control; the
mute switch affects the Mid-Hi, DS-2, or Sub output only.
For example, the Mid-Hi output could be muted without
affecting the Loop, Sub, or DS-2 outputs. Additional
functions specific to each output are described in the
following sections.

To avoid electrical shock and damage to the unit, use the
power cord specified by Meyer Sound or an equivalent
that satisfies the requirements of the local safety testing
agency. Do not operate the unit if the power cables are
frayed or broken.

AC Fuse

Always disconnect the power cord before changing the
fuse. To replace the fuse, insert a flat-blade screwdriver
in the fuse cap and gently turn counterclockwise; the
fuse springs from its socket. Replace only with a 5 x 20 mm,
T 250 mA, 250 V, time-lag fuse that conforms to identical
safety agency standards. If the fuse blows again, contact
Meyer Sound for repair information.

5

Mid-Hi Output

The Mid-Hi output has two switch-activated, optimized
filters. Pushing the Lo Cut switch in activates a high­pass filter (160 Hz, Q = 0.8, –12 dB/octave) that performs
a crossover function for the Mid-Hi output. The filter is
bypassed with the switch out.

Pushing the Array EQ switch in activates a filter (6 dB cut
at 220 Hz, 0.6 octave bandwidth) to equalize the low­mid rise produced by three to five horizontally arrayed
MSL-4s. The filter is bypassed with the switch out.

Auxiliary Channels 3-8

The six auxiliary channels 3–8 control down-fill, front­fill, and delay systems. Each channel has a Signal/Mute­Clip indicator, gain control, mute switch, and Lo Cut and
Array EQ filters, all of which are explained in the previous
section.

Channels 3–8 are identical; channels 4 and 5 are shown
below.

NOTE: The Array EQ filter compensates for MSL-4 array
characteristics in free-space. We recommend using the
Meyer SIM System II Sound Analyzer and CP-10 Paramet-
ric Equalizer to measure and correct problems caused by
the acoustical environment.

It is important to note that the Mid-Hi output produces a
full-range signal when both the Array EQ and Lo-Cut
filters are out (bypassed).

DS-2 and Sub Outputs

The DS-2 & Sub Crossover network, optimized for the
DS-2P and 650-P (or PSW-2), is composed of a low-pass
and an elliptical filter. Pushing the switch in activates
the two-way crossover, sending frequencies below 80 Hz
to the Sub output and above 80 Hz to the DS-2 output.

With the switch out, a full-range signal is sent to both the
DS-2 and Sub outputs. When the DS-2P is used alone as
a subwoofer, or is not included in the system, the switch
should be out.

NOTE: Full-range signals may be applied to Meyer self­powered subwoofers because they have built-in active
crossovers that filter mid-hi frequencies; external cross­overs are unnecessary.

The DS-2 and Sub outputs each have a polarity toggle
(DS-2 φ, Sub φ). With the switch out, the polarity is set to
0°. Pushing the switch in inverts the polarity 180° with
respect to the out position.

CH 4

Signal Mute-Clip

-9

-12

Mute

0

-3

+6

Lo Cut

Array

EQ

Master

-6

+3

Mute

Active Mute

φ

Polarity

0

180

Crossover

Sub DS-2 & Sub

Lo Cut

Out In

Array EQ

Out In

CH 5

Signal Mute-Clip

-9

-12

Mute

0

-3

+6

Lo Cut

Array

EQ

Master

-6

+3

Auxiliary channels 4 and 5 with switch function summary.

The auxiliary channels can also divide the main system
into separate subsystems. For example:

1. Route the CH 1 input signal to CH 3 using the
CH 1 Loop connector.

2. Connect the CH 3 output to the outer two elements
of an array of five mid-hi speakers.

3. Connect the Mid-Hi output to the inner three
elements of the mid-hi array.

Using main and auxiliary channels to apply separate
levels for the edge and internal elements of a mid-hi
system is incorportated into an example configuration
on page 8.

6

Example Configurations

Although a typical MSL-4: PSW-2 ratio is 2:1, the Sub and
Mid-Hi gain controls allow the ratio to vary while main­taining control of the spectral balance of the system.

This section demonstrates the flexibility and utility of the
LD-1A with four example applications.

Speaker Placement and Polarity

The cabinets in the following example configurations are
in a close-proximity coplanar orientation, unless other­wise stated. Placing speakers more than 5 feet apart may
require setting them to opposite polarities to compensate
for the propagation delay between speakers.

Measurement and Correction

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.

The 650-P can be used interchangeably with the PSW-2
but the 650-P’s larger size precludes tight-packing
configurations with the MSL-4; the 650-P also lacks
rigging hardware.

MSL-4, DS-2P, and 650-P

Adding the DS-2P to an MSL-4/650-P system enhances
LF power and clarity. With the DS-2 & Sub Crossover
switch in, the DS-2 and Sub outputs each receive signals
optimized for the frequency response capabilities of the
DS-2P and 650-P.

The MSL-4 is driven from the CH 1 Mid-Hi output with
the Lo Cut filter in to minimize the overlap in frequency
response with the DS-2P and 650-P. Set the 650-P to the
opposite polarity to the MSL-4 and DS-2P.

Mid-Hi

DS-2

DS-2P/
DS-4P

Contact Meyer Sound for assistance with your application.

MSL-4 and PSW-2

The MSL-4 and PSW-2 form a compatible full-range
system. However, due to an overlap in LF ( low frequency)
response between the two speakers, there is a rise in the
system frequency response in the range 65–120 Hz. It is
important to emphasize that the speakers are in phase in
this region. The rise can be eliminated by activating the
Lo Cut filter for the Mid-Hi output, if desired.

Set the MSL-4 and PSW-2 to the same polarity.

650-P

Set the 650-P to the opposite polarity to the DS-2P and
MSL-4.

7

PSW-2 Flown with MSL-4;
650-P on the Floor

Including subwoofers in a flown cluster provides a
smooth frequency image because the low and mid-hi
frequencies are produced from speakers located close
together. The identical dimensions of the PSW-2 and
MSL-4 allow them to be easily flown together.

The CH 1 Mid-Hi output drives the MSL-4 with the
Lo Cut filter in. The CH 1 Sub and DS-2 outputs drive
the 650-Ps and PSW-2s with the DS-2 & Sub Crossover
switch out, sending a full-range signal to each speaker
with independent levels.

MSL-4 and
PSW-2
flown in

CH 1 Mid-Hi

CH 1 Input CH 1 DS-2

LD-1A

Line Driver

CH 1 Sub

same cluster

650-P
subwoofer
on the floor

The CH 1 DS-2 and Sub outputs drive the DS-2P and 650­P systems with the DS-2 & Sub Crossover switch in. Set
the MSL-4 and DS-2P to the same polarity. The polarity of
the 650-P depends on the height and distance of the mea­surement position from the subwoofer and flown systems.

CH 5 controls the CQ 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 speakers
combine properly in the intersecting coverage area:

• Set the CQ to the opposite polarity to the MSL-4 to
phase align the mid-hi frequencies and minimize
the MSL-4’s LF down-lobe.

• Use the CH 5 Lo Cut filter to eliminate the LF rise
caused by the overlap in frequency response with
the 650-P and DS-2P systems.

• Delay the down-fill to compensate for the propa­gation delay between the down-fill and main
systems in the intersecting coverage area.

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

Set the MSL-4 and PSW-2 to the same polarity. The
polarity of the 650-P depends on the height and distance
of the measurement position from the subwoofers and
flown cluster.

MSL-4, DS-2P, 650-P with CQ Down-fill

This example shows the LD-1A integrating a complete
system of self-powered speakers for a large venue.
The diagram shows half of the system using channels 1,
3, and 5; identical connections can be used for channels 2,
4, and 6 to create the other half. The MSL-4, DS-2P, and CQ
arrays are flown; the 650-Ps are on the floor.

The CH 1 Mid-Hi and CH 3 outputs drive the inner three
and outer two speakers of the MSL-4 array, applying
appropriate levels for speakers directed at different
distances. The diagram shows the additional mid-hi
output created by connecting the CH 1 Loop to the CH 3
input. Using a Y-connection at the CH 1 input (as shown
for the CQ down-fills) accomplishes the same signal
routing. The Lo Cut and Array EQ switches for CH 1
and 3 should be in. The Lo Cut filters eliminate the LF
rise caused by the overlap in frequency response between
the MSL-4 and DS-2P/650-P systems. The Array EQ
filters minimize the MSL-4 array’s low-mid rise.

Set the MSL-4 and DS-2P to the same polarity; reverse the
polarity of the CQ. The polarity of the 650-P depends on the
distance of the measurement position from the subwoofer
and flown systems.

8

Safety Summary

!

English

• To reduce the risk of electric shock, disconnect the LD-1A
from the AC mains before installing audio cable. Reconnect
the power cord only after making all signal connections.

• Connect the LD-1A 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 allow water or any foreign object to get inside the
LD-1A . Do not put objects containing liquid on, or near,
the unit.

• To reduce the risk of overheating the LD-1A, avoid exposing
it to direct sunlight. Do not install the unit near heat
emitting appliances, such as a room heater or stove.

• The LD-1A 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.

Français

• Pour réduire le risque d’électrocution, débranchez la prise
principale de l’haut-parleur, avant d’installer le câble
d’interface allant à l’audio. Ne rebranchez 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 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, conservez-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

• 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.

• 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.

Español

• 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 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.

9

Specifications

Architecture

Main (Channels 1, 2)

Master Gain Control -12 to +6 dB
Mid-Hi, DS-2, Sub Gain Controls -12 to +6 dB
Low-cut Filter for Mid-Hi Output 160 Hz high-pass, -12 dB/octave, Q = 0.8
Array EQ Filter for Mid-Hi Output 6 dB cut at 220 Hz, 0.6 octave bandwidth
Mute Mute switches for Master, Mid-Hi, DS-2, and Sub outputs
Polarity Toggles for Sub and DS-2 outputs

Auxiliary (Channels 3-8)

Gain Control -12 to +6 dB
Low-cut Filter 160 Hz high-pass, -12 dB/octave, Q = 0.8
Array EQ Filter 6 dB cut at 220 Hz, 0.6 octave bandwidth
Mute Mutes the channel output

Audio Inputs

Connector 1 female XLR per channel
Type Differential balanced input circuit
Impedance 10 k differential (between pins 2 and 3)
Wiring Pin 1: chassis/earth ground; Pin 2: signal; Pin 3: signal
RF Filter Common Mode: 425 kHz low-pass; Differential Mode: 142 kHz low-pass
Common Mode Rejection Ratio > 80 dB (typically 90 dB); measured in the range 50 Hz -1 kHz

Signal Presence LED (Variable intensity; monitored at the input for each channel)

Threshold -26 dBV (50 mVrms) pink noise or sinewave
Full Intensity -10 dBV (300 mVrms) pink noise or sinewave

Audio Outputs

Type Balanced, cross-coupled simulated transformer topology
Impedance 50 Ohm balanced (between pins 2 and 3)
RF Filter Pins 2 and 3 shunted to chassis via 500 pF capacitance

Connectors

Main 4 female XLR/channel (Mid-Hi, DS-2, Sub, Loop)
Auxiliary 1 female XLR/channel
Wiring Pin 1: chassis/earth ground; Pin 2: signal; Pin 3: signal

Drive Capability

Maximum Voltage

Maximum Current ±70 mApk (10 Vrms into 200 Ohm)
Cables and Load Drives > 100,000 pF (> 1000 ft cable) without instability or distortion

1

600 Ohm Load: ±22.5 Vpk (+24 dBV, +26.2 dBu sinewave)

No Load: ±25.0 Vpk (+25 dBV, +27.2 dBu sinewave)

AC Power

Connector IEC 320 (line, neutral/line, earth)
Operating Voltage 90 - 125 VAC / 180 - 250 VAC (selectable with rear panel switch); 50/60 Hz
Maximum Power 25 Watts; Fuse: 5 x 20 mm, T 250 mA, 250 V, time-lag

Audio Performance

Frequency Response < ±0.2 dB 20 Hz - 20 kHz
Bandwidth DC to 60 kHz (-3dB)
Phase Response < ±3° from pure 3 µsec delay (DC - 20 kHz)
Dynamic Range
Noise Floor
THD + N
Gain Accuracy < ±0.15 dB at +6 dB gain; < ±0.25 dB at 0 dB gain
Mute Attenuation > 100 dB

Gain Range

Main Channels -24 to +12 dB
Auxiliary Channels -12 to +6 dB

2

3

4

> 120 dB
> -95 dBV A-weighted; > -90 dBV un-weighted
< 0.005% (typically 0.002%)

Physical

Dimensions Height: 3.45 inches (2 rack spaces); Width: 16.75 inches; Depth: 6.96 inches
Weight 13.5 lb (6.1 kg); shipping: 15 lb (6.8 kg)
Enclosure/Finish Black 16-gauge steel chassis; 1/8 inch aluminum rack ears

Notes

1. 0 dBV = 1 Vrms; 0 dBu = 0.775 Vrms; 0 dBm = 1 mWrms

2. Ratio of maximum sinewave to A-weighted noise floor.

3. Level set to unity gain (0 dB).

4. 0 dBV, 1 kHz sinewave input. Gain at +12 dB main
channel, +6 dB auxiliary channel.

10