Meyer Sound LD-2 User Manual

80Hz between the Mid-Bass
and Sub outputs. With the
switch out, a full range signal is
sent to both sections. Polarity
switches in both the Mid-Bass
and Sub sections allow quick
correction of any polarity
reversal or allignment
optimization problems. If only
full range and subwoofers are
used in the main system, the
Mid-Bass/AUX section is
available for auxiliary systems
such as front-fill, down-fill or
delays.

A Master section includes a
gain control, a master Mute
switch with LED, and a signal
presence/clip LED. The
compact, single rack space
cabinet is made of 16-gauge
steel to provide magnetic
isolation from nearby devices,
EMI immunity and protection
from accidental impact damage.

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The LD-2 provides an
alternative to the larger LD-1A
line driver in applications where
coverage is supplied primarily
by the main Left and Right
systems, with or without
subwoofers, and few (if any) fill
or auxiliary subsystems are
used. Typical systems using the
LD-2 could include concert halls
and performing arts centers,
nightclubs, houses of worship,
corporate presentations, and
touring systems for small to
mid-sized venues.

The LD-2 is a compact, one
rack space device designed
specifically for integrating
different types of Meyer Sound
self-powered loudspeakers into
an optimized full-range system.
As a line driver, the LD-2 can
connect to cable runs of up to
1000 feet without introducing
instability or distortion. In
addition, the LD-2 incorporates
a number of switching and filter
options to facilitate quick set­up and accommodate a variety
of different system
configurations.

Each channel of the LD-2
includes three output/control
sections, designated Mid-Hi,
Mid-Bass/AUX and Sub. Each
section provides a gain control
(-12 to +6dB) and Mute switch
with LED. In addition, the Mid­Hi section has an Array EQ filter
to minimize the low-mid rise
caused by horizontal arrays of
three to five MSL-4 speakers;
and Low Cut filter which
performs a crossover function
by either sending a full range
signal to the Mid-Hi output or
rolling off at 160Hz
(12dB/octave). The Mid­Bass/AUX section also includes
a low cut filter (160Hz,
12dB/octave). A separate Mid­Bass and Sub Crossover switch
enables the LD-2 to
accommodate either Mid-Bass
or Subwoofers or both Mid­Bass and Subs, in the same
system. With the switch
engaged, the signal divides at

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The line driver shall be a
two channel device with one
input and three outputs for
each channel (Left and Right).
Each channel shall provide
dedicated control sections and
outputs for Mid-Hi powered
loudspeakers, Mid-Bass
powered loudspeakers or an
auxiliary system, and powered
Subwoofers. The Mid-Hi control
section shall provide gain
control over a -12 to +6dB
range, a Mute switch, a Low cut
filter (160Hz) and an Array EQ
filter (-6dB at 220Hz, 0.6 octave
bandwidth). The Mid-Bass or
Aux section shall provide gain
control over a -12 to +6dB
range, a Mute switch, Low cut
filter (160Hz), and polarity
switch. The Subwoofer section
shall provide gain control over
a -12 to +6dB range, Mute
button, and polarity switch. A
Mid-Bass & Sub Crossover
Switch at 80Hz shall allow use
of either Mid-Bass or Sub for LF
reproduction, or both. Each
channe shall include a master
gain control over a -12 to +6dB
range, a signal presence/clip
LED indicator, master Mute
button, and an LED mute
indicator. All outputs shall be
on XLR-M connectors, and each
shall have an output
impedance of 10

Ω and provide

a maximum output voltage of
±22.5Vpk. Inputs shall be
XLR-M connectors with a 10k
impedance. An internal power
supply shall be switchable for
120V or 230V nominal
operation on 50 or 60Hz line
current. The line driver shall
be housed in a 16-gauge steel,
1U rack mount chassis.
The line driver shall be a Meyer
Sound LD-2.

Superior
engineering
for the art
and science
of sound.

www.meyersound.com

FEATURES

PRELIMINARY

LD-2Line Driver

Integrates different
self-powered speakers

+

φ φ

Mid-Bass or AUX

0 180

PUSH PUSH

LD-2 Front Panel

LD-2 Rear Panel

Maintains signal integrity
over long cable paths

Separate Mid-Hi,
Mid-Bass/AUX and
Subwoofer output controls

Optimized filters to
accommodate specific
array configurations

Master Left and Right Gain Controls

Mid-Hi, Mid-Bass/Aux, Sub Gain Controls

Low-cut Filter for Mid-High & Mid-Bass/Aux Output

Array EQ Filter for Mid-Hi Output

Mute

Polarity

Connector

Type

Impedance

Wiring

RF Filter

Common Mode Rejection Ratio

Signal Presence/clip LED

LED Threshold

LED Full Intensity

Type

Impedance

RF Filter

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CONNECTORS Main

Wiring

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DRIVE CAPABILITY Maximum Voltage

Maximum Current

Cables and Load

Connector

Operating Voltage

Maximum Power

Frequency Response

Bandwidth

Phase Response

Dynamic Range

2

Noise Floor

3

THD + N

4

Gain Accuracy

Mute Attenuation

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GAIN RANGE Each Channel

Auxiliary Channels

Dimensions

Weight

Enclosure/Finish

Meyer Sound Laboratories, Inc.

2832 San Pablo Avenue
Berkeley, CA 94702
tel: [phone]
fax: [phone]
e-mail: [e-mail]
http: www.meyersound.com

© 2000 Meyer Sound Laboratories, Inc.

All rights reserved

Meyer Sound reserves the
right to alter any specification
without notice.

Please visit our web site at
www.meyersound.com for
up-to-date information.

Meyer Sound Laboratories

has devoted itself to

designing, manufacturing,

and refining components

that deliver superb sonic

reproduction. Every part of

every component is

designed and built to

exacting specifications and

undergoes rigorous,

comprehensive testing

in the laboratories.

Research remains an

integral, driving force

behind all production.

Meyer strives for sound

quality that is predictable

and neutral over an

extended lifetime and

across an extended range.

PRELIMINARY

LD-2 SPECIFICATIONS

LD-2 – 04.088.004.01

Architecture

Audio Inputs

Audio Outputs

AC Power

Audio

Performance

Physical

Notes

–12 to +6 dB
–12 to +6 dB
160 Hz high-pass, –12 dB/octave, Q = 0.8
6 dB cut at 220 Hz, 0.6 octave bandwidth
Mute switches for Master, Mid-Hi, Mid-Bass/Aux, and Sub outputs
Toggles for Sub and Mid-Bass/Aux outputs

1 female XLR per channel
Differential balanced input circuit
10 kΩ differential (between pins 2 and 3)
Pin 1: chassis/earth ground; Pin 2: signal; Pin 3: signal
Common Mode: 425 kHz low-pass; Differential Mode: 142 kHz low-pass
> 80 dB (typically 90 dB); measured in the range 50 Hz – 1 kHz
(Variable intensity; monitored at the input for each channel)
–26 dBV (50 mVrms) pink noise or sinewave
–10 dBV (300 mVrms) pink noise or sinewave

Balanced, cross-coupled simulated transformer topology
10Ω balanced (between pins 2 and 3)
Pins 2 and 3 shunted to chassis via 500 pF capacitance

1 female XLR/channel
Pin 1: chassis/earth ground; Pin 2: signal; Pin 3: signal

1600 Ω Load: ±22.5 Vpk (+24 dBV, +26.2 dBu sinewave)
No Load: ±25.0 Vpk (+25 dBV, +27.2 dBu sinewave)
±70 mApk (10 Vrms into 200 Ω)
Drives > 100,000 pF (> 1000 ft cable) without instability or distortion

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

< ±0.2 dB 20 Hz – 20 kHz
DC to 60 kHz (–3dB)

< ±3° from pure 3 µsec delay (DC – 20 kHz)
> 120 dB
> –95 dBV A-weighted; > –90 dBV un-weighted
< 0.005% (typically 0.002%)
< ±0.15 dB at +6 dB gain; < ±0.25 dB at 0 dB gain
> 80 dB

–12 to +6 dB

Height: 1.75” (1 rack space); Width: 16.75”; Depth: 6.96”

13.5 lb (6.1 kg); shipping: 15 lb (6.8 kg)
Black 16-gauge steel chassis; 1/8” aluminum rack ears

1

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