Atlas Sound MG2500 User Manual

Atlas Sound MG2500

Sound Masking Generator

with 2-Channel DSP

and Page Input

Operation Manual

Atlas Sound, 1601 Jack McKay Blvd., Ennis, TX 75119 U.S.A. [phone] http:// www.AtlasSound.com

blank

May 2002

space unit. Noise & audio levels, plus two

TABLE OF CONTENTS

Front & Rear Panel Features
Setup
Logic Inputs
RS-232 Control
Specifications & Block Diagram
Warranty
Leveler FAQ’s

pg. 2

pgs. 3~11

pg. 12
pg. 13
pg. 14

pg.15

pg. 16

MG2500

INTRODUCTION

The Atlas Sound MG2500 Sound Masking Processor provides a digital pink­noise generator, a balanced line-level audio input, and a 2-channel DSP
processor, all in a single rack­channels of EQ, gain management, & delay, are adjusted via computer
software. Sixteen presets can be recalled via contact-closures, RS-232, or
other remote control options. The MG2500 carries a five-year warranty.

MG2500 features include:

♦ pink-noise & audio input, with 2-channel DSP processor
♦ noise generator spectral purity (±0.1dB @ 0Hz~20kHz)
♦ precision pink-noise filtering (-3dB per octave low-pass)
♦ generator repeat time of noise (200 minutes)
♦ combined 1/3-octave & parametric equalization per channel
♦ selectable high & low frequency shelving filters per channel
♦ HPF & LPF with variable frequency & slope per channel
♦ leveling, compression, limiting, & soft-gating per channel
♦ output delay, with distance/delay calculation, per channel
♦ two independent matrixes for channel-to-channel mixing
♦ variable noise, input, & output levels with software metering
♦ sixteen non-volatile memory presets store/recall settings
♦ balanced input & outputs on plug-in barrier strip connectors
♦ software for Windows

®

95/98/NT/2000/XP & cable included

♦ no manual controls on front panel, to prevent tampering
♦ remote control via RS-232 & programmable logic inputs
♦ incorporates AES recommended grounding practices
♦

marked and UL / C-UL listed power source

♦ covered by Atlas Sound’s five-year warranty

1

FRONT & REAR PANEL FEATURES

27V

~

50/60 Hz

serial port

12 watts

class 2 wiring

On Indicator: When power is applied to the MG2500, this red
LED will light indicating power to the unit is On. When power is
turned off, all current settings will be stored in non-volatile memory
and recalled when power is turned back on. NOTE: During setup

the MG2500 may instead be set to recall a special preset
whenever power is turned on (see Setup on pg. 10).

AC Power Cord: The power transformer provides 27 Volts AC to
the MG2500, and is detachable via a 5-pin DIN connector. The
MG2500
serviceable parts inside the unit). If the internal fuses blow, they
will attempt to re-set after a short period. However, this may be an
indication that the MG2500

Serial Port: This 9-pin Sub-D (male) connector provides an RS­232 Serial Port for remote control via computer or third-party
controllers (see RS-232 Control on pg. 13). The Serial Port has
the following pin assignments (left-to-right & top-to-bottom): Pin 1)
not used; Pin 2) Receive Data (RxD) input; Pin 3) Transmit
Data (TxD) output; Pin 4) Data Terminal Ready (DTR) output;
Pin 5) Ground; Pin 6) not used; Pi n 7 ) Request To Send (RTS)
output; Pin 8) not used; Pin 9) not used. The default baud rate
for the Serial Port is 38,400 (See RS-232 Control on pg. 13). Atlas
Sound MG2500 software and a serial cable are provided for
programming via Windows

3). NOTE: The Serial Port can also transmit commands received

via the Logic Inputs (see Setup on pg. 10).
Link Port: This 9-pin Sub-D (female) connector provides a Link

Port for RS-232 control of multiple ATLAS SOUND
(see RS-232 Control on pg. 13). The Link Port of one device
simply connects to the Serial Port of the next device (and so forth).

NOTE: All but the final MG2500 in a system should have the Link
Switch pressed in (see below). The Link Port has the following pin

assignments (right-to-left & top-to-bottom): Pin 1) not used; Pin

2) Transmit Data (TxD) output; Pin 3) Receive Data (RxD) input;
Pin 4) not used; Pin 5) Ground; Pi n 6) not used; Pin 7) not

used; Pin 8) not used; Pin 9) not used. NOTE: The Link Port
will also transmit commands received via the Logic Inputs (see
Setup on pg. 10).

link port link

logic inputs

output 1 inputoutput 2

has two internal ‘self-resetting’ fuses (there are no user

requires service.

®

95/98/NT/2000/XP (see Setup on pg.

®

MG2500’s

MG2500

Sound Masking Processor

on

Atlas Sound LP
1601 Jack
McKay Blvd
Ennis, TX 75119

MG2500

Sound Masking Processor

Made in U.S.A.

Link Switch: The Link Switch is used when connecting multiple
devices in a ‘Link Port to Serial Port’ configuration (see Link Port
above). From the factory, the Link Switch is released (out). When
connecting multiple devices, the Link Switch must be depressed
(in) on all devices except

the final device in the system (the device
with no Link Port connection). NOTE: The Link switch must
remain OUT when only a single device is being used.

Logic Inputs: This 25-pin Sub-D (female) connector provides
sixteen logic inputs for controlling the MG2500

via contact-closures

(see Logic Inputs on pg. 12). Logic Inputs are programmed using
the software and serial cable provided with the MG2500
Setup on pg. 10). NOTE: From the factory, Logic Inputs 1~16

have no pre-programmed function.

Outputs 1 & 2: These plug-in barrier strips provide the balanced
analog line-level Outputs from processor Channels 1 & 2. For
balanced output, wire high to (+), low to (-), and ground to (
unbalanced output, wire high to (+) and ground to (



). For



), leaving (-)
unconnected. Signal level will be reduced by 6dB when outputs
are unbalanced.

Input: This plug-in barrier strip provides the balanced analog line­level audio input. For balanced input, wire high to (+), low to (-),
and ground to (
ground to both (-) & (



). For unbalanced input, wire high to (+) and



). NOTE: The internal pink-noise generator
provides a second input. Input & noise may be assigned in any
combination to the two processing channels (see Setup on pg. 4).

(see

2

SETUP

MG2500
MG2500

parameters are all adjustable using the Windows
program includes several control screens, which are described on the following pages. Once the software is started (and Comm

Port Configuration is set), the control screens are accessed via the drop-down menus at the top of the opening screen. The Main
appears whenever an MG2500
the Main screen. Logic Definition

file is opened. Gain Matrix #1, Gain Manager, EQ, Gain Matrix #2, & Delay screens are then available from

& Configuration Options screens are also available from the Configure MG2500 menu. The File menu
provides functions such as save, open, download, etc. The Settings
menu arranges the active product screens. The Help
from the ‘Start’ menu, and enter A:\SETUP. System Requirements
(serial port required for ‘on-line’ operation).

®

95/98/NT/2000/XP software and serial cable provided with the unit. The

menu recalls the Comm Port Configuration screen. The Window

menu explains the available adjustments. To install MG2500 Software: Select ‘Run’

: Windows® 95/98/NT/2000/XP with 5MB of available hard disk space

screen

MAIN SCREEN

The Main Screen is used to adjust MG2500 input/output levels, to access the processing control screens, and to store/recall Presets 1~16.
Adjustments are made with the computer mouse (or keyboard). Input, Noise, Output 1, & Output 2 levels are adjusted by dragging the
corresponding ‘faders

’ up or down. These are the analog signal input & output circuits. ‘Meters’ are provided on each channel to display
input/output levels at specific points along the digital signal processing paths, and at the analog outputs. NOTE: For best performance,
adjust levels so the meters show occasional peaks in the yellow area, but never to the top (red). Output 1 Mute & Output 2 Mute
the respective output signal on/off, as well as indicate the output muting status. Logic Inputs
Logic Inputs are turned on via external remote control (see Logic Inputs on pg. 12). Preset
non-volatile memory. Presets must first be created & stored by the user (no factory presets). The Store

indicators will light whenever the respective

buttons recall the corresponding presets from

button opens a menu for storing

will toggle

current settings in any of the Presets 1~16. Presets may be stored and recalled (in total or in part) via remote control (see Logic Input
Definitions screen on pg. 10). The title bar across the top of the Main screen will indicate the Device #, the custom Device Name, and the
model of product being controlled. MG2500 software can operate ‘off-line’ (with no product connected) by opening a ‘new’ file for the
desired product. The Device # for ‘off-line’ files is assigned sequentially as a negative number.

3

SETUP

GAIN MATRIX #1 SCREEN

The Gain Matrix #1 screen provides a channel-to-channel (2x2) mix matrix, which can be used to adjust the amount of Input & Noise signal
being routed to each of the processing channels (Output 1 & Output 2). From the factory, Input 1 is routed to Output 1 only, and Noise is
routed to Output 2 only, providing two independent signal paths. Levels are adjusted by dragging the corresponding ‘faders

’ are provided on each channel to display input/output levels at Gain Matrix #1. NOTE: For best performance, adjust levels so the

‘Meters

meters show occasional peaks in the yellow area, but never to the top (red). Invert
be reversed (180°).

The MG2500 has two basic applications which utilize Gain Matrix #1

1) Input 1 can be routed to Output 1 and Noise can be routed to Output 2. Each channel of processing is dedicated to either Input 1 or
Noise signal. Switching between Input 1 & Noise signals (to either Output) is then accomplished via Gain Matrix #2 presets (see Gain
Matrix #2 screen on pg. 8). This is effective when only a single output (zone), or two outputs (zones) with independent delay, are required.

2) Gain Matrix #1 presets can be used to switch between Input 1 or Noise signal being routed to either Output. Each channel of
processing is dedicated to a specific Output (zone), via Gain Matrix #2. Separate EQ presets for Input 1 & Noise signals, as they appear at
each output (zone), can also be used. This is effective when two outputs (zones), each with dedicated processing, are required.

Of course, the MG2500 can simply be configured for processing Noise (or Input 1) signal only, at both Outputs.

:

allows the phase of each corresponding signal path to

’ up or down.

4

SETUP

GAIN MANAGER SCREEN

The Gain Manager screen is used to adjust Leveler, Compressor, Limiter & Soft Gate settings for each of the processing channels (Output
1 & Output 2). Threshold
controls determine the amount and type of gain processing to be applied to the signals. The Leveler
level. If the average signal level increases, the Leveler will reduce gain to compensate. If the average signal level decreases, the Leveler
will increase gain to compensate. The Compressor
automatically varies in ratio from 1.1:1 on signals just slightly above Threshold, to more than 10:1 at full compression. The Compressor
responds to average & peak levels, working with the Leveler to maintain a constant output level. The Limiter
signal level by providing ‘hard’ limiting, which establishes an absolute ceiling level. The Limiter provides protection against clipping
distortion, and the chance of amplifier overload or speaker damage, due to sudden transients. From the factory, the default Threshold
settings will provide approximately 6dB of gain reduction on input signals of nominal level. Bypass
Compressor, or Limiter functions for that Channel, without changing the actual settings. Soft Gate Bypass
circuit for that Channel, which reduces gain 2dB for each 1dB that signal falls below threshold (-30dBu). The Soft Gate gracefully
attenuates background/ambient noise during periods of silence. Bypass GM
functions for that Channel, without changing the actual settings. ‘Meters
well as the amount of gain reduction, at the Gain Manager section. NOTE: The Gain Manager provides gain reduction even on input

signals of nominal level. Therefore, all subsequent meters will indicate the resultant lower levels. CAUTION: The Gain Manager can
increase gain for lower level signals. Therefore, after all system settings have been adjusted, temporarily bypass the Gain Manager as a
test of system feedback stability. If acoustic feedback occurs, reduce the system amplifier levels or use the MG2500 parametric equalizer
to eliminate feedback nodes, before re-enabling the Gain Manager.

adjusts the signal level at which the Leveler, Compressor, & Limiter functions are triggered. Therefore, these

controls short-term peaks in signal level by providing ‘soft-knee’ compression, which

’ are provided on each channel to display input/output levels, as

defeats all Leveler, Compressor, Limiter, & Soft Gate

controls the long-term average signal

controls short-term peaks in

defeats the individual Leveler,

defeats a downward expander

5