Dolby Laboratories 430 User Manual

430 SERIES

BACKGROUND NOISE

SUPPRESSOR SYSTEM

Installation and

Operating Instructions

MAIN

INSTALLATION AND

OPERATING INSTRUCTIONS

FOR

430 SERIES BACKGROUND

NOISE SUPPRESSOR SYSTEM

Dolby Laboratories Incorporated

U.S.A. 100 Potrero Avenue, San Francisco, CA 94103

Tel: [phone]; Fax: [phone]

U.K. Wootton Bassett, Wiltshire, SN4 8QJ, England

Tel: [phone]; Fax: [phone]; Telex: 44849

WARRANTY INFORMATION: warranty on the product covered by this manual is subject to the limitations and disclaimers set forth in the

warranty disclaimer originally shipped with the product and also printed on the back of the invoice.

Dolby and the double-D are registered trademarks of Dolby Laboratories Licensing Corporation.

©1994 Dolby Laboratories

ISSUE 3

S94/9359/10081

Part No. 91262

MAIN

DOLBY 430

DOLBY 430

D

OLBY

430 B

ACKGROUND

N

OISE

S

UPRESSOR

BACKGROUND NOISE SUPPRESSOR

BACKGROUND NOISE SUPPRESSOR

T

he Dolby 430 Series is a background

noise suppressor system for reducing the

broadband noises such as wind or traffic rum-

ble that often mar location recordings. Many

mixers in film and television postproduction

already rely on Dolby Laboratories’

Cat. No.43, a background noise suppression

unit based on a modified version of Dolby

A-type noise reduction. The 430 Series takes

this concept further by using a modified ver-

sion of Dolby SR’s patented combination of

fixed and sliding bands to give more stable

signal handling and a significantly reduced

chance of audible side effects.

While superior in performance to the

Cat. No.43, the 430 Series uses fewer con-

trols. Low- and high-frequency faders adjust

the amount of noise suppression above and

below dominant mid-frequency signals such

as dialogue. A pull-to-engage control permits

varying the preset operating level for record-

ings at unusually high or low levels (overall

gain of the unit remains fixed).

The 430 Series is a modular system pro-

viding from one to six channels of background

noise suppression. A single control unit pro-

vides power and control signals for up to three

single-rackspace frames, each with one or two

channels of processing. All operating controls

are mounted in a remote control module

which may be located up to 15 meters (50

feet) from the control unit. These remote con-

trols have been specifically designed for easy

console mounting. Alternatively, a housing is

available to allow for standalone operation.

100 Potrero Avenue

San Francisco, CA 94103-4813

Telephone [phone]

Fax [phone]

[e-mail]

Wootton Bassett

Wiltshire SN4 8QJ, England

Telephone [phone]

Fax [phone]

[e-mail]

www.dolby.com

MAIN

Signal Processing

Independent low- and high-frequency stages with

maximum noise suppression of approximately

16 and 18 dB, respectively

Signal Connection

3-pin XLR connectors for audio; 34-way ribbon

connector links processing module frames to power

supply/control unit; one 15-way D-connector con-

nects remote controls for all channels

Operating Controls

Operating controls for each channel of processing

are mounted on Cat. No.429 Remote Control

module

Level: rotary control varies signal level in processing

circuitry over a ±6 dB range without changing

overall gain of unit

In/out: push-button with LED indicator switches

processing in and out of circuit

HF & LF: fader controls set attenuation of

unwanted low-level signals

Signal Levels

Nominal input and output level +4 dBr

1

Input Circuits

Electronically balanced, 20 kΩ input impedance,

substantially resistive; common mode rejection

better than 55 dB, 50 Hz to 10 kHz; maximum

input level +27 dBr balanced, +21 dBr unbalanced

Output Circuits

Electronically balanced, approximately 20Ω

output impedance; output balance better than 1 dB

into a symmetrical 600Ω load; output float

2

better than –40 dB, 50 Hz to 1 kHz; maximum

signal level into 600Ω or greater: +26 dBr balanced,

+20 dBr unbalanced; either leg of the output can be

grounded for unbalanced operation with no change

in level

Frequency Response

±1 dB 20 Hz to 20 kHz with LF and HF controls

set to 0

Crosstalk

Channel to channel within a single frame: better than

–94 dB 20 Hz to 20 kHz

Power Line Input

User-selected voltage ranges (50–60 Hz, single-

phase); nominally 100 V (85–110 V), 110 V

(102–132 V), 220 V (187–242 V),

240 V (204–264 V)

Size

Processor and power supply/control units: 44 × 483

mm (standard 1.75 × 19 inches rack mounting );

maximum projection behind mounting surface:

330 mm (13 inches) including connectors; remote

control panels: 150 mm x 39.5 mm (5.91 × 1.56

inches ); maximum projection behind control

surface: 100 mm (3.94 inches) including connec-

tors; may be console-mounted, mounting holes on

142.9 mm (5.63 inches) centers.

Weight

Model Weights (including remotes): 430-S1, 8 kg

(17.5 lb); 430-S2, 9 kg (19.6 lb); 430-S3,12.9 kg

(28.3 lb); 430-S4, 14 kg (30.6 lb); 430-S5,

17.8 kg (39.2 lb); 430-S6, 18.8 kg (41.4 lb)

Accessories

430SU1: single-channel upgrade package with

one channel module, one remote control and rack

mounting frame with blanking plate.

430SU2: two-channel upgrade package with two

channel modules, two remote controls and rack

mounting frame.

430SK1: single-channel upgrade package with one

processing module and one remote control only (no

frame included).

Cat. No. 428: remote housing for up to three

Cat. No. 429 remote controls.

Regulatory Notices

US: This unit is UL listed.

Europe: The 230 Volt unit complies with the

requirements of Low Voltage Directive 73/23/EEC.

Warranty

One-year limited, parts and labor

1

0 dBr = 0.775 mV

2

Output float is the level across a balanced load relative to an interfering

signal injected at one end of the load

Specifications subject to change without notice.

Dolby and the double-D symbol are trademarks of Dolby Laboratories.

© 2000 Dolby Laboratories, Inc.S00/00000

430 S

PECIFICATIONS

DISCLAIMER OF WARRANTIES:

Equipment manufactured by Dolby

Laboratories is warranted against

defects in materials and workmanship

for a period of one year from the date of

purchase. There are no other express

or implied warranties and no warranty

of merchantability or fitness for a partic-

ular purpose.

LIMITATION OF LIABILITY: It is

understood and agreed that Dolby

Laboratories’ liability whether in con-

tract, in tort,under any warranty, in neg-

ligence or otherwise shall not exceed the

cost of repair or replacement of the

defective components and under no cir-

cumstances shall Dolby Laboratories be

liable for incidental, special,direct, indi-

rect or consequential damages (includ-

ing but not limited to damage to soft-

ware or recorded audio or visual mater-

ial), or loss of use,revenue or profit even

if Dolby Laboratories or its agents have

been advised, orally or in writing, of the

possibility of such damages.

DOLBY NOISE REDUCTION

Dolby noise reduction is a family of

signal processes that reduce the noise

inherent in analog recording media,

without affecting the sound being

recorded. While they differ in perfor-

mance and details of operation, all

Dolby NR systems are complementary

processes that first encode the music

when it is recorded, then decode it

when it is played back. They also treat

soft signals separately from loud ones,

and vary the NR action with frequency

to avoid the side effects typical of other

systems.

Dolby A-type noise reduction, intro-

duced in 1965, was originally intended

for use by professional recording studios

to make quieter master tape recordings.

In the early 1970s its use was extended

to film studios and motion picture

release prints to make films sound

better.

Dolby SR (spectral recording), intro-

duced in 1986, was designed not only to

provide more noise reduction than

A-type, but also to enable analog master

recordings that equal or surpass 16-bit

digital recordings with respect to overall

dynamic range. Today, analog with

Dolby SR is still a preferred format for

some musicians, producers, and record-

ing and mastering facilities, and is the

standard format for the analog sound-

tracks of virtually all feature films.

MAIN

i

TABLE OF CONTENTS

INTRODUCTION

SECTION 1 UNIT CONFIGURATIONS

1.1 The Model 430 System .................................................................................................. 1-1

1.2 Accessories .................................................................................................................... 1-1

SECTION 2 OPERATION

2.1 Controls .......................................................................................................................... 2-1

2.2 Practical Operation ......................................................................................................... 2-2

2.3 Console Signal Path Insertion Guide ............................................................................. 2-3

SECTION 3 INSTALLATION

3.1 Control unit and Suppressor Frames ............................................................................. 3-1

3.2 Console Mounting of Remotes ....................................................................................... 3-3

3.3 Channel Number Assignment ........................................................................................ 3-3

3.4 Panel Cut-Out Templates for Cat. No. 428 Remotes ..................................................... 3-4

3.5 Regulatory Notices ......................................................................................................... 3-5

SECTION 4 THEORY OF OPERATION

SECTION 5 SCHEMATIC DIAGRAMS

APPENDIX

A1 Plugging Precautions ..................................................................................................... A-1

MAIN

ii

INTRODUCTION

The Model 430 Series is a playback-only noise reduction system intended primarily to reduce unwanted

ambient noise from location recordings. Typically, this noise is generated by broadband sources such as

generators, wind, or traffic.

The Model 430 Series is a second-generation design, following from the Cat. No. 43 unit—a successful

background noise suppressor in widespread use in post-production facilities throughout the world. The

Model 430 unit offers several benefits over the earlier design, including improved ease of operation, and a

reduced risk of side effects.

The earlier design was based on Dolby A-type noise reduction techniques, and incorporated user control of

each of its four fixed bands to accomplish playback noise reduction. The Model 430 design is based on

Dolby spectral recording techniques, with a multiple combination of low- and high-frequency fixed and

sliding bands. Basic user controls have been reduced to two, controlling the amount of playback noise

reduction above and below the dominant signal of interest, typically above and below mid-frequency dialog

components. The use of Dolby SR fixed and sliding bands in combination results in much more stable

signal handling with a significantly reduced chance of audible background signal pumping. Nevertheless,

the user is cautioned that, as with all non-complementary playback-only noise reduction devices, excessive

use and certain signal combinations can lead to audible side-effects.

The Model 430 Series is not intended for suppression of spot-tone signals, such as camera noise or power

line hum interference. Noise sources such as this may well be better treated with a dip filter.

In typical applications, the Model 430 Series unit is placed in the signal path of a sound mixing console

where nominal line levels are present. It is intended to operate at a level around +4 dBr (Ref: 0.775 Vrms).

MAIN

1-1

SECTION 1

UNIT CONFIGURATIONS

1.1 The Model 430 System

The Model 430 is a modular system which has a control unit containing the power supply and

microprocessor. The control unit links to one or more enclosures each of which contains one or two noise

suppression modules and also links to one or more remote control modules. The 40mm wide format of the

remote control modules makes them easily mountable in spare sections of many mixing consoles.

Alternatively, they may be mounted in an optional housing which can mount up to three remote control

modules.

Linking of the units is accomplished by a short ribbon cable bus between the control unit and the suppressor

module enclosures and a 15-meter shielded cable between the control unit and remote control modules.

Where the remotes are console mounted, there are 15-way ribbon cable assemblies which allow flexible

use of the spare space in the console.

The figure below shows a complete 6-channel system along with the various component part numbers.

A1F4356B REV2

430 Series Noise Suppressor Module

Cat. No. 413

Dolby

Normal

Bypass

5

0

1

2

3

4

Dolby

430

Series

Remote

Level

Pull to

Clip

Adjust

LF

HF

in

Bypass

Normal

Dolby

Cat. No. 413

430 Series Noise Suppressor Module

430 Series Control Unit

6

5

4

3

2

1

Channels

Error

Remote

Error

Channel

Dolby

430 Series Noise Suppressor Module

Cat. No. 413

Dolby

Normal

Bypass

Bypass

Normal

Dolby

Cat. No. 413

430 Series Noise Suppressor Module

430 Series Noise Suppressor Module

Cat. No. 413

Dolby

Normal

Bypass

Bypass

Normal

Dolby

Cat. No. 413

430 Series Noise Suppressor Module

in

HF

LF

Adjust

Clip

Pull to

Level

Remote

Series

430

Dolby

4

3

2

1

0

5

in

HF

LF

Adjust

Clip

Pull to

Level

Remote

Series

430

Dolby

4

3

2

1

0

5

in

HF

LF

Adjust

Clip

Pull to

Level

Remote

Series

430

Dolby

4

3

2

1

0

5

in

HF

LF

Adjust

Clip

Pull to

Level

Remote

Series

430

Dolby

4

3

2

1

0

5

in

HF

LF

Adjust

Clip

Pull to

Level

Remote

Series

430

Dolby

4

3

2

1

0

5

430PS POWER SUPPLY AND CONTROL UNIT

430SU2 2 CHANNEL SUPPRESSOR UNIT

430SU2 2 CHANNEL SUPPRESSOR UNIT

430SU2 2 CHANNEL SUPPRESSOR UNIT

PART NO. 83093

PART NO. 83128

430 SERIES

430 SERIES

6 CHANNEL

15 METER

REMOTE CABLE

FLAT CABLE

PART NO. 83131

PART NO.83127

430 SERIES

3 REMOTES CABLE

REMOTE CONTROLS

CAT. NO. 429

430 SERIES

REMOTE EXTENSION CABLE

(ALSO USED FOR 4 REMOTES)

430 SERIES

PART NO. 83121

LINK

CHASSIS GROUND

MAIN