Sonifex Redbox RB-DMX4 Instruction Manual

Redbox RB-DMX4
4 x 4 Channel Digital Audio
Mixer/Router
User Handbook

bRedbox RB-DMX4 User Handbook
This handbook is for use with the following product:
Redbox RB-DMX4 4 x 4 Channel Digital Audio Mixer/Router
©Sonifex Ltd, 2009
All Rights Reserved
Revision 1.00, October 2009
Sonifex Ltd, 61, Station Road, Irthlingborough,
Northants, NN9 5QE, England.
Tel: [phone]
Fax: [phone]
Email: [email protected].uk
Website: http://www.sonifex.co.uk
Information in this document is subject to change without notice and does not represent a commitment on the part of
the vendor. Sonifex Ltd shall not be liable for any loss or damage whatsoever arising from the use of information or any
error contained in this manual.
No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical,
including photocopying, recording, information storage and retrieval systems, for any purpose other than the purchaser’s
personal use, without the express written permission of Sonifex Ltd. Unless otherwise noted, all names of companies,
products and persons contained herein are part of a completely ctitious adaptation and are designed solely to
document the use of Sonifex product.
RB-DMX4 USER HANDBOOK
RB-DMX4 USER HANDBOOK

Redbox RB-DMX4 User Handbook c
CONTENTS
CONTENTS
s
Warranty i
Warranty and Liability i
Unpacking the RB-DMX4 iii
Returning the Warranty Card iii
Safety Information iv
Safety of Mains Operated Equipment iv
Voltage Setting Checks iv
Fuse Rating iv
Power Cable and Connection iv
Ordering the Correct Mains Lead v
Installation Information vi
Atmosphere vi
Electromagnetic Radiation vi
Fitting Redboxes vi
Installing the Optional Video Sync Boards vi
Opening the RB-DMX4 vi
WEEE & RoHS Directives - Sonifex Statement viii
RB-DMX4 4 x 4 Channel Digital Audio Mixer/Router 1
Introduction 1
Master Mode 1
Auto Sync Mode 1
Auto Lock Mode 2
Slave Mode 2
Front Panel Controls and Indicators 3
Output Mix Matrix Selection Using The Front Panel DIPSwitches 3
INPUT 1 & 2 Source Select Button, Indicators & Input Presence LEDS 3
INPUT 3 & 4 Source Select Button, Indicators & Input Presence LEDS 4
INPUT GAIN Pots 4
MONITOR Button & Output Presence LEDs 4
MONITOR Button Modes 4
Display Mode 4
Monitor Output Select Mode 5
Output Gain Mode 5
SERIAL LED Indicator 5
Headphone Output 5
LEVEL Control 5
Reset Button 5
Rear Panel DIPSwitch Controls 6
Master Mode Sample Rate Selection (DIPSwitches 1-3) 6
Synchronisation Source Selection (DIPSwitches 4-6) 6
Synchronisation Mode Selection (DIPSwitches 7-8) 6
Stereo/Mono Operation of Input Gain and Monitor Select (DIPSwitch 9) 7
Monitor Attenuation (DIPSwitch 10) 7
Serial Mode (DIPSwitch 11) 7
Boot Mode (DIPSwitch 12) 7
Applications of Use 8
Stereo Mix of Two Stereo Digital Inputs 8
Mono Mix of Four Input Sources to Create your Own Stereo Output 8
One to Four Mono Distribution/ Creating Dual Mono Outputs 8
Two to Four Mono Distribution Or Creating Dual Mono Outputs 8
Four Channel Sample Rate Converter 8
Rear Panel Connectors 9
AES/EBU Outputs 9
S/PDIF Outputs 9
Optical Outputs 9
AES/EBU Inputs 9
S/PDIF Inputs 9

dRedbox RB-DMX4 User Handbook
CONTENTS & FIGURES
CONTENTS & FIGURES
Figures
Fig A: Packing List iii
Fig B: Power Connections iv
Fig C: Mains Lead Table v
Fig D: RB-RK3 Large Redbox Rear Rack-mount Kit vi
Fig E: RB-DMX4 Optional Video Sync Installation vii
Fig 1-1: RB-DMX4 Front Panel 1
Fig 1-2: RB-DMX4 System Block Diagram 2
Fig 2-1: RB-DMX4 Front Panel Controls and Indicators 3
Fig 2-2: RB-DMX4 Front Panel DIPSwitches 3
Fig 2-3: RB-DMX4 INPUT 1 & 2 Select Button 3
Fig 2-4: RB-DMX4 INPUT Gain Pots 4
Fig 2-5: RB-DMX4 MONITOR Button 4
Fig 2-6: RB-DMX4 Serial Control Indicator LED 5
Fig 2-7: RB-DMX4 Headphone Output & Level Control 5
Fig 3-1: RB-DMX4 Rear Panel DIPSwitch Block 6
Fig 5-1: RB-DMX4 Rear Panel 9
Fig 6-1: Serial Port Default Settings 11
Fig 7-1: Status Page 16
Fig 7-2: Control Page 17
Fig 7-3: Miscellaneous Page 18
Contents (Continued)...
Optical Inputs 9
AES/EBU Sync Input 10
Word Clock Input 10
Video Sync Input 10
Serial RS232 Connector 10
Remotes Connector 10
Serial Port Control 11
Serial Interface Commands and Responses 11
Error Messages 15
SCi for RB-DMX4 16
Status Page 16
Control Page 17
1. Select Input Sources 17
2. Select Synchronisation Options 17
3. Select Mix Matrix 18
4. Select Special Options 18
Miscellaneous Page 18
Updating The Firmware 19
Technical Specication For RB-DMX4 20

Redbox RB-DMX4 User Handbook i
Warranty
Warranty and Liability
Important: the purchaser is advised to read this clause
The Company agrees to repair or (at its discretion) replace Goods which are found toa.
be defective (fair wear and tear excepted) and which are returned to the Company
within 12 months of the date of despatch provided that each of the following
are satised:
notication of any defect is given to the Company immediately upon its becomingi.
apparent to the Purchaser;
the Goods have only been operated under normal operating conditions and haveii.
only been subject to normal use (and in particular the Goods must have been
correctly connected and must not have been subject to high voltage or to ionising
radiation and must not have been used contrary to the Company’s technical
recommendations);
the Goods are returned to the Company’s premises at the Purchaser’s expense;iii.
any Goods or parts of Goods replaced shall become the property ofiv.
the Company;
no work whatsoever (other than normal and proper maintenance) has beenv.
carried out to the Goods or any part of the Goods without the Company’s prior
written consent;
the defect has not arisen from a design made, furnished or specied byvi.
the Purchaser;
the Goods have been assembled or incorporated into other goods only invii.
accordance with any instructions issued by the Company;
the defect has not arisen from a design modied by the Purchaser;viii.
the defect has not arisen from an item manufactured by a person other thanix.
the Company.
In respect of any item manufactured by a person other than the Company, the Purchaser
shall only be entitled to the benet of any warranty or guarantee provided by such
manufacturer to the Company.
In respect of computer software supplied by the Company the Company does notb.
warrant that the use of the software will be uninterrupted or error free.
WARRANTY
WARRANTY

ii Redbox RB-DMX4 User Handbook
The Company accepts liability:c.
for death or personal injury to the extent that it results from the negligence of thei.
Company, its employees (whilst in the course of their employment) or its agents
(in the course of the agency);
for any breach by the Company of any statutory undertaking as to title, quietii.
possession and freedom from encumbrance.
Subject to conditions (a) and (c) from the time of despatch of the Goods from thed.
Company’s premises the Purchaser shall be responsible for any defect in the Goods
or loss, damage, nuisance or interference whatsoever consequential economic or
otherwise or wastage of material resulting from or caused by or to the Goods. In
particular the Company shall not be liable for any loss of prots or other economic
losses. The Company accordingly excludes all liability for the same.
At the request and expense of the Purchaser the Company will test the Goods toe.
ascertain performance levels and provide a report of the results of that test. The report
will be accurate at the time of the test, to the best of the belief and knowledge of the
Company, and the Company accepts no liability in respect of its accuracy beyond that
set out in Condition (a).
Subject to Condition (e) no representation, condition, warranty or other term, expressf.
or implied (by statute or otherwise) is given by the Company that the Goods are of
any particular quality or standard or will enable the Purchaser to attain any particular
performance or result, or will be suitable for any particular purpose or use under
specic conditions or will provide any particular capacity, notwithstanding that the
requirement for such performance, result or capacity or that such particular purpose or
conditions may have been known (or ought to have been known) to the Company, its
employees or agents.
g. To the extent that the Company is held legally liable to the Purchaser for anyi.
single breach of contract, tort, representation or other act or default, the
Company’s liability for the same shall not exceed the Price of the Goods.
The restriction of liability in Condition (g)(i) shall not apply to any liability acceptedii.
by the Seller in Condition (c).
Where the Goods are sold under a consumer transaction (as dened by theiii.
Consumer Transactions (Restrictions on Statements) Order 1976) the statutory
rights of the Purchaser are not aected by these Conditions of Sale.
WARRANTY
WARRANTY

Redbox RB-DMX4 User Handbook iii
Unpacking the RB-DMX4
The RB-DMX4 is shipped with the following equipment. Please check your packaging
to ensure that you have all of the items below. If anything is missing, please contact the
supplier of your equipment immediately.
Item Quantity RB-DMX4
RB-DMX4 1
IEC Mains lead tted with moulded mains plug 1
Handbook and warranty card 1
Fig A: Packing List
Each RB-DMX4 is shipped in protective packaging and should be inspected for damage
before use. Where an item is found to have transit damage, notify the carrier immediately
with all the relevant details of the shipment. Packing materials should be kept for
inspection and also for if the product needs to be returned.
Returning the Warranty Card
In order to register the date of purchase so that we can keep you informed of any design
improvements or modications, it is important to complete the warranty registration
document that is enclosed and return it to Sonifex Ltd in the UK.
For your own records you should write down the serial number (which can be found on the
rear of the RB-DMX4.
Serial Number ………………………………………
WARRANTY
WARRANTY

iv Redbox RB-DMX4 User Handbook
Safety Information
Safety of Mains Operated Equipment
This equipment has been designed to meet the safety regulations currently
advised in the country of purchase and it conforms to the safety regulations
specied by use of the CE Mark.
Warning : There are no user serviceable parts inside the equipment. If you should ever
need to look inside the unit, always disconnect the mains supply before removing the
equipment covers.
Voltage Setting Checks
Ensure that the machine operating voltage is correct for your mains power supply by
checking the box in which your Redbox was supplied. The voltage is shown on the box
label. The available voltage settings are 115V, or 230V. Please note that all Redboxes are
either switchable between 115V and 230V, or have a universal power supply.
Fuse Rating
The RB-DMX4 is supplied with a single fuse in the live conducting path of the mains
power input. For reasons of safety it is important that the correct rating and type of fuse is
used. Incorrectly rated fuses could present a possible re hazard, under equipment fault
conditions. The fuse rating for the RB-DMX4 is:
230 or 115 V operation - 2A 5 x 20mm SB
The active fuse is tted on the outside rear panel of the unit.
Power Cable and Connection
An IEC power connector is supplied with the RB-DMX4 which has a moulded plug attached
– this is a legal requirement. If no moulded plug has been supplied with your RB-DMX4,
please contact your supplier, because an IEC connector is always supplied from the Sonifex
factory.
If for any reason, you need to use the RB-DMX4 with a dierent power cable, you should
use the following wiring guidelines.
Wire Colour Connection
Green, or green and yellow Earth (E)
Blue, or Black Neutral (N)
Brown, or Red Live (L)
Fig B: Power Connections
Connect the equipment in accordance with the connection details and before applying
power to the unit, check that the machine has the correct operating voltage for your mains
power supply.
Important Note : The terminal marked on the rear panel must be earthed.
SAFETY INFORMATION
SAFETY INFORMATION

Redbox RB-DMX4 User Handbook v
Ordering the Correct Mains Lead
When ordering a Redbox from Sonifex, it is helpful if you can specify your required
operating voltage and mains lead. After the product code add:
UK, for 230V, UK 3 pin to IEC lead
EC, for 230V, European Schuko 2 pin to IEC lead
US, for 115V, 3 pin to IEC lead
AU for 230V, Australasian 3 pin to IEC lead
Fig C: Mains Lead Table
E.g. order RB-DMX4 UK for a UK IEC lead to be supplied.
SAFETY INFORMATION
SAFETY INFORMATION

vi Redbox RB-DMX4 User Handbook
INSTALLATION INFORMATION
INSTALLATION INFORMATION
Installation Information
Atmosphere
The units should be installed in an area that is not subject to excessive temperature
variation (<0°C, >50°C), moisture, dust or vibration.
Electromagnetic Radiation
The cover is connected to earth by means of the xing screws. It is essential to maintain
this earth ground connection to ensure a safe operating environment and provide
electromagnetic shielding.
Fitting Redboxes
Redboxes can be xed to the underside of a mixing desk, or other surfaces using 4.2mm
holes in the sides and xed with 2 x M4 screws or 2 x No. 6 countersink wood screws.
They can also be rack-mounted, with either the front, or rear of the Redbox positioned at
the front of the rack:
Rear Mounting The RB-DMX4: The RB-RK3 1U rear panel rack kit can be used for large
Redboxes such as the RB-DMX4.
Fig D: RB-RK3 Large Redbox Rear Rack-mount Kit
Note: When tting the rear-mounting rack-kits, a notch has been left on the inside of
the right-hand rack-piece for the mains cable to pass through. Make sure that the mains
cable has been put through the notch before attaching the right hand rack-piece.
Installing the Optional Video Sync Boards
There are 2 optional video sync boards which can be used to synchronise the outputs of
the RB-DMX4 to a 48kHz sample rate from an analogue or digital video signal:
RB-SYA - The Analogue video sync board will accept a composite signal of NTSC (525), PAL
(625) & SECAM (625) signals covered by SMPTE-170-M (NTSC) and ITU-R BT.470-6 (PAL &
SECAM).
RB-SYD - The Digital video sync board will accept 270Mbps SD-SDI and HD-SDI signals
covered by SMPTE-259-M-C (SD) and SMPTE-292M (HD).
Opening the RB-DMX4
Warning: The power must be switched o at the supply or the power lead must be
disconnected before attempting to open the unit. Removal of the cover can expose
dangerous voltages.

Redbox RB-DMX4 User Handbook vii
INSTALLATION INFORMATION
INSTALLATION INFORMATION
1. Remove the 4 screws in the corners of the rear panel.
2. Remove the 4 screws on the top and bottom panels which hold the rear panel in
place (2 on the top and 2 on the bottom).
3. Remove the screw in the centre of the front panel.
4. Slide the rear panel and main PCB backwards out of the metal chassis giving you
internal access.
5. Remove the rubber grommet/bung on the rear panel which covers the hole for the
video sync connector.
6. Remove the 2 screws from the bottom of the sync card pillars and, making sure to
keep the plastic washers in place at the bottom of the pillars, t the 20 way pin
header into the 20 way connector on the RB-DMX4 motherboard.
7. Underneath the board, insert the 2 screws to x the board in place.
To put the unit back together, slide the PCB back into the chassis and ret the screws in
reverse order.
The video synchronisation is chosen using the front panel DIPSwitches (see page 5).
Follow these instructions to t either of the sync boards.
Reset
Sync Card
Pillar Mount
Power
Plug
Fuse
Case
Remote
Connector
Dipswitches
Sync Card
Pillar Mount
Word Clock
AES/EBU
Sync
Input
Fig E: RB-DMX4 Optional Video Sync Installation

viii Redbox RB-DMX4 User Handbook
WEEE & RoHS Directives - Sonifex Statement
The Waste Electrical and Electronic Equipment (WEEE) Directive was agreed on
13 February 2003, along with the related Directive 2002/95/EC on Restrictions
of the use of certain Hazardous Substances in electrical and electronic
equipment (RoHS).
The Waste Electrical and Electronic Equipment Directive (WEEE) aims to minimise the
impacts of electrical and electronic equipment on the environment during their life times
and when they become waste. It applies to a huge spectrum of products. It encourages
and sets criteria for the collection, treatment, recycling and recovery of waste electrical and
electronic equipment. All products manufactured by Sonifex Ltd have the WEEE directive
label placed on the case. It gives a contact for individuals who are unsure about the correct
procedure when the product has reached its “end of use”.
Sonifex Ltd will be happy to give you information about local organisations that can
reprocess the products, or alternatively all products that have reached “end of use”can be
returned to Sonifex and will be reprocessed correctly free of charge.
Sonifex Ltd has phased out the use of certain hazardous substances identied in the
European Union’s Restriction of Hazardous Substances (RoHS) directive. The RoHS
directive limits the use of certain hazardous substances currently used in EEE manufacture,
including lead, mercury, cadmium, hexavalent chromium, and halide-containing
compounds PBB (polybrominated biphenyl) and PBDE (polybrominated diphenyl ether).
Elimination of these substances will result in more environmentally friendly recycling
of electronic equipment. For the products which Sonifex manufacture, the main area
where products were aected was in the use of lead for manufacturing and assembling
electronics circuit boards.
Sonifex Ltd practices lead-free (LF) manufacturing processes. LF solder is used on the
surface-mount PCB manufacturing processes and for hand soldering. The printed circuit
boards (PCBs) used are either gold plated, or immersion tin plated, both of which use no
lead. Historically the PCBs were hot air solder levelled (HASL) PCBs which used tin/lead
based solder.
The manufacturing processes include the assembly of purchased components from
various sources. Product is oered as RoHS compliant, or LF, only after sucient evidence
is received from the component manufacturers that their components are RoHS compliant.
Sonifex Ltd relies solely on the distributor, or manufacturer, of the components for
identication of RoHS compliance. Thus whilst every eort is made to ensure compliance,
Sonifex Ltd makes no warranty, or certication, or declaration of compliance concerning
said components.
Sonifex Ltd denes“Lead Free” as pertaining to any product, which has been manufactured
by Sonifex Ltd using components which have been declared by the manufacturers as
“Lead Free”. All statements by Sonifex Ltd of RoHS compliance are based on component
manufacturer documentation.
WEEE & ROHS
WEEE & ROHS

Redbox RB-DMX4 User Handbook 1
INTRODUCTION
INTRODUCTION 1
RB-DMX4 4 x 4 Channel Digital Audio Mixer/Router
Introduction
Fig 1-1: RB-DMX4 Front Panel
The RB-DMX4 is a digital mixer capable of mixing or routing 4 mono input channels into 4
mono outputs, or 2 stereo inputs into 2 stereo outputs. The inputs are sample rate converted
to allow sources of dierent sample rates to be mixed. The exible Mix Matrix allows for a
wide variety of mixing options and creativity, using 4 blocks of 4 way DIPswitches to select
which inputs are mixed or routed to which outputs.
The RB-DMX4 has 4 x digital mono audio inputs, each one selectable in pairs via front panel
INPUTS 1 & 2 and INPUTS 3 & 4 push buttons, from either AES/EBU balanced XLRs, S/PDIF
unbalanced phonos or TOSlink unbalanced optical inputs. Sample rate converters on each
input mean that sources of dierent sample rates can be used with the output sample rate
being dened independently. The colour of the INPUTS 1 & 2 and INPUTS 3 & 4 push-buttons
indicate whether the input source is synchronised (no colour) or not (ashing green and red).
Each input has a trim pot, which can be used to attenuate the input signal. This allows for
a perfect mix of channels at dierent audio levels. Audio presence LEDS around each input
button give an indication of input audio level. There is one LED for each channel. There are
also 4 presence LEDS around the MONITOR button which give an indication of output level.
Additional gain can be added by accessing the OUTPUT GAIN mode.
There are 2 stereo outputs which are available as simultaneous AES/EBU balanced XLRs, S/
PDIF unbalanced phonos or TOSlink unbalanced optical outputs. The output sample rates
are selectable via rear panel DIPswitches from one of 32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz,
176.4kHz or 192kHz.
The unit has TTL wordclock BNC and AES/EBU XLR synchronising inputs as standard and
optionally, the RB-SYA and RB-SYD synchronisation boards can be tted to synchronise
the unit to analogue or digital video signals. A rear panel DIPswitch block is used to decide
whether the unit is synchronised to Input 1 & 2, Input 3 & 4, the AES/EBU sync input, the
wordclock sync input or an optional video sync board. The DIPswitch block also selects the
synchronisation mode of the unit and the MONITOR button ashes whenever the unit is not
synchronised to an incoming sync signal. Selectable sync modes are as follows:
Master Mode
In this mode the digital output sample rate is simply set by, and locked to, the internal on-
board clock generator. No sync signal is used or required.
Auto Sync Mode
In this mode the digital output sample rate follows the selected sync input. When the sync
signal is not present the output sample rate will be set by, and locked to, the internal on-
board clock generator at the selected output frequency.

2Redbox RB-DMX4 User Handbook
INTRODUCTION
INTRODUCTION
1
Auto Lock Mode
The digital output sample rate follows the sync input. If the sync signal is removed then the
output sample rate will be set by, and locked to, the internal on-board clock generator at
the closest frequency available to the previous sync input.
Slave Mode
In this mode the digital output sample rate follows the sync input. When the sync signal is
not present the digital output is turned o.
There is a monitor socket on the front panel with a gain pot to allow you to monitor the
output of each channel. The monitored channel can be selected via a push button on the
front panel which, when held, can also supply up to 12dB of gain. If the level that is being
monitored is close to full scale, a 12dB attenuation can be added to the monitor channel
via a DIPswitch on the rear panel.
The unit can be placed in mono or stereo mode via rear panel DIPswitch. Stereo mode
allows you to monitor the two input pairs as stereo channels as well as controlling the
input gain as a pair, giving tied audio levels.
The RB-DMX4 has been designed to have a passive signal path through the main input, so
if power to the unit fails, signal inputs 1 & 2 are routed to outputs 1 & 2 and signal inputs
3 & 4 are routed to outputs 3 & 4. This is essential for applications such as installation at
transmitter sites, where a power failure to the unit should not prevent the audio input
signal from being output to the transmitter. Please note that this is not true for the TOSLink
outputs which are muted.
The RB-DMX4 can be controlled using Sonifex free software, SCi. Contact Sonifex for further
information if you have a particular requirement that isn’t catered for by the RB-DMX4 as
standard.
Fig 1-2: RB-DMX4 System Block Diagram
S/PDIF
S/PDIF
Optical
AES
Optical
S/PDIF
Freq Select
AES Sync
Word Clock
Video Optional
Digital Source
Select
Digital Input 1
Digital Input 2
Clock
Select
Master
Clock
Generation
VID RX
AES RX
WC RX
AES RX SRC
AES
Optical
S/PDIF
RX SRC
DSP
Digital Output 2
Digital Output 1
AES
Optical
TX
TX
Power
Failure
Relay
Power
Failure
Relay

Redbox RB-DMX4 User Handbook 3
2
FRONT PANEL CONTROLS & INDICATORS
FRONT PANEL CONTROLS
& INDICATORS
Front Panel Controls and Indicators
The LED on the front panel is normally red to indicate power to the unit.
OUTPUT MIX
DIPSwitches
SERIAL
LED
INPUT GAIN
Pots
Reset
Button
INPUTS 1 & 2
Source Select,
Indicators &
Input Presence
INPUTS 3 & 4
Source Select,
Indicators &
Input Presence
MONITOR
SELECT Button
& Output
Presence
Headphone
Jack
Level
Control
Knob
Fig 2-1: RB-DMX4 Front Panel Controls and Indicators
Output Mix Matrix Selection Using The Front Panel
DIPSwitches
The OUTPUT MIX front panel DIPSwitches are
concealed behind the screw panel located on the front
of the unit and they decide which input channels are
mixed to which output channels. There are 4 banks of
DIPSwitches, each representing an output channel.
To mix an input to that channel, simply lift the DIPSwitch for the desired input channel. In
total, 4 mono channels can be mixed together on each mono output channel.
This allows many mixing congurations and maximum exibility. Adding to that, mixing
can be achieved between all the dierent input types at all sample rates. See page 7 for
applications for the product using dierent matrix settings.
INPUT 1 & 2 Source Select Button, Indicators & Input Presence
LEDS
This button allows you to select which of the digital input sources
you would like to use. The three LEDs above the button illustrate
which source is selected. The button also indicates whether the
input is locked - it ashes green and red if the input is unlocked
and is unlit when locked.
The bicolour LEDs, marked ‘1’and ‘2’ , show input presence and give an indication of the
input level using the AES digital standard with the following colours:
-INF < -52dBFS = OFF
-52dBFS < -3dBFS = GREEN
-3dBFS <0dBFS = ORANGE
Fig 2-2: RB-DMX4 Front Panel
DIPSwitches
Fig 2-3: RB-DMX4 INPUT
1 & 2 Select Button

4Redbox RB-DMX4 User Handbook
2
FRONT PANEL CONTROLS & INDICATORS
FRONT PANEL CONTROLS
& INDICATORS
INPUT 3 & 4 Source Select Button, Indicators & Input Presence LEDS
The operation of this button is identical to the INPUT 1 & 2 button but acts on inputs 3 & 4.
INPUT GAIN Pots
These pots allow the gain of each individual channel to be
trimmed so that the perfect mix can be achieved. Simply turn
anti-clockwise to attenuate the level or clockwise to restore it.
Fully clockwise is unity gain. Fully anti-clockwise is muted.
In Stereo Mode, pots 1 and 3 control the gain for channels 1 & 2
and 3 & 4 respectively. See page 7 for further information.
MONITOR Button & Output Presence LEDs
Normally, this button displays the external synchronisation
status and the four LEDS around it display output presence. If
the selected synchronisation source is unlocked, the button will
ash green and red. A button press allows you to choose which
channel is output through the headphone socket and to set-up
the output gain.
For monitor selection, the button illuminates red, as does the LED of the selected channel.
For output gain, the LEDS around the button illuminate in green sequentially indicating
the level of gain applied.
MONITOR Button Modes
The MONITOR button has three modes of operation with dierent functions: Display Mode,
Monitor Output Select Mode and Output Gain Mode:
Display Mode
Display Mode is the default mode of the button. In display mode, the four surrounding
bicolour LEDs act as presence LEDs for the output channels. Marked ‘1’ to ‘4’ , the LEDs give
an indication of the output level using the AES digital standard with the following colours:
-INF < -52dBFS = OFF
-52dBFS < -3dBFS = GREEN
-3dBFS <0dBFS = ORANGE
0dBFS/ CLIP = RED (AGC Operational)
Note re Clipping: The AGC is working on a channel if its output presence LED is red. The
mixing in this unit is achieved by the summation of 24 bit audio values. The total of this
summation could, if uncorrected, breach the upper limit of a 24 bit number, which would
lead to clipping. The unit detects these occurrences and adds an instantaneous attenuation
to bring the signal in range again. This attenuation factor will decrease on a slow decay
until 0dBFS is achieved, or until another breach occurs. The slow decay eliminates any
breathing or pumping eects in the audio.
If the unit is set to be synchronized externally but is not synchronized, the button ashes
green and red continuously. If it is synchronised, or the unit is set to MASTER sync mode,
the button is unlit.
Fig 2-4: RB-DMX4 INPUT
Gain Pots
Fig 2-5: RB-DMX4
MONITOR Button

Redbox RB-DMX4 User Handbook 5
2
FRONT PANEL CONTROLS
& INDICATORS
FRONT PANEL CONTROLS & INDICATORS
Monitor Output Select Mode
To enter Monitor Output Select Mode, simply press and release the MONITOR button.
The button turns red and the surrounding LEDS now display which output is selected for
monitoring, in red. This mode will last for two seconds, which is refreshed every time the
button is pressed and released. If the unit is in Stereo Mode, LEDs 1 & 2 illuminate together,
as do 3 & 4. See page 7 for congure the unit in Stereo Mode.
Output Gain Mode
To enter Output Gain Mode, rst enter Monitor Output Select Mode and select the
channel which you would like to apply gain to. Within two seconds, press and hold the
MONITOR button until the button changes from red to green. On release of the button, the
surrounding LEDS will now switch to display the current output gain for this channel. Press
and release the button to choose the output gain levels from one of:
LED 1 Green: 0dB
LED 2 Green: +3dB
LED 3 Orange: +6dB
LED 4 Red: +12dB
After choosing your required setting, press and hold the button until it changes colour
from solid green. This will return the button to the Display Mode.
Note: Make sure that you check the presence LEDs to ensure that the output is not clipping.
SERIAL LED Indicator
If the rear panel Serial Mode DIPSwitch 11 is ON, then this LED illuminates. In
this mode, the unit is being controlled serially using the Sonifex SCi software.
Headphone Output
The front panel headphone output is a ¼”(6.35mm) stereo
jack socket capable of delivering over 80mW into 32Ω - 600Ω
professional headphones at full volume. Higher impedance
headphones may be used at reduced levels. Lower impedance
headphones should not be used.
Please be aware that this headphone amplier has been designed
to cope with the varying dierent headphone and full scale line-
up set-ups that are used. Consequently, the monitor attenuation
DIPSwitch 10 should be turned on if the output sounds very loud
and distorted at any time.
LEVEL Control
The front panel LEVEL control is a potentiometer that adjusts the level of the monitor
output and provides a gain range of -70dB to +12dB.
Reset Button
In the unlikely event that the RB-DMX4 unit fails to respond, press the reset button to
reboot the unit (see Fig 2-1 for location).
Fig 2-6: RB-DMX4 Serial
Control Indicator LED
Fig 2-7: RB-DMX4
Headphone Output &
Level Control

6Redbox RB-DMX4 User Handbook
3
REAR PANEL CONTROLS
REAR PANEL CONTROLS
Rear Panel DIPSwitch Controls
The SETTINGS DIPSwitch block on the rear panel is used to
congure the RM-DMX4:
Master Mode Sample Rate Selection (DIPSwitches 1-3)
These DIPSwitches allow you select which sample rate the output is set to when the unit is
synchronised to the Master Mode. Set the DIPSwitches where:
Sample Rate (kHz) DIPSwitch 1 DIPSwitch 2 DIPSwitch 3
32 OFF OFF OFF
44.1 ON OFF OFF
48 OFF ON OFF
88.2 ON ON OFF
96 OFF OFF ON
176.4 ON OFF ON
192 OFF ON ON
Synchronisation Source Selection (DIPSwitches 4-6)
These DIPSwitches allow you select which input sync source is used to synchronise the unit
to. Set the DIPSwitches where:
Synchronisation Source DIPSwitch 4 DIPSwitch 5 DIPSwitch 6
Input 1 & 2 OFF OFF OFF
Input 3 & 4 ON OFF OFF
AES/EBU Sync Input OFF ON OFF
Word Clock Input ON ON OFF
Video Sub Board OFF OFF ON
Synchronisation Mode Selection (DIPSwitches 7-8)
These DIPSwitches allow you select the active sync mode. Set the DIPSwitches where:
Synchronisation Mode DIPSwitch 7 DIPSwitch 8
Master Mode OFF OFF
Auto Sync Mode ON OFF
Auto Lock Mode OFF ON
Slave Mode ON ON
Fig 3-1: RB-DMX4 Rear Panel
DIPSwitch Block

Redbox RB-DMX4 User Handbook 7
3
REAR PANEL CONTROLS
REAR PANEL CONTROLS
Stereo/Mono Operation of Input Gain and Monitor Select (DIPSwitch 9)
This denes whether the unit operates the input gain and monitor functions as a stereo
pair or as mono channels.
Mode DIPSwitch 9 Description
Stereo ON
When ON, the gain applied to input 1 using pot
1 also alters the gain for input 2.
Also when ON, the headphone monitor outputs
a stereo signal made up of either Input 1 & 2 or
Input 3 & 4.
Mono OFF
When OFF, the gain of each channel is
controlled individually by a gain pot.
In Mono Mode the selected signal is sent to left
and right earpieces of the headphone output.
Monitor Attenuation (DIPSwitch 10)
This denes whether the monitor signal is attenuated by 12dB. This is useful if you’re using
low impedance headphones which are too loud in everyday use.
Mode DIPSwitch 10 Description
Attenuated ON When ON, the monitor signal is attenuated.
Unattenuated OFF When OFF, the monitor signal is unaected.
Serial Mode (DIPSwitch 11)
This denes whether the unit is in serial mode. In serial mode the unit is controlled by the
serial port, not by its DIPSwitch settings. For example for use with the Sonifex SCi software.
Mode DIPSwitch 11 Description
Serial Control ON When ON, the unit is in serial mode.
DIPSwitch Control OFF When OFF, the unit is in normal operation.
Boot Mode (DIPSwitch 12)
With this DIPSwitch ON, the unit powers up into ‘Boot Mode’. In this mode, the rmware
in the unit can be upgraded using the SCi software. Note that this would be useful if
a rmware update to the unit was interrupted, or corrupted which left the unit in an
inoperable condition.
Mode DIPSwitch 12 Description
Boot Mode ON When ON, the unit is in Boot Mode.
Normal Operation OFF When OFF, the unit is operates normally.

8Redbox RB-DMX4 User Handbook
4
APPLICATIONS
APPLICATIONS
Applications of Use
Each physical input connector (INPUT 1 & 2 or INPUT 3 & 4) supplies the unit with two
channels of audio data, left (1 and 3) and right (2 and 4). Similarly, each physical output
connector (OUTPUT 1 or OUTPUT 2) supplies the outside world with two channels of audio
data, left (1 & 3) and right (2 & 4). These inputs and outputs can be congured in a number
of ways for dierent applications. Here are a few suggested methods of use:
Stereo Mix of Two Stereo Digital Inputs
Connect two stereo input sources and select on the front panel.•
Raise DIP switch 1 and 3 ON for OUTPUT MIX bank 1.•
Raise DIP switch 2 and 4 ON for OUTPUT MIX bank 2.•
Connect OUTPUT 1 to output equipment.•
Mono Mix of Four Input Sources to Create your Own Stereo Output
Connect four mono inputs (for example four dierent musical instrument feeds) to the•
unit and select on the front panel.
Select which inputs you would like on the LEFT of your stereo output and select ON for•
OUTPUT MIX bank 1.
Select which inputs you would like on the RIGHT of your stereo output and select ON•
for OUTPUT MIX bank 2.
Connect OUTPUT 1 to output equipment.•
One to Four Mono Distribution/ Creating Dual Mono Outputs
Connect one mono input to the unit INPUT 1 and select on the front panel.•
Raise DIP switch 1 ON for all OUTPUT MIX banks.•
Connect OUTPUTs 1 and 2 to output equipment.•
Two to Four Mono Distribution Or Creating Dual Mono Outputs
Connect two mono inputs to the unit INPUT 1 and select on the front panel.•
Raise DIP switch 1 ON for OUTPUT MIX banks 1 and 2.•
Raise DIP switch 2 ON for OUTPUT MIX banks 3 and 4.•
Connect OUTPUTs 1 and 2 to output equipment.•
Four Channel Sample Rate Converter
The RB-DMX4 can be used as a sample rate converter or an input/output converter. To use
the unit as a “Straight Through” device and take advantage of those features alone:
Connect all desired inputs to the unit and select on the front panel.•
Raise DIP switch 1 on OUTPUT MIX bank 1.•
Raise DIP switch 2 on OUTPUT MIX bank 2.•
Raise DIP switch 3 on OUTPUT MIX bank 3.•
Raise DIP switch 4 on OUTPUT MIX bank 4.•
Connect the desired connector of OUTPUT1 and OUTPUT 2 to the output equipment•
and set the sample frequency that you want to convert to using the SETTINGS
DIPSwitches on the rear panel.