Control of Digico desks with OSC – Part 1

A three part series about practical ways to use OSC to remotely control Digico desks. I don’t pretend to be an OSC expert but the information and solutions included in this series have been tested and work well.

 What is OSC

Open Sound Control or OSC is a network protocol for remotely controlling specific functions of audio devices. Originally developed for electronic music it has seen significant adoption in live show applications including theatre, drama, dance and multidisciplinary performances as a means to control and coordinate technical equipment.

There are a lot of devices that are OSC capable including synthesisers, DAWs, software controllers, SFX generators and even projection systems.

 Why use OSC

 I’m sure many of you are thinking, can’t MIDI do the same thing. Well, yes and no. There are several advantages to OSC that make it easier to work with and more flexible than MIDI.

 Pros

OSC commands use natural language rather than strings of hex code.

OSC is networkable so remote control is easy and flexible, even across sub-nets.

OSC is implemented independently by each equipment manufacturer and can offer much deeper control levels than MIDI.

OSC is bi-directional and way faster than MIDI

 Cons

OSC protocol has no handshake or error correction. Your messages launch into the big wide open network and your only feedback is if the control actually works on the target device, just like MIDI.

OSC command language is implemented somewhat differently by each manufacturer. Fortunately most instructions are very similar, especially amongst DAW’s.

Not all manufacturers publish their OSC command sets but they are quite easy to sniff out.

OSC networking protocols

OSC uses standard IP addressing using ports specified for incoming and outgoing messages. e.g.

192.168.1.200:8000 for incoming messages

192.168.1.200:9000 for outgoing messages

This allows every device on a network to send and receive OSC commands.

What live sound desks implement OSC

Digico, Yamaha Rivage and Behringer/Midas X32 platform. Unfortunately the Yamaha CL series and Avid desks have no OSC implementation of any kind.

If you are an X32 platform user you should study the extensive publications by Patrick Maillot who has a ton of excellent information and practical applications. You can start here https://awesomeopensource.com/project/pmaillot/X32-Behringer

For Yamaha Rivage series desks the OSC command structure is documented at  https://uk.yamaha.com/files/download/other_assets/5/1407565/RIVAGE_PM_osc_specs_v102_en.pdf

If you are a regular Yamaha CL desk user then I strongly recommend you to the extended control programming published by Andrew Broughton on his site  https://discourse.checkcheckonetwo.com

Andrew is also the author of an internet spanning remote control protocol for Yamaha CL desks called Remotely Possible. https://discourse.remotely-possible.ca/

For Avid desks check out the Avid native network control protocol called Eucon. You can check all the features here https://www.avid.com/products/avid-control/features

Allen & Heath desks don’t seem to have any published OSC functions but have a reliable MIDI over IP function.

If you are a Digico user then please read on.

How does remote control work with Digico desks - About Console Network

What is interesting about the Digico SD series software is that from the beginning it has offered complete duplication of the desk surface that allows remote operations over a network. Digico calls this “mirroring” and it works well for one or two remote computers as well as remote desks. Here is a typical setup screen,navigate to

Main Menu/Network

 This screen shot shows two computers on-line with each other and full mirroring is possible even though they are both using the off-line editor. The A and B devices (shown as not found) would be physical desks if they were connected to the network. The physical desk can be mirrored by the remote computers which will then operate the hardware desk remotely and vice versa.

About OSC Control on the Digico platform

Digico use OSC commands to implement their IPad control surface, Klang for monitoring and L-ISA spatial controls. Unlike other manufacturers the Digico protocol only works for one IPad at a time so having an eight piece band all with their own pad based monitor mixing is not officially possible in the Digico world. Digico now allows some limited control of external devices from the desk surface, enough to control an external cue manager (e.g. QLab) or a DAW.

Despite these apparent limitations it is still possible to use OSC to control a Digico desk for a full range of useful applications, including monitor mixing.

Practical applications of OSC on Digico desks

Macros. There are a huge range of things you can do on a Digico desk with just a button push, it seems that every possible desk control is available to the Macro system. Unfortunately the macro window is small and only has 12 slots, it’s difficult to get to anything quickly that is not in one of those slots. Yes there are Macro buttons on the desk (the number varies with the model), often two or more button pushes are needed.

 A touch screen laptop with control software can offer page upon page of 20 – 30 buttons each, or faders, or radio buttons all with unique colours and functions. How about screen brightness on a fader, or a monitor mix select button with faders linked to control groups, on a tablet.

 Scenes. Scenes are easily recalled using OSC, useful if you only use scenes for major and infrequent changes (e.g. band changeovers). Anything more complicated is best handled by cue manager such as Qlab (Mac only) or Multiplay (Win based). These are flexible and sophisticated so there is not much point in re-inventing them yourself. Both of these cue managers can use multiple protocols including MIDI and OSC.

 Individual Channels. Remote channel control in a more complex show environment e.g. presenter mic volume and mute, playback or DJ remote volume and mute.

 Fast operation of menu commands. For every digital desk there are commands that are hidden deep inside nested menus, Digico desks are no exception. So to quickly change bridge lights levels or change the decay time on a reverb FX a screen based fader or rotary is much faster that banging through the menus.

 Miniature mix page for limited use. Typically this would include having a RF mic and laptop playback for a corporate presentation that can be operated by the user without needing access to the desk or a 4-hour union call for a desk operator. Great in a theatre environment. Limited monitor mix controllers can be setup the same way.

 Digico OSC Commands

Confusingly a lot of OSC literature refers to “OSC addresses” when in fact the information in the addresses is a set of commands. From here on out I will refer to all these messages as commands. Here’s an example

 /Input_Channels/1/mute FLOAT(1)

This command is addressing an input channel, channel 1, and setting the mute to an ON condition.

 /Input_Channels/1/mute FLOAT(0)

This command sets the mute to an OFF condition.

 FLOAT specifies the numerical data type. A mute button is a boolean device; it has two conditions true (1) and false (0). Other commands can include parameters with the numerical type integer or string type for text.

Digico do not publish their OSC command protocol but a few people have “sniffed” out various parts using a network program that listens for OSC commands on specific ports. An extensive list of Digico OSC commands is included in the side panel of this blog under "Pages".

 Configure a test setup for controlling a desk

Fortunately the off-line editor is essentially the same software that controls the desk hardware in real time. Within hardware limitations you can use it as if it were a real console. To setup a test I recommend running the Digico offline editor on one computer, configuring it for external control and then running test controls from another computer on the same sub-net.

e.g. editor on computer 192.168.0.16 and controller on 192.168.0.23. See this in the following examples of the desk setup.

 Main Menu/Setup/External Control

Digico has a restriction of only allowing one device of one type to be enabled. Presumably this is an internal software issue that hopefully they will update.

 Another restriction is that only one device can get feedback from the desk and it has to be added as a “Digico Pad” in the add device drop down. It can be any OSC controller, doesn’t have to be the Digico app running on an IPad. An additional “OSC” type device can be used but it is one way control only.  This explains why “officially” only one IPad can be used for external control on an SD system.

Luckily there is a work-around. You will notice that each device in this list has unique Send and Receive port numbers. Most OSC implementations allow multiple controllers to send to the same target receive port. Usually they need to have different network addresses, on the same subnet, with seperate local receive ports.

To clarify, in the above graphic, a controller device with a send port of 8006 and receive port of 9006 can send and receive commands OSC commands from the Digico Pad device “clive 11D” and get full feedback.

Other controllers which send on port 8006 can also control the Digico OSC device, without any feedback. They will each need a unique IP address, on the same sub-net, and unique local receive ports to prevent port lock-outs. Communication is one way only, no feedback. Other controllers can send commands to the OSC device “clive 11C” at receive port 8004, without feedback.

So a likely remote OSC control setup could be a “Digico Pad” device running control software and getting full feedback. Additional “OSC” controllers could issue one-way commands without feedback.

Conclusion of Part 1

We have discussed what OSC is, what it does along with some examples. We also showed the way to setup a Digico desk, or off-line editor, to receive and issue OSC commands as well as how to connect for remote operation. In the next part of this series we will look at three different software programs that allow you to build faders, switches, momentaries and rotaries that issue and respond to OSC commands. 

Please check out the list of Digico OSC commands included in the side panel of this blog under "Pages".

                                                                                                            © Clive Alcock 2023

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How to write a Sound System Specification

It’s probably happened to you already and if it hasn’t, it will. Your Artist Manager, Tour Manager, Production Manager or someone will ask you to come up with an audio spec for an upcoming tour or series of shows. This might be for local promoters to supply or to get quotes from production companies. Note that the system specification is a technical document; dressing rooms, catering, transportation, security etc should be a whole seperate document.

It’s not particularly hard to write a list of what you want but that is not really the point. What you really need is a brief but accurate description of the production equipment that is acceptable and necessary for your show while allowing for a range of options of brand, size, style and function in your choices. You also have to be reasonable in your demands if you want to be taken seriously.

A specification that includes “SPL level of 120dB from 40 – 20Khz throughout the venue” is not a realistic or reasonable specification, neither is asking for a 64 input desk for a 4 piece band performing in a pub.

Format

Let’s talk about the format of your document before you start writing lists. You need a header or title at the top and I suggest a contact information line right below that.

I usually put the document title, my name and the date prepared and a “Page X of Y” in a footer. That way you can always check if it’s the correct version that they are quoting on.

Here’s an example of a header with contact line

Artist Name - European Tour 2023 – PA System Specification
Please email complete system specs of what you plan to supply to the Artist's Production Manager.
Production Manager, emailaddress@somemail.com. Phone xxx,yyy,zzzz
Sound Engineer, emailaddress@othermail.com Phone aaa,bbb,cccc

Here is an example of a footer

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Artist Name – PA System – Europe Tour 2023         October 5, 2022         Page 1 of 3
                                                                                  

It’s easiest if you use a word processor to setup a template so that you don’t have to re-invent the page layout every time you need to write a spec. Likewise with Input Lists.

Sections

You can make it easier for your suppliers to understand what you want if you have clearly delineated sections to your spec. If a supplier is only dealing with part of your spec it makes it much easier for them to find what is needed without having to read the whole thing.

My section headers and sub headers usually read like this

Audio System

FOH Speaker System      

General description of typical venue sizes, average SPL levels and number of technicians to be supplied (include “English speaking”).

Approved Speaker Systems

Choice of three major brands, model numbers and quantities of each. Complete list of necessary rigging, hardware, cabling and packaging

FOH Mix - Required Equipment
Specific desk brand, model, racks and cabling. Include Multicores 

Other FOH Equipment 

Outboard, playback, DSP, Com, Talkback, measurement equipment, network switch, patch cables

Monitor System 

Indicate monitor mix location on stage (e.g. SL)

Required Equipment 

Specific desk brand, model, racks and cabling

Monitors & Stage Audio 

List of wedges, ears, RF mics, antenna systems, desk patch and accessories

Microphones DI’s Stands Best to list it and to include a spreadsheet patch sheet, including the musicians names 

 

Stage Cabling 

Stage input boxes, mults, stage AC, instrument cabling, wedge cabling, typical cable lengths, AC Distribution and cross connects.

 

Other 

This is really a catch all but I keep it short and to the point. Use it to emphasise specific things that are important to your show. See the example below.

Example Audio System Specification

2. AUDIO SYSTEM  REQUIREMENTS

 FOH Speaker System

Typical FOH speaker system to accommodate a variety of halls in the 1500 to 5000 seat size. For larger venues please consult with the Artist’s Production Manager. Supply with one fully trained and experienced English speaking system technician.

Typical System

24        Line array speakers – 12 per side main arrays

4          Dual 18" subwoofers or 6 single 18" subwoofers

4          Fill boxes, inner, front & outer

6          Low line lip fill speakers

2          Sets bumpers & rigging hardware to accommodate main array speakers

1          Package of chain motors, motor controller and rigging. Rigging package to include all necessary parts to fly all the house speakers, including fill boxes if necessary. Include spare pins, steel, shackles & necessary hardware for all speakers. Rigging attachment points must each be rated for full load of array. Include safety cables as and where required by local codes. Include sufficient tie lines for orienting all flown speaker arrays.

1          Meyer Galileo DSP, or equivalent, signal distribution and speaker management system. DSP to  accept inputs from XLR connectors as either analog or digital signals. For stage mounted DSP supply wired ethernet network access to allow operation from FOH. Software speaker management (e.g. d&b R1 V2 or L' Acoustic Network Manager) is acceptable as long as all EQ, delay and zoning functions are fully accessible and sensibly templated. Supply a laptop computer with correct software versions to control loudspeaker management systems.

1          Lot of all necessary AC power distribution and speaker cabling.

2          Bumper mounted laser pointers and inclinometers (1 per array) to permit accurate main array orientation.

System technician must have complete control of the whole speaker system with the ability adjust the system to suit the artist’s FOH engineer. Supply disto measurement devices to calculate optimum array configuration using manufacturer's prediction software.

 Acceptable FOH Speaker Systems 

L' Acoustic K2 or Kara. d&b KSL, J or V-Series. Meyer Lion or Leopard. Include all necessary amplification and DSP processing. Smaller enclosures may require higher quantities to be supplied. Other brands and types may be acceptable, please check with us first, do not assume anything.

FOH Mix

Preferred Equipment.

1          Digico SD-12 with D2 or SD Rack, minimum 48*16, with fibre or coax cards. Ensure that current firmware is installed.

1          Set FOH 100m signal mults (fibre or coax). Include copper returns for com and talkback and any required feeds to stage. Include AC power from stage to FOH with minimum 4 free outlets.

Alternates:    

1          Digico SD-9 with SD, MADI or D2-Rack and appropriate bridging boxes if required.

1          100m 2 circuit coax or fibre cable set to connect stage rack to FOH.

Other FOH Equipment

1          Shure SM58S switched talkback mic to monitor desk & stage

1          Intercom station with belt pack, standalone strobe indicator light and telephone handset to connect directly with the monitor desk position.

2          Short tripod boom mic stands for system measurement mics

2          each 15m & 30m XLR cables for system measurement

1          Lot short (3m) analog and AES XLR cable and any other required cable for FOH patching and general use. Include a complete set of audio adapters including  male & female TRS-XLR, male and female XLR turnarounds, phase reverses and pin 1 lifts. Include suitable music playback patch cables.

Monitor Rig

Down Stage Left setup position. Supply with one fully trained and experienced English speaking system technician who must have complete control and access to the system.

 Preferred Monitor Console

Avid S6L digital desk c/w 1 Avid SL64 stage rack, minimum 48x16 configuration.  Include working console lamps with spare bulbs, suitable VGA monitor, USB keyboard and mouse. Ensure that the most current firmware is installed.

Alternate Console

Avid SC 48 digital desk with 48 X 16 configuration. Include working console lamps with spare bulbs, suitable VGA monitor, USB keyboard and mouse and 8 TRS-XLR3M and TRS-XLR3F adapters.

Monitor & Stage Audio Equipment

1          48 * 2 transformer isolated splitter with two 25' (8m) mult tails to reach monitor and house stage racks.

1          lot XLR and mult cabling for monitor signal patching, plus suitable spares

7          low profile high power wedge monitors self powered or with amplification/processing for 6 mixes ( Meyer MJF210 preferred, d&b M4 and L`Acoustic X12 are very acceptable)

2          wireless ear monitor transmitters - prefer Shure PSM1000 dual channel

4          wireless ear monitor body packs to match

1          Shure antenna distribution system for ear monitor system

1          Helical Antenna

1          Switched talkback mic - Shure SM58S or similar

1          RF Handheld mic kit complete – Prefer Shure ULXD or Axient.

4          Separate line level audio transformer isolation boxes with XLR connectors and pin 1 lifts.

2          Com stations/beltpacks with indicator light, 1 dual muff headset, 1 telephone style handset, 1 Clearcom beacon.

Include all necessary hardware, power distribution & signal cabling for all monitors and associated equipment along with batteries for ear monitor packs.

Include a complete double set of audio adapters including male & female TRS-XLR, male and female XLR turnarounds, phase reverses and pin 1 lifts.

Microphones, stands, DIs and stage cabling

See attached list for details & distribution of microphones that you supply. We supply some microphones and DI's as indicated on lists. Mic Stands - all black.                           

Audio Stage Cable

10        10’-12' (3m) mic cables

30        20’-25' (6m) mic cables

2          50’ (15m) mic cables

3          12-16 channel stage input boxes (FXLR) with multipin disconnects

3          75' (23m) mult extension cables to match stage input boxes

1          50' (15m) mult extension cables to match stage input boxes

3          12-16 channel multipin fanout to XLRM for stage rack patching

4          ¼” X 3’ (1m) instrument cables

4          ¼” X 10’ (3m) instrument cables

4          75' (23m) Monitor cable sets to match wedges

2          20’-25' (6m) Monitor cable sets to match wedges      

2          10’-12' (3m) Monitor cable sets to match wedges

2          230V/120V transformers with US Edison style outlets - 15A output per device

2          US style Edison quad outlet boxes - 50’ (15m)

2          US style Edison quad outlet boxes - 15’ (5m)

Other

All signal distribution must be confirmed in positive phase, clean and free of any ground loops, hums or buzzes. 

Rigging hardware must be certified, of a type approved by the speaker manufacturer and installed by an experienced & certified rigger.

Electrical power services must conform to national and local codes and be connected by a certified electrician. Electrical service must have secure service earth and demonstrate zero potential difference between neutral and earth. Generators must be earthed at their location and be bonded to stage and roof structures.

IMPORTANT

Parts of this performance are extremely quiet, Generators need to be placed far enough away as to not be heard on the stage or in the audience. Noisy HVAC systems should be turned off!

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 Input List 

This is easiest to format as a spreadsheet that can be copy and pasted into your main document.

Example Input List  

 

• Be sure to date your list so you know the show technicians have the correct version when you do your advance phone calls.

• I use Splitter (or Main Rack) input as the definitive stage input patch. Both FOH and Monitor desks may be patched differently depending on each engineers requirements.

•  I use shorthand for stands and put a note underneath the patch. Typically SRB, TRB, STB, and TTB for short or tall, round or tripod base stands and clip for Sennheiser 604’s or Beta 98’s that don’t need a physical stand

•  I like to include the musicians’ names; it helps the local techs and stage hands when working on stage.

•  Comments may be used to indicate which mics or other special pieces you may be supplying yourself.

• A, B, C and D refer to stage patch box cross patch channels. Include “direct to split” if that particular channel is a direct patch.

Stage Diagram

This is another essential piece of information. It doesn’t need to be artistic, named rectangular blocks in an approximate representation of your stage setup is enough.

Show instrument, amplifier and drum kit positions as well as vocal mic locations and musician names. Including AC drop box locations and riser locations and dimensions is really helpful.

Name the downstage, stage left and stage right edges, include monitor desk location and any other stage tech locations (e.g. guitar world). Make sure your stage diagram exactly reflects your input patch. Some people include a short form input list on the bottom of their stage diagram.

Example Stage Diagram

This diagram is from a festival I worked on several years ago, with the artists names redacted.

 Final Comments

Having good technical documentation is essential, but it is no substitute for a phone call to advance the show which is best done a couple of weeks in advance.

 Have your part organised and together. When you show up on stage to setup bring spare copies of your input list and stage plot.  Make sure you have current desk files that correspond to your input list for both monitors and FOH.

Be prepared for desks that do not have the most recent firmware. For digital desks, older firmware will not load files made with more recent versions. I carry files made with firmware that is several years old, just in case.

Be prepared to accept alternates, especially for one off gigs like festivals. If they can’t supply your “must have” desk then you need to build your show with an off line editor for the desk they can supply. I carry files for Digico, Yamaha and Avid desks. There will be rough spots for sure (how do I route to matrix on this desk?) and you’ll probably have to lean on the house mixer or system tech for help.

You should encourage your fellow LIghting, video and backline techs to follow similar guidelines for specifying their parts of the technical specification. In the end these will all get assembled into one master document.

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                                                                                                     ©  Clive Alcock - 2023