Control of SQ sound desk using MIDI

[Paul]

A few people have asked about this recently. Attached is a QLab Workspace which contains MIDI cues to control the A&H SQ series of digital mixers. The MIDI cues will allow recalling scenes, muting of channels/groups and setting of levels. This does not require the A&H MIDI driver.

To get started with this

• Connect the SQ to the Mac via USB
• Make a backup of any Workspaces you are currently working on
• Start QLab and load this workspace; got to Settings->MIDI and create a MIDI patch for the SQ
• On the SQ go to Utility->General->MIDI and set MIDI channel number to 1 and Linear fade law.
• Create Start cues which target the Scene Recall/Mute/set level cues in the SQ control cuelist
• See the examples cue list for suggestions on how to use

A&H SQ is a series of digital mixers with 48 channels, 12 mixes (Auxes/Groups), 4 effects sends. It has a USB interface which supports 32 audio interface and a virtual MIDI port (the USB is class compliant, so you just connect to the Mac and then set up the MIDI interface in QLab Settings->MIDI

The workspace contains  5 cue lists 

• Main Cue List - this list is empty
• SQ Control - the MIDI cues to control the SQ
• Examples - some examples of using the MIDI cues
• SQ Levels demo - MIDI cues to control levels of DCAs, channels to LR, FX sends
• Scripts - the scripts used to create these MIDI cues

To keep the size of this workspace manageable it contains limited number of MIDI cues (120 scene recalls, mutes/unmutes for 32 channels, The SQ Levels demo cue list contains cues for 3 channels to LR mix, FX sends at 3 different levels.  This is just an illustration - you can create level cues from the interactive levels script in the scripts cue list. 

Using these cues - see the Example cue list

The example cue list contains some Start cues which target the MIDI cues.

To recall a scene, in your main cue list, make a start cue with the target “Sc1”. Note if you try to recall a scene which has not been Stored on the SQ nothing will happen.

Use scene recalls whenever you can; you can control things (like EQ settings) which you can’t control via MIDI and it reduces potential confusion by keeping all the settings in the mixer.

The other example cues show Start cues to mute and unmute individual characters M, A, S on channels 1-3 and a chorus on channels 4-6. It also shows turning on reverb for character A (assuming FX1 rack has been set up with a reverb and the return set). If you create Start cues which cue numbers which relate to the characters in your show, you can then use these more easily in your main cue list. This is most useful when you have a stage manager/operator who just needs to turn on a mic occasionally; it is always advisable to keep the mixer in reach so they can adjust the fader if needed.

For complex shows, you can set up mute groups and mute those or recall their settings in scenes.

How the MIDI cues work

A&H SQ series use NRPN (Non-registered parameter numbers) for MIDI control, which are sent as 4 MIDI CC (continuous controller) messages. Unfortunately QLab can only send single CC messages in a MIDI cue. But we can use a kludge, a feature of the MIDI protocol which says you can’t send a “Status byte” in a SysEx message. So we can create CC messages and put them in a QLab MIDI cue with SysEx type and those bytes will be sent and interpreted as CC messages.

Note the MIDI channel number is contained in the CC message, so if you need to change the MIDI channel on the SQ you will have to re-run the scripts to re-create the MIDI cues. But you there should be no reason to change the MIDI channel used by the SQ

For details of SQ NRPN and MIDI control of A&H see

https://www.allen-heath.com/media/SQ-MIDI-Protocol-Issue3.pdf

Scripts

The scripts cue list contains the AppleScript scripts which were used to generate the MIDI cues. There are scripts for making scene recalls, mutes/unmutes, assigns and levels. These contains comments and should be structured in a way that you can adapt them. A few things to bear in mind; MIDI is 7 bit which makes calculations slightly more complicated; AppleScript does not understand hexadecimal (required by SysEx messages), so the calculation and conversion to hex is done via awk/shell script. The levels are only approximate, just using the coarse value (due to scaling it is difficult to calculate these values). 

[Jake Perrine]

I finally got a moment to dig into this, Paul, and it is truly awesome!  I've been wanting to do just this for some time, but could not get very far using four MIDI Q's per Q and no script knowledge... this solves both of those problems for me!  Amazing.  I'm going to use this extensively and let you know how it goes!  Sincere gratitude to you!

[Jake Perrine]

Also, is this only possible over USB?  Would MIDI cues over LAN work in a similar fashion?  Would I need the SQ MIDI app for that?  Just curious if you've tried it.

[Paul]

I don't know. I'm not sure why you would want to do that, what advantage it would give?

For me, if I am mixing a show, I want the desk and Qlab computer near to each other so a 2m USB lead is fine; and generally I used the USB interface for multi-channel audio interface (32 out, 32 in), which you won't get over the control network. (The MIDI and audio interface over USB are "class compliant" which means they work without having to install any other software).

So I've not had a reason to try it.

I think it might work using a midi-network converter software (perhaps rtpMIDI) but there is no standard for midi over network and I have heard varying reports of reliability from other people.

[Jake Perrine]

In our theatre, we have a few different options of where we can run Qlab to control lighting, projections, sound playback, etc. whereas the mixing position (FOH) for the SQ is fixed.  Often the preferred Qlab position is upstairs behind the glass of a tech booth window, which obviously does not work for mixing audio.  There is a Mac mini next to the SQ at FOH which does multitrack playback and recording over USB regularly.  I could see using network cues from the upstairs Qlab triggering your MIDI mutes and fades at FOH remotely - that might be a good solution.  I have also tried a 30’ powered USB cable to upstairs, but I find that when I have lighting cues (over ArtNet) and USB to the SQ on the same machine, I get crosstalk between the two: moving a fader on the SQ will send errant messages to the lighting (!) which I’ve never been able to track down and eliminate.  So I try to keep the lighting Qlab and the USB to SQ Macs separate for now.

Cheers,

Jake Perrine

Artistic Director 
Orcas Center
c: 360-317-8751
www.orcascenter.org

Upcoming Events

--
Contact support anytime: sup...@figure53.com
Follow QLab on Twitter: https://twitter.com/QLabApp
User Group Code of Conduct: https://qlab.app/code-of-conduct/
---
You received this message because you are subscribed to a topic in the Google Groups "QLab" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/qlab/GGhjGFGIcgM/unsubscribe.
To unsubscribe from this group and all its topics, send an email to qlab+uns...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/qlab/eb419571-3014-4a30-bd23-11b8e6f0fbb2n%40googlegroups.com.

[Paul]

Ok so I've tried this MIDI over network, using the built in MacOS Audio MIDI Studio - Network setup but I could not get it to work; although I can ping the SQ and it says it connects, the midi interface shows up in Qlab but no MIDI commands work (same commands from QLab work fine over USB)

So I downloaded and installed the A&H MIDI Control v2.01 (https://www.allen-heath.com/midi-control/) - you need to configure this for mixer type (SQ), Protocol (MIDI Thru), connection (TCP/IP) and the IP address of your mixer. Then adjust the MIDI patch in QLab - the A&H software unhelpfully shows up as "MIDI Control 1 (unknown manufacturer)". This does work (using the same MIDI messages for scene recall, ch mute etc as in my workspace above). Recommend you have everything configured on the show control network with a static IP address.

BUT regarding your situation, I would be very cautious about controlling the mixer from a physically remote location - there is a chance of feedback which would be difficult to suppress. (if any actor/presenter leaves a handheld microphone near speaker on stage, for instance). I would move the Qlab machine to the FoH mixing position (and get the advantage of 32 channel USB audio interface) or leave scene recalls to the person in front of the mixer.  If you are just doing playback (no microphones) then you should be able to control all the levels from within Qlab. If necessary you can trigger lighting and video cues remotely (eg if more convenient for projector connections).

[Jake Perrine]

Paul,

Awesome! I will give it another shot with A&H MIDI control.

Remote mixing: Yes, that is sound advice (heh).  The idea would not really be fully automated mixing of the entire show, but automating mutes and music playback levels at least would take some of the heat off the FOH mixer for a large show.  

I’m excited to try this!  Thanks for all your help!