[LAU] Behringer and Linux

[Len Ovens]

On Sun, 29 Mar 2015, Jostein Chr. Andersen wrote:

Beware, this message is kind of scrambled as I started it after reading 
the x18 manual and have edited it as I found new sources of info which I 
have tried to note.

While I am quite happy just now with the D66 as an AI, I am well aware 
that it's days are numbered. The computer I am using it on is less than a 
year old and has a PCI slot. But either it or the D66 may get faulty and I 
will be looking at something new. I was thinking that something like the 
allen & heath QU series mixers would make a good AI and now the X32 looks 
to add to the mix. Either one would give me a lot more I/O than 6 plus a 
control surface better than the MCP for about the same price as an 8i/o AI 
plus ADAT to expand to 16i/o plus an MCP controller (looking at the 
16input models on both).

> It seems to me that the Behringer folks have done a Linux version of all 
> their editors for their entire range of digital mixers and also Android 
> versions of the GUIs. I'm pretty impressed!

All the work has already been done. A look at the "Quick start manual" is 
quite instructive. This is really a USB2 Audio IF with mixer engine. There 
are a number of Audio IF's that already have similar things in them, but 
they have not generally been controlable from Linux. This is MIDI 
controlable and the various control apps seem to use MIDI (over IP) to 
control the mixer. As I say, there are a lot of these kinds of apps around 
already and at least some of them are open source.

Note: Maybe not, see below after I did some more reading. The X32 linux 
edit/controler release notes say it uses OSC. The X Air release notes do 
not say anything at all. Neither application comes with any manual at 
all... But, After running and playing around with these apps and 
restarting them I noticed that changes I had made on first run were still 
there... On further investigation, I found ~/.X18-Edit.init and the 
contents look a lot like OSC commands (ch/01/mix ON  -5.4 ON +0 - this is 
with the fader at -5.4)

The manual does include the MIDI implementation. Everything is CC 
controled (HUI/MCP uses notes, pitch wheel and cc) Faders are 7 bit 
(0-127). There is something called X OSC which is done via sysex They say 
"text based OSC". There is no mention of metering at all.

After Downloading and running the X air Linux mixer app, I am not sure it 
uses the MIDI in the chart. There is nothing that says what it does do but 
after reading the X32 stuff, it may be OSC. The mixer app does include 
everything, much more than the MIDI implementation shows.


> If I understand everything right the X32 can be connected to a Linux PC and 
> then the channels are discovered by Alsa and can be used by Jack. Have anyone 
> here tested the X Air series?

It (X AIR) is a class compliant USB2 IF. I am guessing that if they have 
"Linux" listed they have tested it. It is interesting that win is listed as:
Windows 7 or higher
Apple:
Mac OSX 10.6.8 or higher/iOS 7 or higher
Linux is just:
Linux

The X32 mixer has no mention of Linux in the manual and the mention of the 
Linux/Android controllers is at the bottom of the web page as well (with 
the windows control app) while the older copy farther up mentions only OSX 
and iOS. So the Linux app is something new. The release notes for the X32 
say it uses OSC for commumication. The MIDI setup seem to be the first 8 
channels only in HUI/MCP/cc modes, plus whatever controls have "learned". 
So the MIDI part on this one is to allow the mixer to be used as a control 
surface. It does not look like MIDI controls the rest of the mixer. The 
Linux edit control does not come with a manual (runs ok though) and the 
OSC commands are not given... I imagine an OSC monitor could pick them up 
pretty quick though. (I think the OSC commands are in the *init files)

The two apps are worth downloading just to see how they are put together 
and to see the different ways they have of presenting the same data.


--
Len Ovens
www.ovenwerks.net