MOTU channels not corresponding properly with dac~ channels
I'm working on a 3D spatialized installation using 6 speakers and the ICST ambisonics package. The setup wasn't behaving exactly as expected when moving the location of the sound around, and in troubleshooting we found that channels 1 and 2 from the dac~ object weren't actually outputting any sound — only channels 3, 4, 5, and 6. We have the computer hooked up to a MOTU ultra-lite hybrid and the 6 speakers are connected to main output left, main output right, analog output 1, analog output 2, analog output 3, and analog output 4. By unplugging all but one speaker and changing the output it was plugged into we found that these outputs were playing the dac~ channels 3, 4, 3, 4, 5, 6 respectively. So the question is... how do we get the main left and right outputs to play channels 1 and 2 from the dac~ as expected? Even when experimenting with an ezdac~ object with only 2 channels no sound was output from the MOTU at all. Hopefully this is a clear explanation. Please let me know if anything could use some clarifying!
Cheers,
Jake
Max does not know about audio channels, their order or which interface provides them. It doesn't even know if audio channels exist or not.
You may check a couple of things on the way from source to target.
Max/MSP:
Routing failure before the dac~
Numbering (arguments) of the dac~ channels
Options>Audio Status: Driver, Devices, Input, Output, I/O Mapping
In the "Extras" Menu you find a "Meter Out" panel, maybe helpful.
Close Max, re-open, fresh (and only) patcher with just the main outputs. Same behavior?
Computer, if you are on a Mac:
System Preferences "Sound" (selected output)
"Audio MIDI Setup" – Aggregate Devices may change the channel order.
Other routing you may use (DAW, Soundflower, Jack, Hosting AU, AULab etc)
Computer if you are on a PC:
Don't know
Interface:
Internal MOTU routing (I don't know this interface)
As first, Max does know how many Audio Channels one Audio Interface provides,
and fills menues in I/O mappings accordingly.
Linking Max dac~ 1 2 3 4 5 6 etc to Interface Outputs can be a bit confusing
because one can configure Audio Interface for example to use Optical Inputs as ADAT
or SPDIF, which would shift all Output Numberings, or set Phones to reflect Main
Outputs or act as separate 2 Channels.
Motu usually has Main Outs as 1 &2, followed by Analog Outputs 1 2 3 4 5 6 etc,
then Phones, and at the end Digital ones, but that migh vary from interface to interface.
So I would suggest to first set all Max dac~ outs to default 1 : 1, 2 : 2 etc and then send audio
to each channel separately to see where it is going.
One can simply send set message to {dac~ 1 2} to change the channel number.
And I would do it without any surround externals, just a plain audio out.
Well, my Max (actually not Max but the whole audio system of the Mac) does seldom know much about audio channels. I often work with more than one interface and with and without Soundflower or Hosting AU. When I change the setup, I take a DAW or Max and test signals to find out which input/output numbers carry which signals.
When I have routing problems like Jake, the bug sits usually in front of the monitor (me) and my favored failures are wrong device selection, I/O mapping, virtual routing outside of Max and wrong routing in the interface(s). Don't know it that helps. But at least I've never seen a problem with Max in/out channels; wrong routing happened always somewhere else.
Hey Jake,
I have Max 7 and also a MOTU Ultralight hybrid on a Mac. Try this, first go to Audio Midi setup application. Look in the audio window. At the bottom of the window is a "configure speakers" button, click on that. In the next dialog box make sure that "main out has 2 channels (1-2)" is clicked. Maybe you want to click "analog has 8 channels 3-10) " clicked too, but i don't.
Also, in the MOTU application that comes with the interface is software called "MOTU Audio Setup." Open that up and make sure Default Stereo Output is Main Out 1-2. That should help. If it doesn't try messing with MOTU Audio Setup. I had to configure it to my liking at first but now it works great. I hope this helps.
Nick
Thank you all for your advice! We've tried all those things but couldn't get the main left and right to output differently than the analog 3-4, so alas, we settled on the less than elegant solution of mapping all outputs to analog channels 5-10, which gave us 6, unique, functioning channels. Still seems very strange that we couldn't get the main left and right working properly... Wonder if it was an issue in the hardware or the software?
It is hard to think about answer, not knowing what Operating System is in use, what is set up in Motu Audio Setup
or Cue Mix FX.