How do I split out a Multichannel Ouput into individual inputs and ouputs

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forgetso
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How do I split out a Multichannel Ouput into individual inputs and ouputs

Post by forgetso »

I have a Roland Studio Capture plugged into Ubuntu 4.15.0-128-generic and it registers in the sound controls as "Multichannel Output" and "Multichannel Input". I can hear system sounds and music but I can't select individual output channels or individual input channels. Input does not work at all - I can't hear myself speaking into the mic.

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I have tried the JACK Audio Connection Kit, which allowed me to get hear my input from the mic back through the studio capture:
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However, this stops the audio working in everything else. I cannot hear music etc. When I use Bitwig, it is somehow able to differentiate between the various inputs and outputs of the Studio Capture using ALSA. How does it do this? Do I need to write a custom ALSA configuration to split the inputs and ouputs? Or does it go further than that?

Thanks for reading.
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bluebell
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Re: How do I split out a Multichannel Ouput into individual inputs and ouputs

Post by bluebell »

That's probably not a multichannel problem but the old problem with co-existence of Pulseaudio and JACK. There are many solutions. Mine is http://marzen.de/Holger/pulseaudio_and_jack/

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kirjis
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Re: How do I split out a Multichannel Ouput into individual inputs and ouputs

Post by kirjis »

I can't unfortunately offer you a complete solution, but I recently wanted to map two of my audio interface's four outputs as one stereo out, because Pulseaudio thinks it is a 4.0 surround out (which for example puts all sounds coming from behind in games to the two "rear" channels, and I can't hear them), and this Archwiki page has lots of helpful examples: https://wiki.archlinux.org/index.php/Pu ... o/Examples

I found the solution to my problem there.

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forgetso
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Re: How do I split out a Multichannel Ouput into individual inputs and ouputs

Post by forgetso »

bluebell wrote: Wed Jan 27, 2021 11:47 am That's probably not a multichannel problem but the old problem with co-existence of Pulseaudio and JACK. There are many solutions. Mine is http://marzen.de/Holger/pulseaudio_and_jack/
So I've tried your suggestion of setting up jack playback and capture ports but I'm still unable to hear any sound. On the left hand side if the Jack connections panel, if I connect system capture_1 to system playback_1, I can hear myself talking into the mic via my USB sound card.

How can I also get it to send audio from applications?
kirjis wrote: Wed Jan 27, 2021 12:55 pm I can't unfortunately offer you a complete solution, but I recently wanted to map two of my audio interface's four outputs as one stereo out, because Pulseaudio thinks it is a 4.0 surround out (which for example puts all sounds coming from behind in games to the two "rear" channels, and I can't hear them), and this Archwiki page has lots of helpful examples: https://wiki.archlinux.org/index.php/Pu ... o/Examples

I found the solution to my problem there.
Thanks, I've tried this but still no joy.
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Re: How do I split out a Multichannel Ouput into individual inputs and ouputs

Post by kirjis »

One thing that occasionally still trips me up is that on the Pulseaudio side, the Jack sink output has to be selected if Jack is running. So if I have this situation:
scr_2021-01-28_14-30.png
scr_2021-01-28_14-30.png (38.82 KiB) Viewed 1399 times
...I can't hear anything. The selected output is my virtual stereo output for the Presonus (actual four outputs are on the left), and I should have the one on the right (Jack sink) selected. If Jack is not running, however, this is what I'll be using, and the Jack sink is not visible.

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forgetso
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Re: How do I split out a Multichannel Ouput into individual inputs and ouputs

Post by forgetso »

Thaks for the input kirjis. When I run QJackCtl I do not have a Jack sink option. How have you enabled jack_sink? .asoundrc or something?
forgetso
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Re: How do I split out a Multichannel Ouput into individual inputs and ouputs

Post by forgetso »

Omg, I got this working with your suggestion kirjis. I created input bridges in Ubuntu Studio and suddenly can hear music. Thanks a lot! :D :D :D

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