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Split stereo channels over two simultaneous usb audio devices? - Printable Version

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Split stereo channels over two simultaneous usb audio devices? - micindev - 02-Dec-2020

so i ended up with two amazon echo studios and i have no use for a wireless speakers - gift Undecided  both have a toslink input, but they are unable to play in stereo wired - channels have to splitted before.

is there a possibility to send left channel to one usb port, and right channel to second usb port?

thanks
-um

RE: Split stereo channels over two simultaneous usb audio devices? - agent_kith - 03-Dec-2020

(02-Dec-2020, 11:44 PM)micindev Wrote: so i ended up with two amazon echo studios and i have no use for a wireless speakers - gift Undecided  both have a toslink input, but they are unable to play in stereo wired - channels have to splitted before.

is there a possibility to send left channel to one usb port, and right channel to second usb port?

thanks
-um
jackd might do it, but I'm not too sure if it can route mono signals to seperate audio cards.

Easier solution is to just get two ADCs (Analog to digital convertors), connect LCH to one, and RCH to another, and then optical cable to your echos. Although it's easy, quality may be a bit iffy as there could be phase differences (i.e. left and right channels may not be exactly in sync). However, because you are using echos, this difference is unlikely to be discernable.

RE: Split stereo channels over two simultaneous usb audio devices? - micindev - 03-Dec-2020

(03-Dec-2020, 07:23 AM)agent_kith Wrote:
(02-Dec-2020, 11:44 PM)micindev Wrote: so i ended up with two amazon echo studios and i have no use for a wireless speakers - gift Undecided  both have a toslink input, but they are unable to play in stereo wired - channels have to splitted before.

is there a possibility to send left channel to one usb port, and right channel to second usb port?

thanks
-um
jackd might do it, but I'm not too sure if it can route mono signals to seperate audio cards.

Easier solution is to just get two ADCs (Analog to digital convertors), connect LCH to one, and RCH to another, and then optical cable to your echos. Although it's easy, quality may be a bit iffy as there could be phase differences (i.e. left and right channels may not be exactly in sync). However, because you are using echos, this difference is unlikely to be discernable.

thanks for reply

ah, ok... I thought it would be a simple line of code, somewhere someone said that alsa should be able to do it, but coding is beyond my abilities. I planned basic kitchen stereo synced with other rooms and I wanted to keep echo's dsp...

just found this article, not sure if it makes any sense... https://bootlin.com/blog/audio-multi-channel-routing-and-mixing-using-alsalib/

RE: Split stereo channels over two simultaneous usb audio devices? - agent_kith - 04-Dec-2020

(03-Dec-2020, 07:10 PM)micindev Wrote: just found this article, not sure if it makes any sense... https://bootlin.com/blog/audio-multi-channel-routing-and-mixing-using-alsalib/
That might work, uses something call dshare instead of jack. Not entirely sure if Snakeoil currently works on special ALSA configurations as it's more or less hard coded to work only on direct audio cards (HW)...

This is something that is certainly going to be improved in Snakeoil down the road.

RE: Split stereo channels over two simultaneous usb audio devices? - micindev - 08-Dec-2020

(04-Dec-2020, 07:54 AM)agent_kith Wrote:
(03-Dec-2020, 07:10 PM)micindev Wrote: just found this article, not sure if it makes any sense... https://bootlin.com/blog/audio-multi-channel-routing-and-mixing-using-alsalib/
That might work, uses something call dshare instead of jack. Not entirely sure if Snakeoil currently works on special ALSA configurations as it's more or less hard coded to work only on direct audio cards (HW)...

This is something that is certainly going to be improved in Snakeoil down the road.

Interesting... Thanks for the reply, maybe I keep echoes than and just wait

RE: Split stereo channels over two simultaneous usb audio devices? - Snoopy8 - 08-Dec-2020

Am I missing something here?  I believe the Amazon Echo Studio can be set up as a wireless stereo pair. Why not use them as such?

Instead, the proposal is to make them as 2 active speakers which needs:
  • a custom ALSA coding to split a stereo signal into separate left and right channels; this may or may not work?
  • Sending left and right channels to 2 separate USB ports, and assume that the 2 USB ports remain in synch
  • Converting USB output to optical; requires 2 USB cables & 2 optical cables plus 2 converters

A lot of effort with a complicated setup, which may or may not work...  Not sure this is a good idea?

RE: Split stereo channels over two simultaneous usb audio devices? - Snoopy8 - 09-Dec-2020

Can this work with the Amazon Echo Studio?  This is based on what I can do with Sonos and I am assuming the Amazon Echo Studio (which I do not own) has the same capabilities, including UPnP/DLNA.
  1. Set up units with wifi and phone app
  2. Create stereo pair with phone app and check using music from phone
  3. In SnakeOil, start up LMS
  4. Enable UPnP/DLNA Bridge plugin and restart LMS
  5. After a few minutes, the stereo pair should show up as a player in LMS; you can now play music from SnakeOil to the units


RE: Split stereo channels over two simultaneous usb audio devices? - micindev - 15-Dec-2020

(09-Dec-2020, 05:55 PM)Snoopy8 Wrote: Can this work with the Amazon Echo Studio?  This is based on what I can do with Sonos and I am assuming the Amazon Echo Studio (which I do not own) has the same capabilities, including UPnP/DLNA.
  1. Set up units with wifi and phone app
  2. Create stereo pair with phone app and check using music from phone
  3. In SnakeOil, start up LMS
  4. Enable UPnP/DLNA Bridge plugin and restart LMS
  5. After a few minutes, the stereo pair should show up as a player in LMS; you can now play music from SnakeOil to the units

wow! what a great idea! I was sure that amazon use some kind of proprietary protocol and i never even tried this solution... thanks