I have a test program that creates 35 separate pipelines, each terminated in an alsasink. If I leave the alsasink devices set to 'default', it manages to open 32 of them before running out of devices. If I set the device to 'plug:dmix', it opens one and the rest fail. These are independent alsasink elements, if that makes a difference.

I'm not sure why my default device isn't going through dmix in the first place, but never mind that.

I will attach my sample program. Run it with 35 .wav filenames on the command line. (Although just 2 should do fine.)

pipeline #0 (N=35) returned 2
  waiting for async state change...
    Dynamic pad created, linking wav parser to sink
  done waiting, got 1
0:00:00.143564000 10621 0x81bf008 WARN                  alsa pcm_hw.c:430:snd_pcm_hw_channel_info: alsalib error: SNDRV_PCM_IOCTL_CHANNEL_INFO failed: File descriptor in bad state
0:00:00.143825000 10621 0x81bf008 WARN                  alsa pcm_direct.c:1255:snd_pcm_direct_initialize_secondary_slave: alsalib error: unable to mmap channels
0:00:00.143964000 10621 0x81bf008 WARN                  alsa pcm_dmix.c:925:snd_pcm_dmix_open: alsalib error: unable to initialize slave
0:00:00.144200000 10621 0x81bf008 WARN                  alsa gstalsasink.c:625:gst_alsasink_open:<sfink> error: Playback open error on device 'plug:dmix': File descriptor in bad state
pipeline #1 (N=35) returned 0
  failed (or no preroll?), so throwing out /home/sfink/Content/sounds/apert.wav
0:00:00.146187000 10621 0x81bf008 WARN                  alsa pcm_hw.c:430:snd_pcm_hw_channel_info: alsalib error: SNDRV_PCM_IOCTL_CHANNEL_INFO failed: File descriptor in bad state
0:00:00.146415000 10621 0x81bf008 WARN                  alsa pcm_direct.c:1255:snd_pcm_direct_initialize_secondary_slave: alsalib error: unable to mmap channels
0:00:00.146553000 10621 0x81bf008 WARN                  alsa pcm_dmix.c:925:snd_pcm_dmix_open: alsalib error: unable to initialize slave
0:00:00.146791000 10621 0x81bf008 WARN                  alsa gstalsasink.c:625:gst_alsasink_open:<sfink> error: Playback open error on device 'plug:dmix': File descriptor in bad state
pipeline #2 (N=35) returned 0
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