it cant see such pcm

speaker-test -c 2 -t wav -d -D surround21:0

speaker-test 1.0.27.2

Playback device is surround21:0
Stream parameters are 48000Hz, S16_LE, 2 channels
WAV file(s)
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM surround21:0
Playback open error: -2,No such file or directory



aplay -L
null
    Discard all samples (playback) or generate zero samples (capture)
pulse
    PulseAudio Sound Server
default
    Playback/recording through the PulseAudio sound server
sysdefault:CARD=PCH
    HDA Intel PCH, ALC663 Analog
    Default Audio Device
front:CARD=PCH,DEV=0
    HDA Intel PCH, ALC663 Analog
    Front speakers
surround40:CARD=PCH,DEV=0
    HDA Intel PCH, ALC663 Analog
    4.0 Surround output to Front and Rear speakers
surround41:CARD=PCH,DEV=0
    HDA Intel PCH, ALC663 Analog
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=PCH,DEV=0
    HDA Intel PCH, ALC663 Analog
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=PCH,DEV=0
    HDA Intel PCH, ALC663 Analog
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=PCH,DEV=0
    HDA Intel PCH, ALC663 Analog
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=PCH,DEV=0
    HDA Intel PCH, ALC663 Digital
    IEC958 (S/PDIF) Digital Audio Output
dmix:CARD=PCH,DEV=0
    HDA Intel PCH, ALC663 Analog
    Direct sample mixing device
dmix:CARD=PCH,DEV=1
    HDA Intel PCH, ALC663 Digital
    Direct sample mixing device
dsnoop:CARD=PCH,DEV=0
    HDA Intel PCH, ALC663 Analog
    Direct sample snooping device
dsnoop:CARD=PCH,DEV=1
    HDA Intel PCH, ALC663 Digital
    Direct sample snooping device
hw:CARD=PCH,DEV=0
    HDA Intel PCH, ALC663 Analog
    Direct hardware device without any conversions
hw:CARD=PCH,DEV=1
    HDA Intel PCH, ALC663 Digital
    Direct hardware device without any conversions
plughw:CARD=PCH,DEV=0
    HDA Intel PCH, ALC663 Analog
    Hardware device with all software conversions
plughw:CARD=PCH,DEV=1
    HDA Intel PCH, ALC663 Digital
    Hardware device with all software conversions



in pulseaudio i have 2.1 profile

here is the output of default pcm  (in pulse 2.1 profile is set)  -- pulse have enable lfe remixing in conf set to yes


speaker-test -c 2 -t wav -d

speaker-test 1.0.27.2

Playback device is default
Stream parameters are 48000Hz, S16_LE, 2 channels
WAV file(s)
Rate set to 48000Hz (requested 48000Hz)
Buffer size range from 96 to 1048576
Period size range from 32 to 349526
Using max buffer size 1048576
Periods = 4
was set period_size = 262144
was set buffer_size = 1048576
ALSA <-> PulseAudio PCM I/O Plugin
Its setup is:
  stream       : PLAYBACK
  access       : RW_INTERLEAVED
  format       : S16_LE
  subformat    : STD
  channels     : 2
  rate         : 48000
  exact rate   : 48000 (48000/1)
  msbits       : 16
  buffer_size  : 1048576
  period_size  : 262144
  period_time  : 5461333
  tstamp_mode  : NONE
  period_step  : 1
  avail_min    : 262144
  period_event : 0
  start_threshold  : 1048576
  stop_threshold   : 1048576
  silence_threshold: 0
  silence_size : 0
  boundary     : 4611686018427387904
 0 - Front Left
 1 - Front Right
Time per period = 3,032548
 0 - Front Left
 1 - Front Right



both front-left / front-right  can be heard from subwoofer