How to Configure ALSA in Ubuntu 16.04 for Macbook and Matlab?

Situation: unable to configure ALSA in Ubuntu 16.04 for Matlab 2016a
System characteristics

• /proc/asound/cards

    0 [HDMI           ]: HDA-Intel - HDA Intel HDMI
                         HDA Intel HDMI at 0xb0a10000 irq 54
    1 [PCH            ]: HDA-Intel - HDA Intel PCH
                         HDA Intel PCH at 0xb0a14000 irq 53
  

• /usr/share/alsa/also.conf found here where I tried the following at the end of the file unsuccessfully because I think device 1 is my sound thing (PCH)

    pcm.!default {
     type hw
     card 0
     device 1
    }
  

Test code in Matlab

soundsc(230)

Errors

ALSA lib pcm_dsnoop.c:606:(snd_pcm_dsnoop_open) unable to open slave
ALSA lib pcm_dmix.c:1029:(snd_pcm_dmix_open) unable to open slave
ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2266:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
ALSA lib pcm_dmix.c:1029:(snd_pcm_dmix_open) unable to open slave

Manual proposal

I found one possible proposal in the blog post PyAudio, PortAudio, and ALSA messages which says

• remove the line pcm.rear cards.pcm.rear in /usr/share/alsa/alsa.conf.
• Have snd_lib_error_set_handler() of alsa-lib to set a new error handler instead of default one; How to do this?

Unsuccessful Attempt by following Monkeyman_stones' Piece of Advice

I follow instructions for the older Macbook Air which still uses the same/similar sound chip in the wikipage MacBookAir3-2/Meerkat > Sound. I do unsuccessfully

1. Terminal, sudo vim /etc/modprobe.d/alsa-base.conf and add the line options snd-hda-intel model=mba31 to the end of the file.
2. Terminal, alsamixer and use arrow keys to select Front Speaker (testing S/PDIF, S/PDIF 1 and S/PDIF 2) and press mand last ESC. Done!
3. Output: Same warnings as before after running any code in Matlab prompt. After reboot, the system forgets all changes in alsamixer. I tried also with sudo alsamixer. How can you make those changes permanent?

My complete /etc/modprobe.d/alsa-base.conf after the change and you cannot see there duplicates of snd-hda-intel, only once, which does not seem to affect alsamixer at all

install sound-slot-0 /sbin/modprobe snd-card-0
install sound-slot-1 /sbin/modprobe snd-card-1
install sound-slot-2 /sbin/modprobe snd-card-2
install sound-slot-3 /sbin/modprobe snd-card-3
install sound-slot-4 /sbin/modprobe snd-card-4
install sound-slot-5 /sbin/modprobe snd-card-5
install sound-slot-6 /sbin/modprobe snd-card-6
install sound-slot-7 /sbin/modprobe snd-card-7

# Cause optional modules to be loaded above generic modules
install snd /sbin/modprobe --ignore-install snd $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-ioctl32 ; /sbin/modprobe --quiet --use-blacklist snd-seq ; }
#
# Workaround at bug #499695 (reverted in Ubuntu see LP #319505)
install snd-pcm /sbin/modprobe --ignore-install snd-pcm $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-pcm-oss ; : ; }
install snd-mixer /sbin/modprobe --ignore-install snd-mixer $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-mixer-oss ; : ; }
install snd-seq /sbin/modprobe --ignore-install snd-seq $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-seq-midi ; /sbin/modprobe --quiet --use-blacklist snd-seq-oss ; : ; }
#
install snd-rawmidi /sbin/modprobe --ignore-install snd-rawmidi $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-seq-midi ; : ; }
# Cause optional modules to be loaded above sound card driver modules
install snd-emu10k1 /sbin/modprobe --ignore-install snd-emu10k1 $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-emu10k1-synth ; }
install snd-via82xx /sbin/modprobe --ignore-install snd-via82xx $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-seq ; }

# Load saa7134-alsa instead of saa7134 (which gets dragged in by it anyway)
install saa7134 /sbin/modprobe --ignore-install saa7134 $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist saa7134-alsa ; : ; }
# Prevent abnormal drivers from grabbing index 0
options bt87x index=-2
options cx88_alsa index=-2
options saa7134-alsa index=-2
options snd-atiixp-modem index=-2
options snd-intel8x0m index=-2
options snd-via82xx-modem index=-2
options snd-usb-audio index=-2
options snd-usb-caiaq index=-2
options snd-usb-ua101 index=-2
options snd-usb-us122l index=-2
options snd-usb-usx2y index=-2
# Ubuntu #62691, enable MPU for snd-cmipci
options snd-cmipci mpu_port=0x330 fm_port=0x388
# Keep snd-pcsp from being loaded as first soundcard
options snd-pcsp index=-2
# Keep snd-usb-audio from beeing loaded as first soundcard
options snd-usb-audio index=-2

# https://help.ubuntu.com/community/MacBookAir3-2/Meerkat
# Start up a terminal, run alsamixer and use arrow keys to select Front Speaker and press m, then all is good sound-wise.
# TODO this is not affecting `alxamixer` at all; restart restores the defaults. Why?
options snd-hda-intel model=mba31

Official Matlab docs about sounds in Linux: ALSA Audio Playback
Related threads: No sound with HDA Intel PCH, Alsa problems with python2.7- Unable to open slave, Why ALSA lib is not working in Ubuntu?

Solution 1:

While this says that it's targeted for Ubuntu Meerkat (10.10), Alsa-base.conf settings have not changed much at all, so the directions are still sound: Ubuntu directions for sound from the early Macbook Air

As it uses an HDA Intel sound card type, changes specific to your device's sound card settings in /etc/modprobe.d/alsa-base.conf are required.