Just some notes around the Sony WH-1000XM2

• pro: wireless: bluetooth profiles for headset and High Fidelity playback (A2DP)
• pro: quite good noise cancelling
• pro: build in rechargable battery
• con: when the cable is used, only headphone functionality is available. No microphone signal goes over the analog cable.
• con: after 60min of wearing, I need to take the headset off

bluetooth profiles supported by the headset:

• Advanced Audio Distribution Profile (A2DP)
• Hands Free (HFP)
• Headphones (HSP)
• Audio/Video Remote Control Profile (AVRCP)
• BTLE (Bluetooth Low Energy)

One can choose between pure Audio output (A2DP profile) in good quality, or hearing/listening (HFP/HSP profile) with lower quality. HFP in version 1.6 seems to also support better audio transport. The bluez5 implementation on Linux seems to support HFP v1.6 and HSP v1.2 (reference). Not sure how to see which version is used for communication with the headset.

“Hands-Free Profile (HFP) Version 1.6 adds optional support for wide band speech with the mSBC codec, a 16 kHz monaural configuration of the SBC codec mandated by the A2DP profile.”

# get the card index
CARDINDEX=$(pacmd list-cards | grep index|tail -1|awk '{print $2}')
echo $CARDINDEX
pacmd set-card-profile $CARDINDEX a2dp_sink
#     set-card-profile $CARDINDEX headset_head_unit
pacmd list-cards|grep active|tail -1

On Fedora31 and later, these profiles became available:

headset_head_unit: Headset Head Unit (HSP/HFP) (priority 30, available: unknown)
a2dp_sink_sbc: High Fidelity Playback (A2DP Sink: SBC) (priority 40, available: unknown)
a2dp_sink_aac: High Fidelity Playback (A2DP Sink: AAC) (priority 40, available: unknown)
a2dp_sink_aptx: High Fidelity Playback (A2DP Sink: aptX) (priority 40, available: unknown)
a2dp_sink_aptx_hd: High Fidelity Playback (A2DP Sink: aptX HD) (priority 40, available: yes)
a2dp_sink_ldac: High Fidelity Playback (A2DP Sink: LDAC) (priority 40, available: unknown)

# Let's install the required packages.  Pulls in pulseaudio.
# Before these codecs became available, package 
# pulseaudio-module-bluetooth got installed instead.
[root@спутник ~]# dnf install pulseaudio-module-bluetooth-freeworld
  
# Now restart pulseaudio.  Typically, one daemon is running
# on your system.  Execute the following as user, not root.
[chris@спутник ~]$ killall pulseaudio
[chris@спутник ~]$ pulseaudio --start

[root@спутник ~]# systemctl status bluetooth.service

[chris@спутник ~]$ bluetoothctl 
Agent registered
[CHG] Controller XX:XX:XX:XX:XX:B7 Pairable: yes
[LE_WH-1000XM2]# scan on
Discovery started
[CHG] Controller XX:XX:XX:XX:XX:B7 Discovering: yes
[CHG] Device XX:XX:XX:XX:XX:85 RSSI: -48
[CHG] Device XX:XX:XX:XX:XX:85 TxPower: 4
[CHG] Device XX:XX:XX:XX:XX:85 Name: WH-1000XM2
[CHG] Device XX:XX:XX:XX:XX:85 Alias: WH-1000XM2
[NEW] Device XX:XX:XX:XX:XX:6D XX:XX:XX:XX:XX:6D
[LE_WH-1000XM2]#  trust XX:XX:XX:XX:XX:85
Changing XX:XX:XX:XX:XX:85 trust succeeded
[LE_WH-1000XM2]# connect XX:XX:XX:XX:XX:85
Attempting to connect to XX:XX:XX:XX:XX:85
Connection successful
[CHG] Device XX:XX:XX:XX:XX:85 RSSI: -59
[CHG] Device XX:XX:XX:XX:XX:85 Name: LE_WH-1000XM2

$ sudo bluetoothctl
[bluetooth]# power on
[bluetooth]# agent on
[bluetooth]# default-agent
[bluetooth]# scan on
[NEW] Device XX:XX:XX:XX:XX:XX WH-1000XM2
[bluetooth]# scan off
[bluetooth]# trust XX:XX:XX:XX:XX:XX
[bluetooth]# pair XX:XX:XX:XX:XX:XX
Attempting to pair with XX:XX:XX:XX:XX:XX
[CHG] Device XX:XX:XX:XX:XX:XX Connected: yes
[CHG] Device XX:XX:XX:XX:XX:XX UUIDs: ... 
[CHG] Device XX:XX:XX:XX:XX:XX UUIDs: ... 
[CHG] Device XX:XX:XX:XX:XX:XX UUIDs: ... 
[CHG] Device XX:XX:XX:XX:XX:XX UUIDs: ... 
[CHG] Device XX:XX:XX:XX:XX:XX UUIDs: ... 
[CHG] Device XX:XX:XX:XX:XX:XX UUIDs: ... 
[CHG] Device XX:XX:XX:XX:XX:XX UUIDs: ... 
[CHG] Device XX:XX:XX:XX:XX:XX UUIDs: ... 
[CHG] Device XX:XX:XX:XX:XX:XX Paired: yes
Pairing successful
[CHG] Device XX:XX:XX:XX:XX:XX Connected: no
[bluetooth]# connect XX:XX:XX:XX:XX:XX
Attempting to connect to XX:XX:XX:XX:XX:XX
[CHG] Device XX:XX:XX:XX:XX:XX Connected: yes
Connection successful
[bluetooth]# quit

• youtube: the Luigi headphone test
• Queen - Bohemian Rhapsody - AUDIO 3DD
• LineageOS implements now SBC XQ, comparable to aptX and aptX HD

• 'blueman-applet' says when trying to connect to the headset “protocol not available.
• bluetoothctl reports this:

[chris@電脳 ~]$ bluetoothctl
Agent registered
[CHG] Controller 34:E1:2D:7C:61:B7 Pairable: yes
[bluetooth]# scan on
Discovery started
[CHG] Controller 34:E1:2D:7C:61:B7 Discovering: yes
[..]
[CHG] Device 70:26:05:9D:31:85 Name: LE_WH-1000XM2
[CHG] Device 70:26:05:9D:31:85 Alias: LE_WH-1000XM2
[bluetooth]# trust 70:26:05:9D:31:85
Changing 70:26:05:9D:31:85 trust succeeded
[NEW] Device 4D:E9:CA:BF:05:3B 4D-E9-CA-BF-05-3B
[bluetooth]# connect 70:26:05:9D:31:85
Attempting to connect to 70:26:05:9D:31:85
Failed to connect: org.bluez.Error.Failed

• When trying to connect in 'blueman-applet', error “unknown protocol” appears, and “systemctl status bluetooth.service” reports:

bluetoothd[23]: src/service.c:btd_service_connect() a2dp-sink profile connect failed for 70:26:05:9D:31:85: Protocol not available
bluetoothd[23]: src/service.c:btd_service_connect() a2dp-sink profile connect failed for 70:26:05:9D:31:85: Protocol not available

• Ensure package pulseaudio-module-bluetooth-freeworld or pulseaudio-module-bluetooth is installed.
• If you installed the package after starting pulseaudio or your Xorg session, then do this as user:

killall pulseaudio
pulseaudio --start