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System configuration:

  • Thinkpad X1 Carbon 5th Gen.
  • Ubuntu 18.10
  • Sound card: Intel Corporation Sunrise Point-LP HD Audio, CX8200
  • Kernel: 4.18.0-15-generic

The problem:

When playing audio (any source, Youtube, Spotify etc...) , audio sounds well at first (can be for many minutes, sometimes an hour) and all of a sudden the sound becomes metallic, distant, garbled and distorted. This happens on my headphones connected directly to the laptop or playing through the Thinkpad USB-C Dock, playing directly through the speakers is not an option since I'm in an open space office.

I tried the following without success:

  • Modify default.pa/system.pa with: load-module module-udev-detect tsched=0
  • Tried to play directly on Alsa without pulseaudio
  • Tried to play with the volume up and down etc ... (sometimes it helps but then get screwed up again after a while)
  • Tried to modify the sample rates in daemon.conf to other values.

Restart helps but again the sound gets distorted after few minutes. It makes my audio listening completely useless on this hardware. And generally speaking, the whole audio experience as compared with Windows is much much less robust :(

Some queries on my system:

root:~# uname -r
4.18.0-15-generic

root:~# dmesg | grep audio
[    3.250359] snd_hda_intel 0000:00:1f.3: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915])
[    3.351782] snd_hda_codec_conexant hdaudioC0D0: CX8200: BIOS auto-probing.
[    3.352919] snd_hda_codec_conexant hdaudioC0D0: autoconfig for CX8200: line_outs=1 (0x17/0x0/0x0/0x0/0x0) type:speaker
[    3.352921] snd_hda_codec_conexant hdaudioC0D0:    speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
[    3.352923] snd_hda_codec_conexant hdaudioC0D0:    hp_outs=1 (0x16/0x0/0x0/0x0/0x0)
[    3.352924] snd_hda_codec_conexant hdaudioC0D0:    mono: mono_out=0x0
[    3.352925] snd_hda_codec_conexant hdaudioC0D0:    inputs:
[    3.352927] snd_hda_codec_conexant hdaudioC0D0:      Internal Mic=0x1a
[    3.352929] snd_hda_codec_conexant hdaudioC0D0:      Mic=0x19
[    3.356819] snd_hda_codec_conexant hdaudioC0D0: Enable sync_write for stable communication
[    5.292555] usbcore: registered new interface driver snd-usb-audio

root:~# lspci -v | grep -i audio
00:1f.3 Audio device: Intel Corporation Sunrise Point-LP HD Audio (rev 21)
    Subsystem: Lenovo Sunrise Point-LP HD Audio

    root:~# pacmd list-sinks
2 sink(s) available.
  * index: 0
    name: <alsa_output.usb-Lenovo_ThinkPad_USB-C_Dock_Audio_000000000000-00.analog-stereo>
    driver: <module-alsa-card.c>
    flags: HARDWARE HW_MUTE_CTRL HW_VOLUME_CTRL LATENCY 
    state: IDLE
    suspend cause: (none)
    priority: 9049
    volume: front-left: 11106 /  17%,   front-right: 11106 /  17%
            balance 0.00
    base volume: 65536 / 100%
    volume steps: 51
    muted: no
    current latency: 102.52 ms
    max request: 18 KiB
    max rewind: 18 KiB
    monitor source: 0
    sample spec: s16le 2ch 48000Hz
    channel map: front-left,front-right
                 Stereo
    used by: 0
    linked by: 1
    fixed latency: 100.00 ms
    card: 0 <alsa_card.usb-Lenovo_ThinkPad_USB-C_Dock_Audio_000000000000-00>
    module: 7
    properties:
        alsa.resolution_bits = "16"
        device.api = "alsa"
        device.class = "sound"
        alsa.class = "generic"
        alsa.subclass = "generic-mix"
        alsa.name = "USB Audio"
        alsa.id = "USB Audio"
        alsa.subdevice = "0"
        alsa.subdevice_name = "subdevice #0"
        alsa.device = "0"
        alsa.card = "1"
        alsa.card_name = "ThinkPad USB-C Dock Audio"
        alsa.long_card_name = "Lenovo ThinkPad USB-C Dock Audio at usb-0000:3c:00.0-1.4.2.3, full speed"
        alsa.driver_name = "snd_usb_audio"
        device.bus_path = "pci-0000:3c:00.0-usb-0:1.4.2.3:1.0"
        sysfs.path = "/devices/pci0000:00/0000:00:1d.0/0000:06:00.0/0000:07:02.0/0000:3c:00.0/usb3/3-1/3-1.4/3-1.4.2/3-1.4.2.3/3-1.4.2.3:1.0/sound/card1"
        udev.id = "usb-Lenovo_ThinkPad_USB-C_Dock_Audio_000000000000-00"
        device.bus = "usb"
        device.vendor.id = "17ef"
        device.vendor.name = "Lenovo"
        device.product.id = "3063"
        device.product.name = "ThinkPad USB-C Dock Audio"
        device.serial = "Lenovo_ThinkPad_USB-C_Dock_Audio_000000000000"
        device.string = "front:1"
        device.buffering.buffer_size = "19200"
        device.buffering.fragment_size = "4800"
        device.access_mode = "mmap"
        device.profile.name = "analog-stereo"
        device.profile.description = "Analog Stereo"
        device.description = "ThinkPad USB-C Dock Audio Analog Stereo"
        alsa.mixer_name = "USB Mixer"
        alsa.components = "USB17ef:3063"
        module-udev-detect.discovered = "1"
        device.icon_name = "audio-card-usb"
    ports:
        analog-output: Analog Output (priority 9900, latency offset 0 usec, available: unknown)
            properties:

    active port: <analog-output>
    index: 1
    name: <alsa_output.pci-0000_00_1f.3.analog-stereo>
    driver: <module-alsa-card.c>
    flags: HARDWARE HW_MUTE_CTRL HW_VOLUME_CTRL LATENCY 
    state: RUNNING
    suspend cause: (none)
    priority: 9039
    volume: front-left: 63624 /  97%,   front-right: 63624 /  97%
            balance 0.00
    base volume: 65536 / 100%
    volume steps: 75
    muted: no
    current latency: 100.90 ms
    max request: 18 KiB
    max rewind: 18 KiB
    monitor source: 2
    sample spec: s16le 2ch 48000Hz
    channel map: front-left,front-right
                 Stereo
    used by: 1
    linked by: 3
    fixed latency: 100.00 ms
    card: 1 <alsa_card.pci-0000_00_1f.3>
    module: 8
    properties:
        alsa.resolution_bits = "16"
        device.api = "alsa"
        device.class = "sound"
        alsa.class = "generic"
        alsa.subclass = "generic-mix"
        alsa.name = "CX8200 Analog"
        alsa.id = "CX8200 Analog"
        alsa.subdevice = "0"
        alsa.subdevice_name = "subdevice #0"
        alsa.device = "0"
        alsa.card = "0"
        alsa.card_name = "HDA Intel PCH"
        alsa.long_card_name = "HDA Intel PCH at 0xec340000 irq 134"
        alsa.driver_name = "snd_hda_intel"
        device.bus_path = "pci-0000:00:1f.3"
        sysfs.path = "/devices/pci0000:00/0000:00:1f.3/sound/card0"
        device.bus = "pci"
        device.vendor.id = "8086"
        device.vendor.name = "Intel Corporation"
        device.product.id = "9d71"
        device.product.name = "Sunrise Point-LP HD Audio"
        device.form_factor = "internal"
        device.string = "front:0"
        device.buffering.buffer_size = "19200"
        device.buffering.fragment_size = "4800"
        device.access_mode = "mmap"
        device.profile.name = "analog-stereo"
        device.profile.description = "Analog Stereo"
        device.description = "Built-in Audio Analog Stereo"
        alsa.mixer_name = "Conexant CX8200"
        alsa.components = "HDA:14f12008,17aa224f,00100103 HDA:8086280b,80860101,00100000"
        module-udev-detect.discovered = "1"
        device.icon_name = "audio-card-pci"
    ports:
        analog-output-speaker: Speakers (priority 10000, latency offset 0 usec, available: no)
            properties:
                device.icon_name = "audio-speakers"
        analog-output-headphones: Headphones (priority 9000, latency offset 0 usec, available: yes)
            properties:
                device.icon_name = "audio-headphones"
    active port: <analog-output-headphones>

I tried to look all over the internet but nothing.

Help!!! Anyone got a clue ?

1 Answer 1

0

Well, as far as stupidity goes - the problem was a physical malfunctioning cable connector of my headphones ! :) , So make sure to check the obvious first !!! After replacing the cable, everything returned to normal.

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