Thinkpad X1 Carbon sound is still tinny

[Dan Gillmor]

This is not a new issue, and despite the fix reported in https://bugs.launchpad.net/ubuntu/+source/alsa-ucm-conf/+bug/1872108 the sound remains thin and lacking bass in Thinkpad X1 Carbon models up to and including the latest generations.

Hoping that this will be dealt with eventually, but definitely not holding my breath. (I've had this issue on X1 Carbon Generation 7, 9, and now 11.

Running Ubuntu 22.04.3
alsa-ucm-conf:
  Installed: 1.2.6.3-1ubuntu1.7
  Candidate: 1.2.6.3-1ubuntu1.7
  Version table:
 *** 1.2.6.3-1ubuntu1.7 500
        500 http://jp.archive.ubuntu.com/ubuntu jammy-updates/main amd64 Packages
        500 http://jp.archive.ubuntu.com/ubuntu jammy-updates/main i386 Packages
        100 /var/lib/dpkg/status
     1.2.6.3-1ubuntu1 500
        500 http://jp.archive.ubuntu.com/ubuntu jammy/main amd64 Packages
        500 http://jp.archive.ubuntu.com/ubuntu jammy/main i386 Packages

What I expect: Sound from all speakers including some bass
What happens: Very thin, tinny sound, no bass.