Comment 18 for bug 1805079

I am using an X1 Carbon Gen 6 (BIOS 1.31) with Ubuntu 18.04.1 LTS, and I too experience the popping sounds in the left-channel of my headphones (this does not occur when connecting the same headphones with a 3.5mm-to-USB-C adapter to the second USB-C port).

Other than that issue, audio through the headphones sounds great and can get very loud (I typically cannot go above 58%), but audio through the speakers can get tinny/distorted and is quiet at 100%. I believe this is a known issue with the X1 Carbon's speakers and is probably unrelated to the issue at hand, but I thought it is worth mentioning since there is discussion in this thread about using the speaker's DAC for the headphones instead of the headphone's DAC.

I applied the changes mentioned here [1], and the popping sounds in the left-channel of my headphones appear to have stopped. I have been using this video [2] to test before and after the changes due to its wide range of audio and vocals (quiet, normal, and loud moments).

alsa-info: http://www.alsa-project.org/db/?f=d961cfbf429bc18b38ce8d1cf8e931482ba4a627

[1] https://forums.lenovo.com/t5/Linux-Discussion/X1-Carbon-Gen-6-weird-audio-behaviour/m-p/4172468/highlight/true#M11520

[2] https://youtu.be/f2kesmAO8VU