Bug 201613

Summary: Distorted and robotic microphone input on ALC892
Product: Drivers Reporter: Luca Osvaldo M. (lukycrociato)
Component: Sound(ALSA)Assignee: Jaroslav Kysela (perex)
Status: NEW ---    
Severity: normal CC: alex32.com, at46n, kailang, lukycrociato, perex, tiwai, tphaster, web
Priority: P1    
Hardware: x86-64   
OS: Linux   
Kernel Version: Every kernel version I tried, currently on 4.18.0 Subsystem:
Regression: No Bisected commit-id:
Attachments: alsa-info
Recording showing the noise

Description Luca Osvaldo M. 2018-11-03 17:36:51 UTC 
Created attachment 279301 [details]
alsa-info

I always got this issue only on Linux, every distro I tried including Manjaro Linux, Debian, ubuntu had this problem.

Basically the microphone input sounds always distorted and "robotic" even on high pitch. In all the programs I tried.

Workarounds as listed on the ArchWiki ---> https://wiki.archlinux.org/index.php/PulseAudio/Troubleshooting#Microphone_crackling_with_Realtek_ALC892 have not changed anything.

Interesting thing though is that on FreeBSD this does not happen.

alsa-info on the attachments

Kernel version: Linux luky-MS-7A37 4.18.0-10-generic #11-Ubuntu SMP

alsa-version
Driver version:     k4.18.0-10-generic
Library version:    1.1.6
Utilities version:  1.1.6

Obviously this also happens on other kernels.
Comment 1 Luca Osvaldo M. 2018-11-27 17:14:54 UTC 
Created attachment 279675 [details]
Recording showing the noise
Comment 2 Luca Osvaldo M. 2018-12-19 13:05:23 UTC 
I may confirm that recording without pulseaudio using ffmpeg -alsa produces the same disturbed sound
Comment 3 Luca Osvaldo M. 2018-12-20 11:52:30 UTC 
Motherboard model is an MSI B350M AM4 for Ryzen CPU's
Comment 4 Luca Osvaldo M. 2018-12-25 23:07:42 UTC 
There are other people having the same issue on the same motherboard model
Comment 5 Luca Osvaldo M. 2019-01-03 23:18:24 UTC 
A partial workaround which doesn't completely fix the issue but improves things is the following:

Adding to /etc/pulse/default.pa, use_ucm=0 tsched=0 right after module-udev-detect 

and /etc/pulse/daemon

resample-method = src-sinc-best-quality
default-sample-format = s16le
default-fragment-size-msec=80
default-sample-rate = 48000


Don't know which what specific parameter improved this, because when I test each one of those singularly doesn't totally fix the problem. 

The best results I can obtain are with all those combined
Comment 6 Luca Osvaldo M. 2019-01-04 00:23:15 UTC 
Actually this workaround adds another problem, in games the sound is delayed...
Comment 7 Alex 2019-04-23 19:40:39 UTC 
I have the same problem with MSI B450 Tomahawk Motherboard
Comment 8 Axel 2019-08-13 13:06:28 UTC 
IMHO this bug is could be closed because of https://bugzilla.kernel.org/show_bug.cgi?id=195303