On Mon, Jul 18, 2022 at 02:42:07PM +0800, zhaochengyi@xxxxxxxxxxxxx wrote: > On 2022/7/17 上午3:18, Sean Greenslade wrote: > > On Fri, Jul 15, 2022 at 06:04:49PM +0800, zhaochengyi@xxxxxxxxxxxxx wrote: > > > Hi guys, > > > > > > On a special PC, it is required to start the pulseaudio daemon > > > with some special parameters in the file /etc/pulse/daemon.conf, > > > as follows: > > > > > > ------- > > > default-sample-rate = 48000 > > > default-fragments = 2 > > > default-fragment-size-msec = 20 > > > ------- > > > > > > When plugging in a USB headset with a separate sound card to this special > > > PC, > > > I found that there was a noise in the playback audio. After investigation, > > > the sound card of the USB headset needs to use the following default > > > parameters. > > > > > > ------- > > > default-sample-rate = 44100 > > > default-fragments = 4 > > > default-fragment-size-msec = 25 > > > ------- > > After my further investigation, I found that noise is only generated > when changing the sink-input volume (pa_context_set_sink_input_volume), > but not when changing the sink volume (pa_context_set_sink_volume_by_index). Can you describe this noise more specifically? Does it go away with larger fragment size / counts? Have you enabled or disabled tsched? Have you run with Pulse debug logging enabled and looked for any hints there (e.g. underruns)? --Sean
