Audio volume suddenly very low

Martin S. Weber Ephaeton at
Thu Jun 23 15:38:00 UTC 2016


I'm looking for pointers of things to try out. I have essentially done
nothing to the audio, I was experimenting with uhidd as I got a new
keyboard (I was using uhidd with the previous keyboard also) and faced
some problems with some key combos not sending keycodes. Suspecting a 
problem with uhidd, I stopped uhidd from starting,
removed its devd.conf, set it to NO in rc.conf, and removed the
cuse4bsd and vkbd modules from loader.conf.

Rebooted, and now my audio is extremely low. So low that even setting
hw.snd.vpc_0db to 1 (argh!) still requires my external amp to go to
+20 dB and it's still quiet. Before I was listening comfortably at
some -50 dB. That's _seven orders of magnitude_ fewer oomph.

Here's my audio hardware:

dmesg | grep pcm                                                                           
pcm0: <NVIDIA (0x0071) (HDMI/DP 8ch)> at nid 4 on hdaa0
pcm1: <NVIDIA (0x0071) (HDMI/DP 8ch)> at nid 5 on hdaa0
pcm2: <NVIDIA (0x0071) (HDMI/DP 8ch)> at nid 6 on hdaa0
pcm3: <NVIDIA (0x0071) (HDMI/DP 8ch)> at nid 7 on hdaa0
pcm4: <Realtek (0x0900) (Rear Analog 5.1/2.0)> at nid 20,22,21 and 24,26 on hdaa1
pcm5: <Realtek (0x0900) (Front Analog)> at nid 27 and 25 on hdaa1
pcm6: <Realtek (0x0900) (Onboard Digital)> at nid 17 on hdaa1
pcm7: <Realtek (0x0900) (Rear Digital)> at nid 30 on hdaa1
pcm8: <USB audio> on uaudio0

I'm usually using pcm4 (default unit =4, see below).

I use musicpd (ugh, only for cantata) to play music. Its configuration
essentially boils down to "audio_output { type "oss" } ".

I haven't touched my mpd.conf between those boots though.

My sysctl settings for hw.snd (the ones I explicitly put in /etc/sysctl.conf) are 


The settings for hw.snd in general are:
$ sysctl hw.snd                                                   
hw.snd.maxautovchans: 16
hw.snd.default_unit: 4
hw.snd.version: 2009061500/amd64
hw.snd.default_auto: 1
hw.snd.verbose: 0
hw.snd.vpc_mixer_bypass: 1
hw.snd.feeder_rate_quality: 1
hw.snd.feeder_rate_round: 25
hw.snd.feeder_rate_max: 2016000
hw.snd.feeder_rate_min: 1
hw.snd.feeder_rate_polyphase_max: 183040
hw.snd.feeder_rate_presets: 100:8:0.85 100:36:0.92 100:164:0.97
hw.snd.feeder_eq_exact_rate: 0
hw.snd.feeder_eq_presets: PEQ:16000,0.2500,62,0.2500:-9,9,1.0:44100,48000,88200,96000,176400,192000
hw.snd.basename_clone: 1
hw.snd.compat_linux_mmap: 0
hw.snd.vpc_reset: 0
hw.snd.vpc_0db: 70
hw.snd.vpc_autoreset: 0
hw.snd.latency_profile: 1
hw.snd.latency: 5
hw.snd.report_soft_matrix: 1
hw.snd.report_soft_formats: 1

Again, those 0db = 70 used to be enough to drive the card (even though with
considerably more noise and considerably less output than under win or lin),
but now it's ultra-quiet. I haven't updated my system between boots, it's
still a 10.3-RELEASE-p5.

I haven't changed hardware either.

I have experienced problems with booting FreeBSD "warmly" wrt sound (i.e.,
boot e.g. win and then restart the box for a warm reboot, sound output
would be "garbled" with many artifacts and playback errors), so I'm cold-booting
the box, but nothing has changed in this procedure either. This used to work.

So.. any ideas how I get my sound back?


More information about the freebsd-questions mailing list