I have a headless machine connected to my sound system, and I am using it to run a music playing daemon that I control over the network. (Among other things)

However, I can't seem to be able to have sound come out of my speakers without running X.

I am running pulse audio in a system wide instance and my daemon is not running within X. Nevertheless, when my daemon is playing music without me hearing it, I can fix it by running startx in an unrelated session. After X starts, I can hear the sound. The sound disappears again if I kill the X server.

Interestingly/annoyingly, the sound also stops after X has been running for a few minutes. This could possibly be because of a screen saver of some sort, but I haven't been able to verify or falsify this theory.

So my current workaround is to ssh into the box whenever I want music and startx, and restart it every fifteen minutes or so. I'd like to do better.

I have been able to verify the following:

• Adjustments in alsamixer have no effect on this problem. The relevant output channel is never muted
• In alsamixer, I can see no difference between when the sound is working and when it isn't
• Nothing is muted in pactl list
• There is no difference in the output from pactl list between before starting X and after it's started. (Except the identifier of the pactl instance connected to pulse, which is different each time you run pactl)
• The user running the music daemon is a member of the groups audio, pulse and pulse-access
• The music daemon program does not report any error messages and acts as if it is playing the music like it should
• Some form of dbus daemon is running. ps aux|grep dbus reports dbus-daemon --system --fork --activation=upstart before and after I have started X

Some details about my hardware:

• Motherboard: http://www.asus.com/Motherboards/AT5IONTI_DELUXE/
• Sound chip: Nvidia GPU 0b HDMI/DP (from alsamixer)
• Using HDMI for output
• (Machine also has an Intel Realtek ALC887 that I am not using)

Output of lsmod:

Module                  Size  Used by
deflate                12617  0 
zlib_deflate           27139  1 deflate
ctr                    13201  0 
twofish_generic        16635  0 
twofish_x86_64_3way    25287  0 
twofish_x86_64         12907  1 twofish_x86_64_3way
twofish_common         20919  3 twofish_generic,twofish_x86_64_3way,twofish_x86_64
camellia               29348  0 
serpent                29125  0 
blowfish_generic       12530  0 
blowfish_x86_64        21466  0 
blowfish_common        16739  2 blowfish_generic,blowfish_x86_64
cast5                  25112  0 
des_generic            21415  0 
xcbc                   12815  0 
rmd160                 16744  0 
bnep                   18281  2 
rfcomm                 47604  12 
sha512_generic         12796  0 
crypto_null            12918  0 
parport_pc             32866  0 
af_key                 36389  0 
ppdev                  17113  0 
binfmt_misc            17540  1 
nfsd                  281980  2 
ext2                   73795  1 
nfs                   436929  1 
lockd                  90326  2 nfsd,nfs
fscache                61529  1 nfs
auth_rpcgss            53380  2 nfsd,nfs
nfs_acl                12883  2 nfsd,nfs
sunrpc                255224  16 nfsd,nfs,lockd,auth_rpcgss,nfs_acl
btusb                  18332  2 
vesafb                 13844  2 
pl2303                 17957  1 
ath3k                  12961  0 
bluetooth             180153  24 bnep,rfcomm,btusb,ath3k
snd_hda_codec_hdmi     32474  4 
nvidia              11308613  0 
ftdi_sio               40679  1 
usbserial              47113  6 pl2303,ftdi_sio
psmouse                97485  0 
snd_hda_codec_realtek   224173  1 
snd_hda_intel          33719  5 
snd_hda_codec         127706  3 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel
serio_raw              13211  0 
snd_seq_midi           13324  0 
snd_hwdep              17764  1 snd_hda_codec
snd_pcm                97275  3 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec
snd_rawmidi            30748  1 snd_seq_midi
snd_seq_midi_event     14899  1 snd_seq_midi
snd_seq                61929  2 snd_seq_midi,snd_seq_midi_event
snd_timer              29990  2 snd_pcm,snd_seq
snd_seq_device         14540  3 snd_seq_midi,snd_rawmidi,snd_seq
snd                    79041  20 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
asus_atk0110           18078  0 
mac_hid                13253  0 
jc42                   13948  0 
soundcore              15091  1 snd
snd_page_alloc         18529  2 snd_hda_intel,snd_pcm
coretemp               13554  0 
i2c_i801               17570  0 
lp                     17799  0 
parport                46562  3 parport_pc,ppdev,lp
r8169                  62154  0 

Any ideas? What does X do that's so important?