Sound Problems. Please Help!

Hi all!

Ill start by saying that I installed Ubuntu for the first time today, so I'm no expert. Everything is working fine (so far as I can tell), except audio. Basically its not working :( All I get is about 0.5sec 'crackle' at login and can get similar 'crackle' when testing sound in the Sound Settings. And even that is audible only when the system volume and headphones are turned very high. I have tried both standard Ubuntu 14.04 and GNOME (Ubuntu 14.10). Clean installed system 3 times still the same issue. Anyone have any experience with this? Any idea how to fix it?

Are you using PulseAudio or ALSA?

Check with:

sudo apt list --installed | grep pulseaudio

Also what soundcard(s) are you using

cat /proc/asound/cards

ALSA(?) or at least I was able to run it form terminal with:

alsamixer.

Anyhow, this is what I got with that command:

WARNING: apt does not have a stable CLI interface yet. Use with caution in scripts.

gstreamer0.10-pulseaudio/trusty,now 0.10.31-3+nmu1ubuntu5 amd64 [installed,automatic]
gstreamer1.0-pulseaudio/trusty-updates,now 1.2.4-1~ubuntu1 amd64 [installed,automatic]
pulseaudio/trusty-updates,now 1:4.0-0ubuntu11.1 amd64 [installed,automatic]
pulseaudio-module-bluetooth/trusty-updates,now 1:4.0-0ubuntu11.1 amd64 [installed]
pulseaudio-module-x11/trusty-updates,now 1:4.0-0ubuntu11.1 amd64 [installed,automatic]
pulseaudio-utils/trusty-updates,now 1:4.0-0ubuntu11.1 amd64 [installed,automatic]

Cards:

0 [HDMI ]: HDA-Intel - HDA Intel HDMI
HDA Intel HDMI at 0xf7c34000 irq 48
1 [PCH ]: HDA-Intel - HDA Intel PCH
HDA Intel PCH at 0xf7c30000 irq 46

Also, tried LiveUSB and had the same problem.

Ok, you're using PulseAudio.
Please have a look at the PulseAudio log files (somewhere in /var/log/)
If you find anything suspicious, please post it here.

Also, check out this Section of the ArchWiki:
https://wiki.archlinux.org/index.php/PulseAudio/Troubleshooting#Glitches.2C_skips_or_crackling

I had the same exact problem in windows, when I was using my old EVGA GTX660, I RMA'd it thinking the issue was with the GPU, EVGA sent me a new one, but told me that the original was in perfect working order, and their technicians said it was most likely a bad power supply.

I'm still not sure what the issue was, but it hasn't happened again since switching to a 970 and switching to motherboard audio.

Edit: The issue was also accompanied by video playback issues, and the GPU was hooked up via HDMI

Just tried to connect headphones to front panel connection and lo and behold - sound works like charm. So it seems only the rear audio output doesn't work like its supposed to. Rear Mic-in works.

I would suggest opening up the pulseaudio and the alsa settings to make sure that the channels are not muted.

Defaults in pulseaudio and alsa is to have the channels set to mute, usually Ubuntu unmutes the channels though for you. If you have HDMI that supports audio it may have unmuted this as the main channel, then you have to go in and set your soundcard/motherboards audio ports as the main channels.

Well... the problem has just gone away. Turned the PC on this morning and audio is fine. No idea why :P

@venomfang I did check and ALSA Mixer was showing that every channel was on and turned up. PulseAudio Volume Control also said that everything was working and now it is.
It seems that pluging the headstet in the front panel connector and re-pluging it in the back, plus full shutdown has solved the problem.

Anyway... thanks everyone! Hopefuly nothing else crops up :)