Some problems have the same cause for me, it is a quite common sound-issue, known as the "alsa-pulse-issue". Symptoms are crackling and so on ruining the sound and more or less an effect on performance. Sometimes a crash.
The logs repeated this line (according to how long you were in the game for thousands of lines):
the solution for my issue demands changes on the file "default.pa". how to locate and to open it with "sudo" i could read in link 3. i had to look, what i really needed there and to modifiy a little bit (i wrote "gedit" instead of "kate"). (btw - link 5 offers a different solution on this file, just compared)
i followed link 6 so far, but there is a second file, which must be edited, ".asoundrc". first I couldn't find it (even looking for hidden files; well, i see it is one) on my computer. later i saw link 7, who explains, that alsa is running without this file in default and it isn't needed always. but its purpose is to define, what is not default, and i wanted to do that. so i put the "changes" from link 6 to a textfile and saved it to my home as ".soundrc".
In the end i tried the soundtest, mentioned in link 6. but i think, something went wrong (or simply: it doesn't work so far). i heard a crackling sound only and don't got the message, which should pop up.
Instead in terminal appeared:
fixme:winediag:AUDDRV_GetAudioEndpoint Winepulse is not officially supported by the wine project
fixme:winediag:AUDDRV_GetAudioEndpoint For sound related feedback and support, please visit http://ubuntuforums.org/showthread.php?t=1960599
err:ole:CoInitializeEx Attempt to change threading model of this apartment from multi-threaded to apartment threaded
while testing i got a wine-configuration window. it says chosen driver is "winepulse.drv". all standards are set to "system standard", but scrolling down them just reveals "Pulseaudio" (seems to be a version 4.0).
So i am still with pulseaudio and not with alsa directly ?
Hm, next to "default.pa" is a "system.pa" - i shouldn't fiddle around with that, should i?
Perhaps i forgot to modify something ?
I am an old veteran gamer from times of C=64 on - used to ms-dos and basic - but i prefer linux ubuntu trusty tahr and dislike windy win-doh!-s and nasty nsa and webwielding whackers and spying spiders - face me in a dungeon and i'll show you (you mobs)!