KDE Sound
 

I am not sure what the permissions on sound devices should be but I logged in under Slackware 13.0 the first few times fine, then all of a sudden sound stopped working under KDE. I could still hear sounds by executing aplay as root, so I did a chmod 666 on the following devices:
adsp
audio
dsp
mixer
sequencer
sequencer2

Bad move? Sound is working again as a result. But not sure if this was the best way to solve the problem. The only thing that changed I believe was that I switched from run level 3 to 4.

The default is 660. You should add yourself as a member of the audio group.

KDE Sound
 

There is something funky with the X11 with KDM/GDM/XDM (session managers) mode in 13.0. I returned to level 3 and sound works perfect by default.

I've noticed some sound oddities as well. I can have sound in flash one moment and then later, in the same session no sound in flash, yet I still have sound in Amarok. I restarted the computer and everything worked again. Did I miss a setup/configure in KDE?

KDE sound
 

I had to configure kmix to support my microphone. No other configuration was necessary. I have had some weird delay in Amarok. But flash streaming has worked fine.