Latency issues with low powered machines and pulse
Some people have found Pulseaudio to be a little too hungry for their particular system. Although Pulse is fine for most scenarios it may be necessary to turn off some of the more high end features it enables by default.
Disable Glitch Free
Glitch-free support in some cases may expose problems in the alsadrivers below. If there is an unacceptable latency when trying to do something relatively harmless (like play an MP3 with Rhythmbox) then please try this.
!!Warning this does break upgrades and will be relevant for all user sessions as the edits are applied to /etc/pulse/default.pa!!
Open /etc/pulse/default.pa, and look for this line
Add tsched=0 to the end of the line, like so:
load-module module-udev-detect tsched=0
If you notice no difference then please revert back to what it was before and reboot. Glitch Free is a nice feature to have if it works fine on your machine. More reading here