[fedora-virt] improving win7 guest sound and video performance

Hi, I wonder if someone can help. Video performance (youtube) in my win7 guest is decent but the sound somehow is slow, and I mean slow like playing a record at low rpm (no chopped sound or jitter). I'm running an up to date fedora 20 host. My guest definition can be found here: http://pastebin.com/YybiPnAp Any ideas about what settings can be tweaked to get the best possible video and sound performance out of a win7 guest? Thanks in advance, Daniel