Audio Lag Appearing In Games

Certain games are affected by this lag. The game will run smooth for a while (regardless of graphic settings) but eventually the audio will start crackling. Then graphical lag will begin. Changing the graphics from high to low does nothing and the lag persists for a while after the game is closed. Thing is, setting the affinity of the game to one core prevents the lag from turning up in the first place, however, when set to 1 core I need to have the graphics set to minimum or suffer graphical lag (which stops when settings are set down).When this first appeared I noticed that audiodg was using about 30% of my cpu. Took advice and changed my sound settings which got it down to 5% at worst. Now my CPU stays at about 70% during the lag and memory is in the 80% range. So I dont get what the problem is, if my cpu and memory havent hit max it shouldnt lag.