Crackling noise from speakers

This has been happening for a while now and I cant find the problem.

Bassically after my pc has been on for more than 12 hours or so, the speakers start to crackle when playing sound. its not the speakers because headphones and my tv do the same. The problem stops once I restart the pc. 

 

Any ideas?

 

specs

Win 8

3750k

Intergraded graphics at the minute, graphics card is been fixed :( 

Gigabyte GA-Z77N-WIFI

Corsair 16GB vengence 1600Mhz

 

Have you installed the R2.70 Realtek Function driver for Realtek Azalia audio chip? 

had similar problem, then i installed newest drivers and fixed everything.