I searched google and this crackle audio bug seems to be a very well known issue worldwide. Here is one good example.
http://forums.forzamotorsport.net/turn10_postst1893_sound-issues.aspx
I know for a fact it is not my surround sound because I turned that off and turned the tv audio up and had the same problem. Plus the 2 people in my room do not have surround sound and they had the issue. It is 100% the game for sure. Just need to figure out a work around. Hopefully when I turn the X1 back on tonight, the problem will be resolved.
Seems to be resolved by turning ON the "Power save mode". I did that last night before I went to bed so hopefully that resolves the issue.
The ONLY difference last night is that I hooked the Kinect up. I wonder if that is part of the issue? Maybe if I disconnect that the problem will go away. Hmm. That will be an interesting experiment. Because technically I never had this issue until I hooked up the Kinect. BUt that is only a guess. All trial and error. No I don't think that's the issue because I had similar problem once in a while in F4 and I never had the Kinect on the 360. So that's probably not it.