Re: "Crack" noise on either forward or backcast
I have noticed this when I apply an inordinate amount of speed to the forward cast compared with the back cast. This throws the timing off and the line does not get straightened out before forward cast begins. This makes the line that is still in the back cast straighten out and begin it's forward cast too quickly thus making it very similar to a whip. You will find this is a great way to get rid of a few flies too.
All Means All