Hi, I'm brand new to this forum, but I've always found good information on other people's threads. Anyway, I have a Line 6 head on top of a Crate cab. I'm not sure of the exact model numbers seeing as they live at my singer's house. Anyway, I play pretty heavy music at anywhere from quarter to half volume with the channel volume at half and I use an Ibanez guitar with active pickups.

Now the problem:

Sometimes while I'm playing, we all hear a slight crackle in the guitar tone. I'm using a speaker cable not an instrument cable to connect the head and cabinet and a 12 foot instrument cable to connect the guitar to the head.

What is causing the crackle and what steps should I take to correct it? Thanks for any info you might be able to provide!