Thanks, after reading your thoughts it reminds me that, whats counts is how it sounds with the other elements. So the bus is where I was leaning to as well. I'd been watching the EQ compression course and for the examples its single tracks for bass etc but all the elements are High passed before starting work on "a sound" so I guess the bus becomes the element were the HP would help sit the bass better with Kick etc. (unless there's anything that simply needs removing before starting)
Thanks again you've help me think that through better.