You need space of at least 4-6inches between head boxes
A. so you can give em a nudge without fear of damage
B. I hate playing handsies, it just doesn't feel right! know what I mean when you have that
uncomfortable, brief touch.
C. so you can squeeze in between if you need to get to back box
D. It just looks better and well thought out
E. Breathing room for heat issues( well maybe)
F. Show off cabinet art.