Running my combo/cab with 2-12 and horn on top of my 115, I find that I needed a thick towel to take a bad noise out of them. Are they coupling to each other and the towel just muted that or is there another dynamic here of which I am not aware? The top cab has it's original and very supple thick rubber cookie-feet, and I take the casters off when I stack it on top of the 115. The 115 is on casters and it's not apparently the problem - I think. That towel trick worked - is there a better way to isolate them from each other in a stack formation: a special pad or insulator? The towel looks kind frumpy. Maybe I can get the cat-lady across the road to make me some really thick doilies.