My background is live sound. The fact that they make combo amps with the amp inside the speaker cab and assuming these principles apply to all amps in general really baffles me. They would design and sell these combos for thousands without properly dampening the amps. We often place our amps on top of our cabs. I play bass guitar and to think I have been potentiay killing my tone does not make me happy.
Maybe with live sound it's not as important but after researching these principles and the lengths audiophiles go through to dampen with the results that are gained really opened my eyes to this issue!