I am in the planning stages for a ' built ' in audio cabinet 29w x 24d x 73h . As you can see it will be quite tall . It is designed tuck under a low point in the finished ceiling caused by a heating duct . My question is on the feasibility of using the bottom of the cabinet to house my sub 20"h with the audio components above . Should I be concerned with the vibration . Is there a damping material that would improve the result if placed under the sub or is it just a bad idea ?