|Originally posted by Terry Montlick
Not a dumb question at all. The general problem with letting subs vibrate structural parts is that the sound radiation then becomes uncontrolled. You get re-radiation from these parts that can now interact with the direct airborne sound from the sub in unforeseeable ways, and create distortion. Such re-radiation will happen in amounts and at frequencies which are determined by the unknown vibrational characteristics of the structural parts. This defeats the purpose of having a quality, properly designed subwoofer.
Of course, if all you want to do is make a lot of noise, all bets are off.
How about putting a compact subwoofer in a column?
Attached is a concept drawing.
I was thinking of building the base of the column out of a three-sided MDF box attached to the wall. The top of the box would have a shelf that the subwoofer would sit on at about 4 feet off the floor. A frame would extend from the shelf to the ceiling soffit. It would be wrapped in acoustically transparent fabric and would conceal both the subwoofer and a side surround speaker. The base would be stuffed with fibreglass insulation.
Since the subwoofer is front-firing, sits on top of the structure rather than inside, and is designed for in-cabinet applications, I was hoping that unwanted vibrations might be kept to an acceptable level, especially if I used rubber feet. What do you think?