Hey Doc, some people actually listen to music at "volume". Not everyone plays "genteel" music at "mouse level". As such, air-born energy is transmitted into everything within the room.
As to Ndmaitre's question, i would loose the marble and build an all wood rack. Take a gander at some of the other "rack" based threads in the archive. I know that Ken aka Caterham 1700 just posted some info about recommended woods for shelving. I would take those suggestions into serious consideration.
Either way, listen to what your head and heart tell you, as only that will make you happy. You might have to change things along the way, but there is a LOT to be said for first hand experience and learning the "hard way". Sean
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