There is a product called dynamat that I used when I was into car audio, 25 years ago, that would fit your needs. Dynamat is an excellent product and easy to work with. Good Luck.
3M Sound Damping Foil Tape
I just learned about this product and am wondering if anyone here has tried it and can comment on its merits or lack thereof.
http://www.zorotools.com/g/00090261/k-G4287464?srccode=cii_18492716&cpncode=30-48999843-2&utm_source=channel_intelligence&utm_medium=referral&utm_campaign=bingshopping
I'm thinking to adhere it to the bottom of my rack's MDF shelves and possibly to the inside of the housing to my CD player and phono preamp.
http://www.zorotools.com/g/00090261/k-G4287464?srccode=cii_18492716&cpncode=30-48999843-2&utm_source=channel_intelligence&utm_medium=referral&utm_campaign=bingshopping
I'm thinking to adhere it to the bottom of my rack's MDF shelves and possibly to the inside of the housing to my CD player and phono preamp.