Adveser Messages: 434 Registered: July 2009 Location: USA
Illuminati (1st Degree)
Carpet on the walls and ceiling.
I've hammered thick nails into the wall and used some pretty thick and heavy blankets. That gets the job done too. Not too perfect though. Different thicknesses and some overlap helps.
Cover up glass and metal before you even think about bothering with covering the drywall.