1" x 12" x 12" Charcoal Acoustic Studio Wedge Foam 12 Pack by Deluxe Foam Pack of 12. Covers 12 sq. ft. For basic soundproofing. Provides moderate sound control on walls or ceilings. Overall NRC: 0.40 Best for when absolute sound deadening is not required, but moderate deadening is desired. 1 inch wedge foam is most effective on mid-to-high frequency ranges.