Instructions, Manuals and Specifications NRC Certificate: Riverbank Acoustical Laboratories Test Report Posted on November 19, 2012November 3, 2017 by VB2Go 19 Nov NRC Certificate for VocalBoothToGo More information NRC can be found in Articles on NRC Noise Reduction Coefficients Â Â Â Â Â Q) I am interested in your soundproof curtain. Our doorway is 65″ tall and 80″ tall . Can I use your curtain to soundproof adjoining two rooms instead of installing a double door? Q) Which type of booth do I need? A Vocal Booth or a Sound Booth?