Acoustic Dampening Wool Serge is double-sided raised fabric with optimum acoustic qualities. This inherently flame retardant (IFR) wool is the best value for money. Wool Serge is one of the most renowned fabrics for theatrical drapes, borders, legs, as well as skirting. Used to make Acoustic curtains, the wool serge is ideal weave for dampening sound and adjusting the acoustic properties of a venue.