mineral fiber insulation density
USG Research conducted the tests with a. variety of partition designs. The results: Thermaï¬ ber mineral wool. insulation in the 2.5 to 3.0 lbs/cu.ft. density range proved the best. overall acoustical performance. Densities above the 3 lbs/cu.ft. provided improved sound attenuation at high frequencies, but the. low-frequency performance starts to suffer at higher densities.