Mineral wool acoustic panel
GRAMMA/Great GRAMMA Auralex Acoustics

The best way to tighten up a room's sound and make it more soundproof in the process is to design it right, build it tight and make the partitions as dense as possible. That's where our specialized Mineral Fiber sound insulation comes in. It's WAY more dense than "the pink stuff" and is specifically designed for acoustical usage. It yields much better bass trapping, overall absorption, thermal characteristics, moisture absorption and sound transmission loss (isolation) than any other product we've found.

Advantages vs. Std. Fiberglass: better sound isolation, better acoustic absorption, lower moisture absorption, better flame spread and smoke density, 1200° burn point vs. 650°