Soundproofing insulation that actually quiets the room.

Code minimum for shared walls is STC 50. STC 55 starts to feel quiet between rooms; STC 60 is what you want for a recording space. We design to a target STC, not just to a product. Mineral wool gets you maybe 4 to 6 points; the rest is mass, decoupling, and sealing.

It helps but it isn't the whole answer. Most noise comes through gaps, doors, and flanking paths. Plan on sealing penetrations, gasketing the door, and possibly adding a second layer of drywall with green glue. We design the whole assembly.

We can dense-pack cellulose into a closed wall for some sound improvement, but the bigger gains come from re-rocking with a damping compound layer. We will tell you what level of work matches your goal.