Do Soundproof Panels Work in Apartments?
Updated
Soundproof panels work in apartments for echo, not for neighbor noise. A 2 in. fiberglass panel soaks up nearly all the mid-range sound that hits it (NRC 1.00 for Owens Corning 703 (opens in a new tab)), but it weighs only about 0.5 lb/sq ft (3.0 lb/cu ft x 2 / 12), and blocking sound takes weight.
For scale, a full layer of 5/8 in. drywall weighs more than four times as much, and it only took an insulated wall from STC 34 to 37 in USG's lab tests (opens in a new tab). A panel adds less than that.
Watch out: if you can make out words through a wall built to the STC 50 code, sound is probably sneaking around it, under the entry door or through the outlets. One unsealed 1/8 in. gap 1 ft long drops a wall from STC 46 to 36 in PABCO's guide (opens in a new tab).
So as a renter, you'll get more out of a door sweep, gaskets and outlet putty pads (all of which come off at move-out) than out of panels. The step-by-step method is in how to block noise from a shared wall, deposit-safe products are in soundproof panels for apartments, and the soundproof panels guide covers which panel to buy for echo. There are more answers in the soundproof panels FAQ.