What Is the Cheapest Way to DIY Soundproofing?
Updated
The cheapest DIY soundproofing is sealing air leaks with acoustical caulk, outlet putty pads and door weatherstrip, and all you need to put them in is a caulk gun and a utility knife. Do it first, because one unsealed 1/8 in. gap 1 ft long drops a wall from STC 46 to 36 in PABCO's Sound Design Guide (opens in a new tab).
- Wall base: pull the baseboard and caulk the gap between the drywall and the floor with a non-hardening acoustical sealant.
- Outlets: wrap every box in a putty pad.
- Door: weatherstrip the stops and put a sweep on the bottom.
Watch out: homemade soundproofing for echo is a whole different job. Bare 2 in. Owens Corning 703 fiberglass board absorbs well, at NRC 1.00 on its data sheet (opens in a new tab), but a light absorber like that won't keep the neighbor's noise out. The soundproof panels guide explains why blocking and absorbing take different materials.
Once the leaks are sealed, the next DIY steps for a noisy wall are filling an empty cavity and screwing on a second layer of drywall, in the order laid out in the cheapest way to soundproof a wall. There are answers to other low-cost questions in the soundproof panels FAQ.