Tired of hearing your neighbors? Want to practice drums without complaints? Real soundproofing is harder than you think — but it's not impossible. Here's what actually works.
Calculate Your Wall's RatingSoundproofing is not the same as acoustic treatment.
Acoustic panels and foam reduce echo inside a room — they don't stop sound from going through walls. Real soundproofing requires mass, decoupling, and sealing. There are no cheap shortcuts.
If you want to block sound from neighbors or keep your music from bothering them, you need to understand STC (Sound Transmission Class) — the rating that measures how well a wall blocks sound.
STC (Sound Transmission Class) is a single number that rates how much sound a wall blocks. Higher = better isolation.
| STC | What You'll Hear | Typical Construction |
|---|---|---|
| 25-30 | Normal speech clearly understood | Single drywall, hollow door |
| 35-40 | Loud speech heard but not understood | Standard interior wall |
| 45-50 | Must strain to hear loud speech | Double drywall with insulation |
| 50-55 | Loud speech barely audible | Code minimum between apartments |
| 60+ | Most sounds inaudible | Double-stud wall, studio-grade |
The STC calculator shows your wall's current rating and helps you compare different construction options to find the best upgrade path.
Check Your Wall — FreeReal soundproofing combines these four elements. Skip any one and you'll get disappointing results.
Heavy materials block more sound. Double the mass = ~6 dB more isolation.
Break the vibration path. Sound can't travel through what isn't connected.
Insulation in cavities absorbs sound bouncing inside walls.
Gaps destroy isolation. A 1% opening can cut STC by 10+ points.
Foam reduces echo inside a room. It does almost nothing to stop sound going through walls. You need mass and decoupling, not absorption.
They don't. Not for echo, not for soundproofing, not for anything. Plus they're a fire hazard.
Blankets reduce echo slightly. They don't block sound transmission at all. Sound goes right through them and the wall behind.
Marketing nonsense. Paint is too thin to block sound. At best it might add 1-2 dB — imperceptible.
The weakest link in most rooms. A standard hollow-core door is STC 15-20. Solutions:
Single-pane windows are STC 25-28. Options:
Back-to-back outlets create a direct sound path. Solutions:
Ducts connecting rooms transmit sound. Solutions:
Footsteps and dropped objects are impact noise, rated by IIC (Impact Insulation Class), not STC. Blocking footsteps requires different treatment:
Use the IIC Calculator → to evaluate floor-ceiling assemblies.
The STC calculator lets you compare wall assemblies and see exactly how much improvement different construction methods provide.
Compare Wall OptionsLimited by lease and shared structure. You can:
Realistic improvement: 5-10 dB — noticeable but not transformative.
More options since you can modify structure:
Realistic improvement: 10-20 dB with moderate investment.
Purpose-built isolation with double-stud walls, floating floors, and isolated ceilings can hit STC 65+ and be nearly soundproof. Budget: $50-200+ per square foot for room-within-a-room construction.
First, seal every gap. Then add mass: a layer of 5/8" drywall with Green Glue, or resilient clips with double drywall. Expect 5-15 dB improvement depending on construction.
You can improve one wall, but sound also travels through the ceiling, floor, and other walls (flanking). The weakest path limits your results.
MLV adds mass in a thin layer. Useful in tight spaces or as part of a system. On its own, it adds 3-6 STC. Not magic, but a legitimate tool when mass is needed where drywall won't fit.
Heavy curtains help slightly with window transmission and can reduce echo. They won't soundproof a wall. Useful as part of an overall strategy, not a solution on their own.
DIY drywall + Green Glue: $2-4/sq ft. Resilient clips + double drywall: $5-10/sq ft professionally installed. Full room-within-a-room: $50-200+/sq ft.