What acoustic panels actually do
Most “acoustic panels” are porous absorbers designed to reduce mid/high reflections and — when built thick enough — contribute to broadband control. They do not “soundproof” a room. Soundproofing is isolation (mass, decoupling, sealing).
Core materials
The core determines the absorption profile. Common cores include mineral wool, fiberglass, and acoustic foams. The key properties are flow resistivity, thickness, density, and how the material is mounted.
- Mineral wool / fiberglass: strong broadband performance when properly designed.
- Foam: typically effective in highs; performance varies by thickness and formulation.
- Hybrid builds: slats / membranes can extend low-frequency effectiveness.
Thickness & air gap
Thicker panels absorb lower frequencies. Adding an air gap behind a porous absorber shifts the effective range lower because the absorber sits closer to velocity maxima.
Fabric and breathability
Fabric must be acoustically transparent (breathable). If you can’t blow air through it, it can reflect highs and reduce performance. Decorative printing can work when done with correct textiles and processes.
Fire ratings and safety
Commercial applications often require fire-rated cores and fabrics (requirements vary by jurisdiction). Always match materials to the project’s compliance needs.
How to think about specs
If you see NRC, understand it’s a single-number summary (mostly mid bands). For serious design:
- Look for full-band absorption coefficients (125 Hz → 4 kHz).
- Ask about mounting method (direct mount vs air gap).
- Match the build to the problem (early reflections vs bass decay).