Acoustic Insulation Calculator (Mass Law)
Estimate the airborne sound reduction index of a single homogeneous partition from its surface mass and frequency using the mass law.
How to Use the Acoustic Insulation Calculator (Mass Law)
- Enter the surface mass of the partition in kg/m².
- Enter the frequency of interest in Hz.
- Click Calculate to see Rw at the chosen frequency plus 500 and 1000 Hz references.
حالات الاستخدام
- •Partition design for apartments and offices.
- •Estimating window and façade insulation targets.
- •Teaching building acoustics fundamentals.
الصيغة
Rw ≈ 20·log₁₀(m · f) − 48, where m is surface mass (kg/m²) and f is frequency (Hz).
الأسئلة الشائعة
Is mass law exact?
No. It is an idealised limit for limp, non-resonant single panels between the coincidence and resonance regions. Real partitions underperform near the coincidence dip and benefit from double-leaf constructions.
How much mass doubles the insulation?
The mass law gives a 6 dB increase per doubling of surface mass or frequency. In practice, 4–5 dB per doubling is a more realistic design rule.
Why subtract 48?
The constant comes from integrating the Berger mass law with a normal-incidence correction typical for architectural acoustics references.