What Is the Sound Transmission Loss & Mass Law Partition Calculator?
Sound Transmission Loss (TL) is the number of decibels by which airborne sound power is attenuated when passing through a solid partition.
How Does the Sound Transmission Loss & Mass Law Partition Calculator Work?
Under random-incidence acoustic mass law, TL = 20·log10(m·f) - 47.5 + bonus. Acoustic energy transmission is τ = 10^(-TL/10).
Sound Transmission Loss & Mass Law Partition Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Acoustic mass law states that partition sound transmission loss increases by 6 dB for every doubling of surface density m (kg/m²) or frequency f (Hz).
How to Use the Sound Transmission Loss & Mass Law Partition Calculator
- Enter wall or slab surface density in kg/m².
- Specify acoustic frequency in Hz.
- Add cavity insulation or decoupling bonus dB.
Step-by-Step Example Calculation
Standard Drywall Partition at 500 Hz
Input Values:
Understanding Your Result
Transmission Loss (TL): Decibels of sound blocked by the partition.
Transmission Ratio (τ): Fraction of acoustic sound energy penetrating the wall.
Privacy Level: Categorization from poor privacy up to confidential conference room rating.
Factors That Affect the Result
- Surface density is the primary driver; airtight sealing is critical because tiny flanking air cracks bypass high-mass walls.
When Should You Use This Calculator?
- Designing party walls for apartments, recording studios, cinema isolation, and executive conference rooms.
Assumptions & Limitations
- Assumes mass-controlled regime; does not model coincidence dip or low-frequency structural panel resonance.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Random-incidence diffuse acoustic field formulation.