MLS Diffuser
A binary amplitude diffuser using pseudorandom sequences with only two well depths.
An MLS (Maximum Length Sequence) diffuser uses a binary pattern (wells at only two depths, typically full depth and zero) to scatter sound. Unlike QRD or PRD diffusers with continuously varying depths, MLS designs are simpler to construct while still achieving effective diffusion.
The sequence is generated using Linear Feedback Shift Registers (LFSRs), producing pseudorandom binary patterns with special correlation properties. Common sequence lengths are 7, 15, 31, or 63 elements (2^n - 1).
Advantages of MLS diffusers: • Simpler construction: only two well depths to cut • Good scattering across a wide bandwidth • Same mathematical rigor as other number-theoretic designs • Easier to manufacture with basic tools
The tradeoff is somewhat less uniform scattering compared to QRD designs, though this difference is often negligible in practical applications.
Practical Example
A 7-element MLS sequence
Binary pattern: 1, 1, 1, 0, 1, 0, 01s are full depth, 0s are flat surface. Only two depths makes CNC programming and hand construction much simpler.
Related Terms
QRD Diffuser · Diffusion · Scattering Coefficient
Glossar ·
Diffusor-Designer
ResonAia is an interactive acoustic design application. Enable JavaScript for the full experience, or follow the links above to explore the platform.