HX Audio Lab

Sound Splash -- Acoustical Diffuser Design Software

Newest release of Sound Splash: v1.2 (June 2011)

Sound Splash is a calculator to design custom diffusers. This software is not available for public. For those who are interested in obtaining a copy of this software, please contact for price quote. Sound Splash is a proprietary software of HX Audio Lab. A LT version of Sound Splash is available for public. The LT version is limited on calculating PRD and QRD with low N value. Download link can be found at the bottom of this page.

The invention of the phase grating diffuser by M. Schroeder is one of the most important events in the design of diffusers. Starting from Quadratic Residue Diffuser (QRD), there have been many new developments, improvements and variations, such as Primitive Root Diffuser (PRD), Type-II Luke Sequence Diffuser (LSD), Power Residue Diffuser (PWRD), etc. Sound Splash is also able to calculate Huffman sequence diffuser (non-integer based).

Sound Splash brings together several most popular Schroeder diffuser concepts, Huffman sequence diffuser and provides the users a convenient interface to design diffusers. Sound Splash is capable of making combinations of one dimensional QRD, PRD, LSD, PWRD, Huffman sequence (non-integer based sequence) and two dimensional QRD, PRD, LSD, Huffman. A sub-program for designing a two dimensional maximum length sequence (MLS) diffuser is also included.

Sound Splash provides a quick way to calculate and design several diffusers as listed below:
Quadratic Residue Diffuser (1D and 2D)
Primitive Root Diffuser (1D and 2D)
Type-II Luke Sequence Diffuser (1D and 2D)
Power Residue Diffuser (1D)
Maximum Length Sequence Diffuser (2D)
Huffman Sequence Diffuser (1D and 2D)

The two-dimensional diffusers are calculated using array extrapolation (simple) and Chinese Remainder Theorem. This will give user more flexibility to design different type of diffusers.

A simple polar response is also included in the software. The polar response prediction is not intended as an accurate prediction (boundary element method calculation is not implemented). This feature allows user to roughly predict the sound dispersion, flat plate frequency problem, relatively comparing the polar of different design(s) and so on.

The polar response is simply calculated by taking several points in the front of diffuser and considering each well opening as a point source (see the picture below).

A simple algorithm to calculate sine wave interference is performed at each point in the front of the diffuser. Several screenshots are shown below:

Comparing a 1D QRD and 1D PRD using same design frequency (500Hz), two periods and N (13) at 2500Hz.
Comparing flat plate frequency problem in 1D LSD and 1D QRD, same design as above at 3500Hz.
Comparing a period of 2D PRD with Chinese Remainder Theorem (6x7 rows) and simple extrapolation (6x6 rows) at 5000Hz with same design frequency (500Hz).
Flexibility in polar view. Overlaid polar and showing flat plate frequency on 2D diffuser design.

Sound Splash is a complex diffuser builder/calculator. Several special features are included in the software for advanced use.

• QRD optimizer

Allows user to design a QRD based on a specific depth and calculate a good integer constant value for good low frequency diffusion.

• Integer constant option.

Allows user to introduce constant phase shift to the QRD.

• Automatic primitive root finder.

Allows user to select a primitive root value.

• Out of phase and reverse option.
• Family number option for LSD and PWRD.
• Two PRD equations.
• N up to 2000 with automatic prime value finder.

References are taken from various Journals of Acoustical Society of America, Audio Engineering Society and acoustical books such as Acoustic Absorbers and Diffusers (Cox & D'Antonio), Acoustics (Beranek), Master Handbook of Acoustics (Everest), etc.

Download Sound Splash 1.2 LT
Note: Please run setup.exe to proceed with the installation.