Analysis of the effect of changes in sequence position on the performance of quadratic residue diffuser (QRD) skyline.

Quadratic Residue Diffuser Skyline (SQRD) is an acoustic panel with the principle of working as a diffuser with a specific geometry (uneven), rigid and scatter sounds. SQRD is arranged with a multidimensional QRD pattern. The study aims to analyze the effect of shifting SQRD sequence positions on panels performance with SPL directivity parameters and diffusion coefficients. The SQRD used in this study has a size of N = 11. The shift variations used are symmetry configuration (V0), shift one (V1), to shift five (V5). The scattering frequency used for the analysis is 1600Hz, 2000Hz, 2500Hz, 3150Hz. The results showed that the shift in the position of SQRD sequences did not provide significant changes. This is shown by the pattern of SPL directivity that are almost uniform for all variations, and each variation of the panels used has good diffuser characteristics with a diffusion coefficient value above 0.83. [ABSTRACT FROM AUTHOR]