Abstract: A two-dimensional primitive root diffusor includes a two-dimensional pattern of wells, the depths of which are determined through operation of primitive root sequence theory. A prime number N is chosen such that N-1 has two coprime factors which are non-divisible into each other. From the prime number, a primitive root is determined and, in the preferred embodiment, an algorithm is used to determine sequence values for each well. Each sequence value is proportional to the well depth, with each sequence value being multiplied by the design wavelength and then divided by 2N to arrive at the actual well depth value.

Abstract: Disclosed are a variety of structural acoustical cinder blocks including locking blocks which are intended to be assembled together through the use of mortar to provide a diffusor of desired shape and configuration. Each diffusor includes a plurality of wells, the depths of which are determined through the use of number theory sequences, such as, for example, the quadratic-residue sequence developed by Karl Frederick Gauss. The surface irregularities formed in the blocks are unique in that they provide a flat power spectrum and constant scattered energy in the diffraction directions. Each of the blocks including wells also includes a low frequency sound absorbing chamber. The blocks are installed such that there is a stacked bond on the diffusing face and a running bond on the structural rear face. If desired, a single block may be made which includes an entire sequence of wells and dividers.

Abstract: Disclosed are embodiments of structural acoustical cinder blocks including blocks which are intended to be assembled together through the use of mortar to provide a diffusor of desired shape and configuration. Each diffusor includes a plurality of wells, the depths of which are determined through the use of number theory sequences, such as, for example, the quadratic-residue sequence developed by Karl Frederick Gauss. The surface irregularities formed in the blocks are unique in that they provide a flat power spectrum and constant scattered energy in the diffraction directions. Each of the blocks also includes a low frequency sound absorbing chamber. As the blocks are installed, a structural stacked bond is formed on both the diffusor face and the rear structural face. If desired, a single block may be made which includes an entire sequence of wells and dividers.

Abstract: The present invention relates to an acoustical diffusor device which is made up of a plurality of specially designed and shaped cinder or concrete blocks which may be assembled together through the use of mortar to provide a diffusor of desired shape and configuration. Each diffusor includes a plurality of wells, the depths of which are determined through the use of number theory sequences, such as the quadratic-residue sequence developed by Karl Frederick Gauss. These surface irregularities are unique in that they provide a flat power spectrum and constant scattered energy in the diffraction directions.

Abstract: The present invention relates to an acoustical diffusor device which is made up of a plurality of specially designed and shaped cinder or concrete blocks which may be assembled together through the use of mortar to provide a diffusor of desired shape and configuration. Each diffusor includes a plurality of wells, the depths of which are determined through the use of number theory sequences, such as the quadratic-residue sequence developed by Karl Frederick Gauss. These surface irregularities arenique in that they provide a flat power spectrum and constant scattered energy in the diffraction directions.

Abstract: Disclosed herein is an improved sound absorbing diffusor device wherein the surface designed to face the sound source includes a plurality of sound absorbing wells of equal widths but different depths separated by thin sound absorbing dividers. The depths of the individual wells are based upon the quadratic-residue number theory sequence which is used in acoustic design. The wells are covered with an open weave fabric adhered thereover which fabric is specifically chosen for its ability to allow sound to pass therethorugh to the wells and dividers. Tests performed on the inventive sound absorbing diffusor have revealed significant reduction in sound levels of reflected sounds over that which would accrue from a flat absorptive panel.