Patent ID: 7520370

Claim:
A combination acoustical energy diffuser and absorber, comprising an acoustical energy diffuser made by a method comprising the vacuum forming of at least one sheet of pliable material in conformity with a shaped template and the subsequent fixing of the resulting shape of said material to produce an acoustically reflective surface having a front face and a rear face, wherein said acoustically reflective surface has a corrugated surface topology described by a plurality of alternating crests and wells, wherein the width of each individual well increases continuously from its minimum found at the bottom of the well to its maximum found at the top of the well, wherein the deepest points of all individual said wells are all coplanar with one another, wherein the depths of successive said wells of said corrugations relative to one another are in the same ratios as are those successive numbers determined through the calculation of a number theory sequence relative to one another, wherein said number theory sequence is a quadratic residue sequence, and further comprising at least one Helmholtz resonator acoustical energy absorber contained within a well on said rear face of said acoustically reflective surface and attached to said rear face of said acoustically reflective surface, said at least one Helmholtz resonator acoustical energy absorber comprising a cavity and at least one orifice allowing atmospheric communication between the interior of said cavity and the external environment, wherein at least one of said at least one Helmholtz resonator absorbers has an adjustable bandwidth.