RPG is an acoustic treatment manufacturer based in Passaic, New Jersey, best known for pioneering commercial sound diffusion based on number theory. The company was founded in 1983 by physicist Peter D'Antonio after he encountered Manfred Schroeder's research on reflection phase grating (RPG) diffusors, which gave the brand its name. Its 1987 QRD 734 — a quadratic-residue diffusor — was the first commercially produced sound diffusor and remains a reference design in studio and performance-space acoustics.

The product range spans diffusion, absorption, and hybrid panels, including the Skyline two-dimensional primitive-root diffusor, the Abffusor sound-absorption phase-grating panel, the BAD Panel (Binary Amplitude Diffsorber/Flatffusor) hybrid absorber-diffuser, and lines of wood and gypsum-fiber treatments such as the Perfecto micro-perforated panels and Clearsorber transparent acoustic systems for glass surfaces.

RPG products appear in recording and broadcast studios, concert halls, houses of worship, theatres, and large public spaces, with installations including Jungle City Studios in New York, LaGuardia Airport, and Hendrick Motorsports headquarters. D'Antonio's work on diffusor design is widely cited in the architectural-acoustics literature, and the QRD form factor he commercialized has become a visual and sonic shorthand for diffusion in project and professional studios alike.

RPG has 2 products cataloged on Equipboard, including Multi-Effect Plugins and Acoustical Treatments.