Abstract: A wave interference silencer includes a sealed envelope having an inlet and an outlet in communicaton with an exhaust flow volume therebetween which is divided into a plurality of compartments by spaced apart intermediate wall portions each having an exhaust opening therein to define a continuous exhaust flow path from the inlet to the outlet ends of said envelope and wherein each compartment further includes a flow diverting baffle to prevent linear flow of exhaust through said exhaust flow openings and to define a first and second curvilinear flow path around each baffle each having an acoustical flow path length to produce wave interference silencing of a predetermined noise frequency within each compartment without obstructing exhaust flow between the inlet and outlet of the envelope.

Abstract: A low cost wave interference silencer including an enclosure having an inlet and an outlet with a direct bypass communication therebetween with a first acoustical length and further including a plurality of flat fin components enclosed between wall segments of the enclosure to define a plurality of series-connected flow paths arranged in spaced parallelism and including segments in reverse flow relationship to define a second flow path between the inlet and the outlet having an acoustical length greater than that of first acoustical length to produce a phase shift of a sound frequency within the exhaust flow between the inlet and the outlet and a resultant wave interference attenuation thereof.

Abstract: A wave interference silencer assembly is disclosed for attenuating low frequencies without extension of the length of an inner tube component of a helical path wave interference silencer having a pair of exhaust flow tubes of equal length. A twisted ribbon component is twisted along its length to define an acoustical path length in one of the tubes longer than the length of the tube to produce attenuation of lower frequencies while retaining substantially equally divided exhaust volume flow through the first and second tubes.