Abstract: An active noise attenuation system (10) comprises a speaker (26) in communication with a flow body (78). The speaker (26) emits an output for attenuating noise from the flow body (78). A control unit (31) communicates with the speaker (26) and controls the output. A housing (14) has one volume (18) acting as a liquid storage chamber and another volume (22) acting as a speaker chamber.

Abstract: An injection molded screw retainer is employed on an air intake manifold system to retain screws which connect an active system body to a manifold lower assembly. The retainer is substantially “L-shaped” and includes a retaining portion and a substantially perpendicular attachment portion. The retaining portion includes a substantially hemispherical feature positioned substantially over the head of the screw. The oversized attachment portion is inserted within a pocket in the active system body. Ultrasonic energy applied by a sonic welding process slightly melts the outer surface of the attachment portion, creating a weld interference between the attachment portion and the pocket, securing the attachment portion within the pocket.