A muffler for attenuating acoustic noise in a gas flow which includes a casing having an inlet and an outlet, such that the gas flow passes through the casing from the inlet to the outlet. The muffler also includes an acoustic trap disposed within the casing and which spans the distance between opposing top and bottom walls of the casing. The acoustic trap further comprises a first arcuate deflector having a concave frontside surface configured to direct the gas flow from the inlet through a first segment of an expanding spiral revolution, and one or more second arcuate deflectors which are radially offset from the first arcuate deflector and configured to direct a portion of the inlet gas flow through a remainder segment of the expanding spiral revolution.