Performance sound is produced with a muffler that includes a casing with front (5, 37), rear (7, 41) and side (3, 35) walls, first (9, 45) and second (11, 47) compartment walls each with a central passage (25, 28, 46, 48) and side circular passages (26, 27, 26, 27). The first compartment wall is spaced behind the exhaust gas inlet (6, 39). The second compartment wall is spaced in front of the rear wall. A first divider baffle (21, 21) divides one side passage in the first compartment wall into a plurality of passages, and a second divider baffle (23, 23) divides the second side passage in the first compartment wall into a plurality of passages. An elongate louvered tubular member (13, 13) between the first and second compartment walls receives exhaust gas from the first compartment and permits exhaust gas to exit into the second compartment. A third divider baffle (17, 17) divides a portion of the interior of the tubular member into four sectors so exhaust gas entering the tubular member is divided into a plurality of streams.