A muffler assembly for an exhaust system is in fluid communication with a collector via an exhaust conduit. The muffler assembly includes a primary pipe, a valve, a secondary pipe, a tuner tube and a bleed port. The primary pipe extends through an enclosed volume of the muffler. The valve is operable to restrict flow through the primary pipe. When a standing wave is present, a resonance length is defined by a length of the exhaust system that extends from the collector to the valve. The tuner tube includes an open tuner tube end in fluid communication with the primary pipe and a closed tuner tube end. The tuner tube has a tuner tube length that is substantially one-quarter of the resonance length. The bleed port is formed in the primary pipe, allowing fluid communication with the enclosed volume, and positioned downstream from open tuner tube end.