Provided herein is a loudspeaker system utilizing one or more ducted slot ports. In various embodiments, a ducted slot port may incorporate an acoustic low pass filter, such as a bend in the airflow path, to control midrange leakage. A ducted slot port may also minimize standing waves within the port duct and control turbulent port noise, such as by varying its cross-sectional area substantially continuously and symmetrically along the port duct's entrance-exit axis.