Stackable loudspeakers

An audio system comprising

• first and second loudspeakers, each comprising:
• a housing comprising a plurality of walls which together define an acoustic cavity;
• an electro-acoustic transducer mounted to a front wall of the housing;
• and
• keyed features,
• wherein a motion axis of the electro-acoustic transducer is offset from a centroid of the front wall;
• wherein the first and second loudspeakers are configured to be stacked on top of one another in a physical first configuration with respect to each other such that the first and second loudspeakers radiate acoustic energy to produce an omnidirectional radiation pattern;
• and in a physical second configuration with respect to each other such that the first and second loudspeakers radiate acoustic energy to produce a cardioid radiation pattern, wherein according to one of the physical first or second configuration the front wall of each of the loudspeakers face in the same direction and in the other of the physical first or second configuration the front wall of each of the loudspeakers face in opposing directions, and
• wherein the respective keyed features of the first and second loudspeakers do not interlock and thereby inhibit stacking when the first and second loudspeakers are in a first orientation relative to each other, and interlock to allow stacking when the first and second loudspeakers are in a second orientation relative to each other.