PORTABLE LOUDSPEAKERS AND CONVERTIBLE PERSONAL AUDIO HEADPHONE/LOUDSPEAKERS

The invention provides, in some aspects, an audio headphone suitable for conversion to a loudspeaker. The device includes one or more earcups, each having a concavity that includes first and second volumetric regions and a wall that seals the regions from one another. The first volumetric region defines a space that receives a pinnea when the headphone is worn by a user, and the second volumetric region has one or more active drivers (a/k/a "speakers"). The wall includes one or more active diaphragms of those one or more active drivers. Those diaphragms generate front waves directed into the first volumetric region and back waves directed (back) into the second volumetric region. A passive radiator that is elastically mounted in the wall passes to the first volume from the second volume at least a portion of back waves generated by one or more of the active diaphragms. The invention provides, in other aspects, portable loudspeakers constructed in a manner of the earcups described above.