Acoustic device having an electro-acoustic transducer mounted to a passive radiator diaphragm

An acoustic device, comprising:

• a first acoustic cavity that is substantially air tight;
• a second acoustic cavity that is substantially air tight;
• a first passive radiator comprising a first passive radiator diaphragm having a rear surface which is exposed to the first acoustic cavity;
• a second passive radiator comprising a second passive radiator diaphragm having a front surface which is exposed to the first acoustic cavity, and a rear surface which is exposed to the second acoustic cavity;
• and
• a first electro-acoustic transducer supported on the second passive radiator diaphragm,
• wherein the first electro-acoustic transducer is arranged such that a first radiating surface of the first electro-acoustic transducer radiates acoustic energy into the first acoustic chamber and a second radiating surface of the first electro-acoustic transducer radiates acoustic energy into the second acoustic chamber.