US Patent 10277978 Speaker device

The speaker device includes a cylindrical main body, a sound receiving portion, plural speaker units and at least one passive radiation plate. The cylindrical main body includes a top portion and a bottom portion. The sound receiving portion disposed on the top portion of the cylindrical main body. The speaker units are disposed within the cylindrical main body. The exports of the speaker units face the directions extending radially outward from an axial center of the cylindrical main body respectively. Each of the speaker units outputs a voice signal. The passive radiation plate is disposed on a surrounding surface of the cylindrical main body, and located between the speaker units and the bottom portion of the cylindrical main body. The passive radiation plate is driven to produce resonance with the air within the cylindrical main body, which is vibrated by the vibration of the voice signal.