POWER ADAPTER HAVING A SPEAKER FOR AN ELECTRONIC DEVICE

A power adapter for an electronic device, such as a notebook computer, includes a speaker to generate low audio frequencies, such as below 150 Hz. The speaker can be mounted in a variety of arrangements, i.e. closed-box, bass-reflex, or a more intricate shape which adds resonance (poles and zeros) to the acoustic filtering properties of the enclosure. An exemplary bass-reflex mounting includes a driver with resonance at 140 Hz, a chamber size of 7.74 in.sup.3 and a port determined by Thiele-Small equations. This gives a low frequency response beginning at 70 Hz. This low frequency component is combined in free space with the higher frequency components emanating from the portable electronic device's internal speaker(s). The audio signal connection can be made when the AC adapter is connected to the notebook computer by using two additional wires in the power cord. Since users generally carry their AC adapters with them, they can enjoy full harmonic sound without taking anything extra along. Alternatively, the AC adapter and electronic device can contain additional circuitry to provide wireless paths for either the power distribution path or audio interface or both.