| 摘要 |
<p>A power adapter (16) for an electronic device (12), such as a notebook computer, includes a speaker (17) to generate low audio frequencies, such as below 150Hz. The speaker (17) 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 140Hz, a chamber size of 7.74 in<3> and a port determined by Thiele-Small equations. This gives a low frequency response beginning at 70Hz. This low frequency component is combined in free space with the higher frequency components emanating from the portable electronic device's internal speaker(s) (10). The audio signal connection can be made when the power adapter (16) is connected to the notebook computer by using two additional wires in the power cord (14). Since users generally carry their power adapters (16) with them, they can enjoy full harmonic sound without taking anything extra along. <IMAGE></p> |
