A mobile phone (1) includes a casing (10) containing a printed circuit
board (28) and an antenna (29) therein; and a speaker set (20) is
disposed between the printed circuit board and the antenna. The speaker
set includes a hollow shell (21) including a first chamber (220), a
second chamber (230) and a third chamber (240) isolated from the second
chamber, and a loudspeaker (25) accommodated in first chamber of the
shell and dividing the first chamber into a front chamber (224) and a
rear chamber (223). The front chamber communicates with the second
chamber, whilst the rear chamber communicates with the third chamber.