Acoustics: Sound Fields, Transducers and Vibration, 2nd Edition

6.2. Construction [2]

A cross-sectional sketch of a typical loudspeaker drive unit is shown in Fig. 6.1. The diaphragm (1) is a cone made from a suitably light and stiff material, although most of the stiffness comes from the fact that it is curved. In the center is a dust cap (2), which guards against metallic dust fouling the magnetic gap and prevents sound from the back of the diaphragm leaking through to the outside world. If the loudspeaker were mounted in a bass-reflex enclosure, such leakage could seriously reduce the Q of the port resonance. Attached to the top of the cone is a coil former on which the coil (3) is wound. This coil is located in the gap of a magnetic path, comprising a pole piece (4) and pole plate (5), where the magnetic ...