| 摘要 |
<p>The hi-fi loudspeaker structure includes a tradditional electro-dynamic speaker mechanism mounted in the front panel of a casing. The casing includes a number of interconnecting chambers so that the resonant frequency of the assembly is higher than that of the passband of the loudspeaker (greater than or equal to 15,000 Hz). The chamber immediately behind the loudspeaker communicates with the next chamber by a number of small pipes of flexible plastic. These have length and diameter chosen to make it possible for hypersonic waves to be transmitted, the sum of their cross-sections being related to the radiating area of the loudspeaker. The pipes are perforated along their length by small holes to tune them to more than 20kHz.</p> |
