| 摘要 |
<p>PURPOSE:To realize linear phase speakers using the network of filter characteristics of specific secondary elements by generating specific phase delays in crossover frequency. CONSTITUTION:The low and high cut frequencies of filters are let to be fLH and fHL respectively and are selected near the crossover frequency of a speaker system and the thresholds of high and low range characteristics of the speakers themselves are let to be fLL and fHH respectively and are selected at fLL<<fLH thru fHL<<fHH and further if the polarity of the tweeter is so arranged to become opposite from that of the woofer, the overall characteristics G become G=GLL GLH-GHL GHH. Then, the sound pressures may be made approximately flat near the crossover frequency but the phase characteristics do not become linear and therefore a position delay of about 90 deg. is given at the crossover frequency. By giving such delay time, the linear phase speakers using the network composed of filter characteristics (+ or -12 dB/oct.) of secondary elements may be realized.</p> |
