目前能找到的最新的国际标准为ISO 2969-2015,这个是电影院标准;(从标准中可以看出,影片制作也越来越变态,5HZ都做进去了)
4.3现代音轨上低频效果声道的带宽从5 Hz扩展到120赫兹。 从大约25Hz到120Hz需要线性重低音扬声器响应。该
120赫兹音轨切断非常陡峭,因此合适的低音扬声器需要上面几乎没有响应125赫兹。 有关低音炮调节的信息,请参阅ISO 22234:2005。
许多房间在低频效应通道内具有一个或多个主要共振频率带宽。 如果没有阻尼,这可能导致每次特征性的低频“振铃”
音轨包含低频信息。 大多数影院处理器至少有一个用于低音炮带通的参量均衡器。 调整后,之间的反应25 Hz和120 Hz应平坦至±3 dB。
4.3 The bandwidth of the low-frequency effects channel on a modern soundtrack extends from 5 Hz
to 120 Hz. A linear sub-woofer acoustic response is desirable from approximately 25 Hz to 120 Hz. The
120 Hz soundtrack cut-off is extremely steep, so a suitable sub-woofer need have little response above
125 Hz. For information on subwoofer adjustment refer to ISO 22234:2005.
Many rooms have one or more dominant resonant frequencies within the low-frequency effects channel
bandwidth. If not damped this can lead to a characteristic low-frequency “ringing” every time the
soundtrack contains low-frequency information. Most cinema B-chain processors have at least one
parametric equalizer for use within the sub-woofer bandpass. After adjustment, the response between
25 Hz and 120 Hz shall be flat to within ±3 dB.