Usually, the background noise of office corridor is about 48-52 dB, and that of supermarket is about 58-63 dB, and that of busy section is about 70-75 dB. Considering that the scene may be very confused in the event of an accident, the background noise should not be estimated too low for the need of emergency broadcasting, even if the broadcasting service area is an office building. Therefore, as a general consideration, in addition to busy and lively places, background noise may be roughly regarded as 65-70dB (except in special cases). According to this calculation, the sound pressure level in the broadcast coverage area should be above 80-85 dB.
SejakPenceramah adress awam are usually distributed, the sound pressure level in the adress coverage area can be approximately considered as the contribution of a single public adress speakers
. Menurut teori elektroakustik yang berkaitan, tahap tekanan bunyi SPL di kawasan liputan pembesar suara mempunyai hubungan berikut dengan tahap kepekaan LM pembesar suara, kuasa P diberi makan kepada pembesar suara, titik pendengaran dan jarak r pembesar suara, dan sebagainya.
SPL=LM 10lgP-20lgrdB(1)
Tahap kepekaan pembesar suara cacar berkisar antara 88 hingga 93 dB, dan kuasa diberi nilai adalah 3 hingga 10 W. Dikira oleh 90dB/8W, tahap tekanan bunyi pada 8m dari pembesar suara adalah kira-kira 81dB. Sumbangan kumpulan bunyi tercermin awal tidak dianggap dalam pengiraan di atas. Dalaman, sumbangan kumpulan bunyi yang dicerminkan awal dan pembesar suara bersebelahan boleh meningkatkan tahap tekanan bunyi sebanyak kira-kira 2-3 dB.
According to the above approximate calculation, the ceiling loudspeakers can be arranged evenly at a distance of 5-8 m in a venue whose ceiling is not higher than 3 m. If only background music is considered and emergency broadcasting is not considered, the distance can be increased to 8-12 M. In addition, the design and installation code for fire accident broadcasting in mainland China (hereinafter referred to as "code").
Pada dasarnya tiada kumpulan bunyi reflektif awal di kawasan luar, dan liputan berkesan satuSpeaker alamat awam can only be taken as the lower limit calculated above. Since the lower limit corresponds to a very short distance, in principle, a sound column composed of multiple speakers should be used. The sound pressure level can be increased by 3dB for every doubling of the signal power to the speaker group (such as the sound column) provided that the group is acceptable. From 1 to 2 is double; from 2 to 4 is double. In addition, the sound pressure level will decrease by 6 dB for every doubling of distance. According to the above rules, it is not difficult to calculate the configuration distance of outdoor sound column.
Mesyuarat kelulusan Standard kebangsaan yang diadakan di BeijingJuly 19, 2019Mesyuarat kelulusan Standard kebangsaan yang diadakan di BeijingThe kelulusan mesyuarat piawaian StandardTechnical kebangsaan sistem alamat awam engineeringis diadakan di Beijing pada 16 julai 2019. Xue Chang...view
Memandu bunyi ke hadapan: kemajuan dalam teknologi penguat PA profesionalJuly 6, 2023Dalam dunia audio, penguat PA profesional memainkan peranan penting dalam menyampaikan tetulang bunyi yang kuat dan jelas. Penguat ini telah datang jauh dari segi kemajuan teknologi...view
EN
ar
bn
fr
ms
de
th
id
hi
pt
ru
es
