Brochure

V
Ceiling
Speaker
Ceiling
Speaker
In case the emergency broadcasting speaker (90db SPL) is installed at intervals of 25m, listening the sound at the intermediate
position between speaker and speaker will get smaller about 14times (22db) than listening the sound at the bottom of speaker.
It is difcult to understand the noise as the sound is smaller than ambient noise(70dBA SPL)
Therefore, the spacing of the speaker installation should decrease under 15m to deliver the exact information.
The speaker for emergency broadcasting requires the higher
sound pressure when considering ambient noise increases
as growing the ventilation system lately and ambient noise
grows at emergency state.
The existing 3W speaker can't provide the appropriate
sound pressure as the clear broadcasting is possible by
making over 6dB of sound pressure comparing ambient
noise (70dBA SPL)
So the existing broadcasting is possible by installing the
speaker, which is possible to make the output of over 120W.
It was used and designed with matching the volume of amplier and speaker output as the past PA system are consist of mainly
speech broadcasting such as a emergency broadcasting and announcement. But the recent PA system is used for mainly BGM
music in addition to speech broadcasting.
Therefore, it requires the higher output of amplier and speaker than the existing amplier output to make a good quality of
music broadcasting and clearer announcement. In comparision with the volume of the speaker output, the output of amplier
should be designed minimum over 2 times of the output to make the sound quality and sound articulation.
The spacing of the speaker installation
The spacing of the ceiling speaker installation
The combination between speaker and amplier
1.5m
Speaker
GOOD BAD
Speaker Speaker
4m 4m
8m (less than15m)
25m (Maximum length)
3W Output 12W Output
70dB
76dB
GOOD
BAD
70dB (Indoor noise standard)
1.5m
Speaker
GOOD BAD
Speaker Speaker
4m 4m
8m (less than15m)
25m (Maximum length)
3W Output 12W Output
70dB
76dB
GOOD
BAD
70dB (Indoor noise standard)
12W x 13 300W
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