100v Public Address Basics
Installing a PA System
Audio Principles & Theory
Miscellaneous
Public Address Information - 1
| Here is a simple system used for announcements: |
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| This comprises of a desk paging microphone, a mixer amplifier and a horn loudspeaker. When the press to talk switch is operated on the microphone, a message can be broadcast to the loudspeaker via the amplifier. |
| This system can be developed with more loudspeakers to cover a larger area, or alternative types of loudspeaker to suit different areas or locations, here is an example with horn and ceiling loudspeakers. |
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| There is a potential problem with multiple loudspeaker systems, in that wiring up multiple speakers to match them to amplifier outputs can be very complex and use a lot of cable. Additionally, it can be difficult to adjust the amount of volume required at any one particular speaker. To work around this, manufacturers came up with a solution by adopting transformers with multiple tappings for use in each loudspeaker. This high impedance distribution method solves the problem of series and parallel combinations and allows a speaker level to be changed up or down by changing the transformer setting. This system is commonly known as the 100v line system in the UK and Europe. |
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