PAGING & Music Systems
These generally consist of a microphone, some source of music if required, an amplifier and speakers. Depending on the system use, the parameters will change.
• General paging does not require full range speakers however the speaker volume should remain low and the amount of speakers increased as audibility is affected by distortion. Generally used in Stations, Plants etc.
• Paging and background music.
Here the speakers should be of a higher quality with a wide audible range to cover both voice and music.
Paging systems can be configured in either a distributed 70volt system or 8 Ohm.
The 70volt system allows multiple speakers on the same pair of wires which cuts down on wiring requirements. The amplifier is set to send out a 70volt sound signal and each speaker has a transformer to convert the 70volts to the speaker. These transformers do degrade the signal and this system is not for the system which requires high fidelity sound.
The Ohm configuration usually called “Ohm” is calculated and wired to allow the required signal to go from the amplifier to the speaker without any intervening transformers. This removes the distortion caused by the transformers, however the wiring requirements are higher.
There are many types of intercom. The simplest form is a door with a call button and speaker to a station inside. Once the caller is identified, they can be buzzed in by the station.
Multi station units are available giving the option of talking and selecting between each station. These usually have a hands free module for answering.
Telephone-Intercom can be incorporated into a telephone system which can also have standard stations, outdoor calling stations and paging options.