PA Systems at Idaho Audio Visual
The 6 Principles for Choosing a PA System
1. Like any sound reinforcement system, a PA system – or Public Address system – has three components:
- A pickup device (such as a microphone) to convert sound waves into an electronic signal
- An amplifier to boost the weak signal produced by the pickup to a level that can power a speaker
- A loudspeaker to convert the electrical impulse from the amplifier back into sound waves
2. Power (decibels) requirements, increase for larger audiences, noisy environments or outdoors. Power is the chief consideration when choosing a PA system. As the size of your event and audience increases, so do your power requirements. It is therefore useful to divide PA systems into categories based on their Wattage and the power of their amplifier.
If you're using the PA system for sound reinforcement at outdoor events, for example, sound reflections (and therefore the perceived volume of the PA system) decrease – and the amount of Wattage you need increases. Similarly, an auditorium with high ceilings requires far more amplification than a small conference room.
3. The Purpose of your PA system drives its requirements, i.e., Music or Voice. If you intend to amplify music, as well as speech, your PA system requires some additional capabilities:
- Music amplification requires a system that covers a wider range of audio frequencies than speech.
- Music reproduction requires more wattage. Since music contains a wider frequency spectrum than speech, power needs for music can more than double.
- Music sounds best in stereo. While a mono system may sound great in the relatively narrow range of speech, the complexity of music is better served by natural sounding stereo.
4. Speakers, will be either active or passive. Active speakers will not require additional amplifications where passive speakers will. This is critical in what you connect to the speakers. The number of speakers and the placement of the speakers at the venue can make a major difference in how the sound is received by your audience.
5. Mixers and Amplifiers; any time you have more than one input for sound or more than one speaker, you will need a mixer, this will prevent over powering the speakers with too much signal. If you need a line for input or output to attach portable digital devices like computers or iPods the mixer will accommodate this also. Then too, for multimedia and other presentations involving music, it's important to have a line input to plug in your CD or other media player
Mixers will equilibrate (by digitizing) the difference of a line or microphone signal. Each input will generally have a different sound level, and a mixer will compensate for this difference.
It is strongly recommended that an experienced technician help operate this equipment.
6. Quality of Sound, not all sound system that uses 500 watts of power sounds the same.
