Is Your Public Address System's Sound Clear

The voice notification in the public address system must can be understood by people, otherwise it is just noise pollution. Sometimes the unclear voice notification may also cause legal fallout.

How to use the public address system effectively:

1. Make sure that all installed amplified speakers have the same polarity to ensure that the given power has the highest SPL output.

2. Test whether each amplified speaker is in place. It can be tested by using a 19kHZ high-pass filter, so that it will not disturb the public.

3. Verify whether the number of amplified speakers connected together matches the specifications of the drive distribution amplifier. For this, you will need an impedance meter. Some impedance meters will provide a direct readout of the power of the connected speakers.

4. Verify the reverberation time of your environment. If necessary, let the architect or construction company be aware of the necessity of room treatment, and realize that the reverberation time depends on the frequency and should be measured in the entire voice frequency band.

5. Verify the distortion level of the electrical system and determine the damaged signal processor or amplifier. For this, you will need a pure sine wave blending distortion analyzer.

6. Know exactly which level your background noise is. If possible, you will need to adjust the PA audio system to 10 to 15dB above this level for transmission. For this, you need an SPL meter with averaging function. Remember that the sharpness will start to drop again at an absolute level above 90 decibels, because at such a high level, our ears will become less sensitive.

7. If the operator uses a PA system microphone to broadcast an evacuation notice, the STI-PA test should be performed with a calibrated audio signal source.

8. After you optimize all these moving points, you do not need to use the STI-PA instrument to finally measure the speech intelligibility. If operating properly, you will announce the 0.5 minimum requirement of the evacuation system at all test points.