Structure and Sound Pressure of BGM System Speaker

The basic structure of BGM system speaker, from input to output, is as follows:

1. Source equipment (microphone, CD, cassette tape, cable, etc.)

2. Mixer (preamplifier)

3. Signal Processing Equipment (Equalizer, Compressor, Limiter, etc.)

4. Power amplifier

5. BGM system loudspeaker

When designing the system, we usually choose the speaker which is suitable for the interior decoration or design. Loudspeaker is an important factor to determine the specifications of power amplifier and signal processing system. It has a rich variety and knowledgeable selection. Here we focus on the selection of speakers to illustrate the design techniques of BGM system.

When people hear more than two kinds of voices, if one of them increases, they will be unable to hear its voice (this phenomenon is called masking). Therefore, BGM is generally about 3dB larger than background noise level  ( Usually about 6dB is used for amplification)

1. Restaurants 65-70 dB

2. Department store counter floor 70-75 dB

3. CD Store 85-90 dB

4. Marbles line 90-95 dB