Basic TV Technology, 4th Edition

Different kinds of equipment can be used together.

Combining Audio Components

Line and Mic Levels

Every piece of audio equipment except for microphones produces a very strong signal. This strong signal is usually called line-level or a high-level signal. Microphones create their own electricity and as a result create very weak signals. Mic-level or low-level signals may be 40 to 60 dB weaker than line-level signals. (Refer to the section on signal-to-noise ratios for a discussion of the dB scale and how it works.) If you take the output of a microphone and plug it into an input designed for line levels, you will hear no sound out of the microphone. If you take a line-level output and plug it into a mic-level input, the line-level signal will ...