Micnivå

Micnivå, or microphone level, is the electrical signal level produced by a microphone before significant amplification. It is typically very small; in professional audio, mic level is usually between -60 dBV and -40 dBV, roughly 1 millivolt to 10 millivolts RMS. The exact level depends on the microphone type and the acoustic source. Because it is a weak signal, it must be boosted by a microphone preamplifier (mic pre) to line level for recording, mixing, or live sound.

Most microphones use a balanced connection, commonly an XLR, to reduce noise. Dynamic microphones tend to have lower output than condenser microphones, though both operate at mic level. Condenser mics require phantom power (commonly 48 V) delivered through the same XLR cable when their circuitry calls for it.

The mic preamp presents a relatively high input impedance to the microphone, typically around 1.5 kΩ to 2 kΩ or higher, to minimize loading of the source. After gain, the signal is brought to line level, which is much higher (about 1 V RMS for professional gear; consumer equipment may use -10 dBV).

Gain staging is important: set the preamp gain so the signal is strong and clean without clipping; for very loud sources, use a pad or a lower-output microphone.