About Analog Audio Levels
There are six basic kinds of analog audio levels found on most equipment:
 Microphone level: Around 50 or 60 dB less than line level. When you use a
microphone, the level is very low, requiring a preamplifier to raise the signal to line
level before it can be recorded or processed. Most audio mixers, cameras, and
professional portable recording devices have built-in preamplifiers.
 Instrument level: Between microphone and line level, around –20 dBV or so. Guitars
and keyboards usually output at instrument level.
 Line level (consumer): Consumer line level is output at –10 dBV.
 Line level (professional): Professional line level is output at +4 dBu (or dBm in older
equipment).
 Speaker level: This signal varies considerably depending on the amplifier used, but it
is very strong compared to the others because it is used to drive speakers.
 Headphone level: This signal is like speaker level, but much lower. The sole purpose of
this signal is to drive stereo headphones.