The sound level is the
volume at which a
recorded effect, or
signal from a
microphone or other
source is at when it comes out of the
speakers. There are often a series of
faders that the
signal has to pass before coming out of the other end of the
sound desk - these all affect the eventual
level of the
sound.
The level on a
fader is normally marked between -
infinity, and +10 dB - on a
logarithmic scale. If the
fader is at 0 dB, then the
signal will not be changed. If the
fader is higher than 0, then the
signal will be boosted, and if the
fader is lower than 0, it will be decreased.
The dB change is additive - so, if a
signal goes through one
fader which
modifies it by -10dB, and then through the
master fader which
modifies it by -10dB, then that is the same as going through the first at -20dB, and the
master at 0dB. (This may seem
logical, but don't forget that on the physical
fader, the distance between 0db and -20db is less than twice the distance between 0db and -10db)
If you're after any other theatre tech information, then do take a look at '
Everything you ever wanted to know about theatre tech, but were afraid to ask'