Here's a simple mixer. It has six
input faders (lower left) so you could
mix together six different sound sources.
A
device that mixes two audio signals together is called
a "mixer." Pretty much a no-brainer
there.
Mixers
have two or more faders that will allow you to adjust
the incoming volume level of each audio source.
Sound
Mixing:
There's only one really important rule here--but it's
critical: At any given point in time, only ONE audio
source can be dominant. It can be voice, music, sound
effects, whatever--as long as only ONE is loud
(full volume). All others must be quiet (in the background).
In a given piece, the dominant audio source might change
several times. For example, the narration might stop
and then the background music would get louder and become
dominant. But at any given point, only ONE is full volume.
In
the example below, the music and narration are BOTH
dominant. It's a problem. The solution--fade the music
down.
To
the left is and example of how a mixer
might be used: In the example we have
two audio sources: music and voice-over.
If we mix them at the same level,
it quickly becomes clear that the
music is too loud and drowns out the
voice-over. So we use the mixer to
reduce the volume of the music until
it no longer drowns out the voice.
(Click PLAY triangle)
It's
not uncommon to have a mixer with
16 or 24 faders to control lots of
incoming audio, but the process is
the same as in this simple example.