The amplifier receives the combined or mixed signal from
the mixer.
The amplifier is the last component in the sound system before
the speaker. Generally, the sound signal progresses through the
sound system as follows:
Digital Delay (only for remote speakers that must be
time-aligned with the main speakers)
Cross-Over (only in the case of bi-amped or tri-amped speaker
systems or a sub-woofer)
Amplifier
Speaker(s)
The amplifier supplies the power to drive the
speakers.
Most speaker systems, especially lower power speakers only
require a single amplifier. However, some speaker systems are
designed to work bi-amped or tri-amped. In the case of a bi-amped
system, two amplifiers are needed, one for low frequency sounds
and one for high frequency sounds. In the case of tri-amped,
three amplifiers are needed for low, midrange, and high sounds.
If a sub-woofer is used for very low sounds, another amplifier is
needed for it.
Separate amplifiers are needed for the Main System, remote
speakers (if required), and the Monitor System.
When multiple monitor mixes are used, each mix requires its
own amplifier.
In order for an amplifier to make the sound twice as loud, it
must supply four times as much power. For example, it takes a 400
watt amplifier to be twice as loud as a 100 watt
amplifier.
Always use an amplifier capable of supplying more power than
you need. Distortion increases dramatically when an amplifier is
operated at its maximum power. Having plenty of "head room" or
reserve power reduces the chance of distortion.
It is important that an amplifier have very low background
noise. Even a small amount of "hiss" can be very
objectionable.
The power rating of the amplifier and the speakers must be
similar to reduce the chance of damaging the speakers.
