The audio power amplifier for professional use is one of the most important device for amplify signals coming from a normal preamp or mixer. The power amplifier provides, trough its transformers and circuits, the right supply of electrical current to provide to the speakers system.
More the audio power required is high, more many imperfections could be evident and heard.
For this reason in the audio professional work, the technical users are very careful to choose this devices.
When the power they need is high it's possible to use a single channel power amplifier (mono) or sum the power (in bridge mode) of a two channels power amplifier, using in this way only a output connector to connect just one speaker exploiting
the maximum power available.