Audio mixers with built-in power amplifiers (referred to as powered mixers or mixer-amps) are a convenient option for small to medium sound reinforcement systems. You simply connect the main outputs directly to speakers. The mixer section can range from quite basic with only a few mic/line imputs and minimal EQ and level controls (often no separate GAIN or TRIM) to mid range multi-channel systems. Powered mixers will often have additional built-in components such as Graphic Equalisers (GEQ) and digital effects processors(FX) and switches or connectors that allow the mixer and power amplifiers to be configured as separate components. This means that you can use the built-in amps for foldback speakers (for example) and connect the mixer outputs to external higher powered amplifiers and speaker systems (or powered speakers). See also - Audio Mixers (non-powered)