Amplified speaker contains a 50 watt peak audio amplifier. Use by itself or connect to the passive speaker for larger sound coverage using the 1/4" Left and Right output connectors. When using as a PA you have flexibility for three microphone selections. 1/4" dynamic, 3.5mm condenser or 3.5mm wireless connectors. As an amplified audio speaker, plug in any audio source, iPod / MP3 or CD player into the 3.5mm stereo connector. A 3.5mm stereo output connector is also included. Control speaker output with the separate volume control the microphone and a separate volume and tone control for the line in audio source.