Be the Master of Ceremonies and the Disk Jockey at your next party; BBQ; camping trip; or family outing using this Bluetooth Party Speaker from Monoprice! This portable speaker system is designed to serve as both a music source and a PA system. It features an 8" woofer and 1/2" dome tweeter with a frequency response of 50 Hz ~ 20 kHz ±3dB . It is powered by a built in amplifier that can produce up to 50 watts. The speaker system is powered using either an AC power connection or a builtin rechargeable leadacid type powersports battery. When under battery power the amplifier can produce up to 18 watts. There are four primary methods of connecting to a music source: Bluetooth you can stream music from your smartphone or tablet to the speaker system using a wireless Bluetooth connection USB you can plug a USB flash drive with mp3 and/or wma files into the USB port SD/MMC Card you can plug an SD or MMC card with mp3 and/or wma files into the card slot Wired you can connect a line level input into the 3.5mm TRS jack or into the two RCA jacks Additionally; the system sports two 1/4" microphone jacks; so up to two people can take the stage to MC or sing along with the music. The system features three individual volume controls for the various inputs: MIC VOLUME controls the volume level of the two microphone inputs AUX VOLUME controls the volume level of the linelevel and Bluetooth inputs VOL+/VOL controls the volume level of the builtin mp3/wma player for the USB and card slot inputs Additionally; a single Master volume knob controls the final amplifier output level. All three input channels are simultaneously active and are mixed into the final output. Note that there are no special formatting or file organizational requirements for the USB and Card Slot inputs. You can have any number of individual music files; but are limited to a total of 999 directories/folders. The mp3 player will recognize music files in subdirectories up to 99 deep; but i