Using the Kanto YU4 powered bookshelf speakers is a breeze. First, connect the speakers to a power source using the provided power supply. Then, you can choose your input method. For vinyl lovers, use the built - in phono preamp to connect your turntable with the RCA L/R with Phono Switch Inputs. If you want to stream music from your phone or other devices, pair them via Bluetooth with aptX technology. You can also use the 3.5mm AUX jack or the 2x Optical links. The single - knob control on the front makes basic adjustments easy, but for more detailed settings like bass, treble, and balance, use the included remote control. You can even connect a subwoofer to the subwoofer output for extra bass. When it comes to maintenance, keep the speakers in a dry and clean place. Avoid exposing them to extreme temperatures or humidity. If there's dust on the speakers, gently wipe them with a soft, dry cloth. Remember, all open box / b - stock items are final sale, so make sure to check the product thoroughly upon arrival.