How do I sync the Polk Omni SB1 Plus sound bar with its included wireless subwoofer?

Make sure that the sound bar is on, and there is sound present. Turn off the subwoofer via the power switch on the back. On the top of the sound bar, press and hold the Bass + and Bass - buttons until you hear a chime, then turn the subwoofer back on. Once it pairs successfully, you'll hear a second chime and then see two solid green lights on the back of the subwoofer.