You can pair two WONDERBOOM 2 together to double the sound. You can also pair it with 1st generation WONDERBOOM. To pair WONDERBOOM 2 with another WONDERBOOM or WONDERBOOM 2, PRESS AND HOLD the center button on both speakers at the same time until you hear a pairing tone. You will hear another tone to confirm pairing is successful. And music will be playing on both speakers.