Do I need an extra cable to connect my speaker to an external device? Published on 2017-02-28 There is no need for extra cable. Depending on models, the speaker is already equipped with 3.5mm audio-in connection or USB connection. If the speaker comes with the 3.5mm audio-in cable, connect the cable to the headphone socket on the external device If the speaker comes with the USB cable, connect the cable to the USB socket on the computer