Self-powered speakers require a Pre-amp to boost the phono signal to a line-level. Many modern turntables come with a built-in switchable pre-amp. Usually the switch to turn on the pre-amp is either on the back of the turntable, or underneath the platter. The switch is most commonly labeled Phono/Line, it will need to be in the Line position. To find out if your turntable has a built-in pre-amp please refer to the owner’s manual, or contact the manufacturer.