A transducer that converts electrical energy into acoustical energy. The most common type of loudspeaker today is the dynamic loudspeaker which has a resonant frequency, the frequency at which it will vibrate naturally if perturbed. The resonant frequency, also called the natural frequency, will be near the lowest frequency that the speaker will reproduce well, and is that frequency at which it is easiest to move the cone (the output from the speaker will be at a maximum). Damping must be added to a speaker system in order to reduce this peak in response.