Abstract: A low-powered loud speaker is provided with one or more echo generators composed of an insulation tube, a first magnetic permeability element, a second magnetic permeability element, and an induction coil wound around the insulation tube. The first and the second magnetic permeability elements are engaged with the insulation tube such that the first magnetic permeability element is suspended, and that the second magnetic permeability element is induced to generate a magnetic attraction at such time when a sound frequency current passes the echo generator. The echo generator is thus capable of vibration twice the sound frequency, so as to simulate the echo effects.