Abstract: In order to obtain for electrodynamic loudspeakers, on the one hand, the energy-favorable acoustical enhancement by the bass reflex principle and, on the other hand, to be able to use the motional control of the diaphragm of the electrodynamic loudspeaker by controlling such by means of an amplifier exhibiting negative output impedance, it is proposed to compensate the thus resulting unfavorable frequency characteristic by a forwardly connected circuit which generates an inverse characteristic with respect to the unfavorable frequency characteristic.

Abstract: In a loudspeaker with a number of speaker units, each connected across one power amplifier to a diplexer, the power amplifiers having negative source impedance (-R.sub.1) are utilized. The diplexer includes an adder circuit and a filter connected thereto. The power amplifiers with negative source impedance reduce the linear distortions to such an extent that the use of modern diplexers is possible and further measures for reducing nonlinear distortions are appropriate.