Abstract: A circuit for operating loudspeakers includes a first, second, third and fourth loudspeaker circuit, having one input each for injecting a signal and one output each for connecting a loudspeaker input. The loudspeaker circuits are designed to amplify the injected signal and to provide the amplified signal at the outputs thereof. The loudspeaker circuits can, for example, be used for a 2.1 sound system. The three channels for a 2.1 sound system can be implemented by an amplifier circuit with four loudspeaker circuits, one loudspeaker circuit each being required for the two stereo channels left and right. A subwoofer channel can be driven differentially by two loudspeaker circuits. The stereo channels are, by contrast, only still connected to one loudspeaker circuit each, and so the stereo channels require at least one further common ground cable.