Abstract: Surround sound systems commonly produce, in addition to a surround channel, left, right and center channels. An apparatus is provided for connection between the left, right and center channels to enable the balance between the center channel and the left and right channels to be adjusted. It enables the level of the center channel to be reduced and the center channel to be correspondingly redistributed to the left and right channels to create a phantom center channel from those left and right channels. The degree to which the center channel is reduced in level, and extent to which the center channel is redistributed to the left and right channels are both variable.

Abstract: A method and circuit for achieving reduced signal distortion in a filtered signal. The method involves connecting an input signal to a main path and a side chain path. The signal carried on the side chain path is then processed to generate a complementary signal which, when combined with the input signal carried by the main path, will produce a target output signal. The circuit includes a side chain processing stage, having a filter stage and a first subtraction stage, and a final processing stage. The input signal is carried on the side chain path to a filter path and a processing path. The signal carried on the filter path is filtered through the filter stage to generate a first filtered signal. The first filtered signal is then subtracted from the input signal on the processing path at the first subtraction stage to generate a complementary processed signal. The complementary processed signal is then subtracted from the input signal on the main path to generate the target output signal.