Multi-Channel Room Impulse Response Shaping - A Study

This paper addresses the usability of channel shortening equalizers known for data transmission systems for the equalization of acoustic systems. In multicarrier systems, equalization filters are used to shorten the channel´s effective length to the size of a cyclic prefix or the guard interval. In most applications the equalizer succeeds the channel. In acoustic systems, an equalizer is placed in front of a playback loudspeaker to generate a desired impulse response for the concatenation of the equalizer, a loudspeaker, a room impulse response, and a reference microphone. In this paper, we show that shaping the desired impulse response to a shorter reverberation time is more appropriate for acoustical systems than trying to exactly truncate it to a maximum length. Investigations are carried out using a multi-loudspeaker-multi-microphone system