Applications of DSP for sound reproduction improvement

Today and tomorrow’s audio and video, portable audio and multi-media applications put increasing demands on sound reproduction techniques. On one hand there is a need for reductions in both cost and size, on the other hand we wish to enhance the experience of the user beyond today’s possibilities. A good sound reproduction system is in general in conflict with the boundary conditions for consumer products both by size as well as by price requirements. A possible way to ease these conflicts is to enhance the reproduction and perception of sound for listeners by exploiting the combination of psycho-acoustics, loudspeaker configurations and digital signal processing. Various examples will be given, such as increasing the perceived bass response of loudspeakers, and increasing the number of loudspeaker channels (converting stereo to multichannel sound). When multichannel reproduction through loudspeakers is not a viable option, the same percept can be simulated over headphones. This method, using active noise control principles, is discussed as well. PART 1: TWO-TO-FIVE CHANNEL SOUND PROCESSING