Page 153 - The Master Handbook Of Acoustics

128 CHAPTER SIX

Noise reduction
Image enhancement

Stereo synthesizer

This very brief treatment of digital signal processing has skipped
over such vital aspects as aliasing, the multiplier/accumulator, sam-
pling rates, quantization levels, etc.

Application of DSP to Room Equalization

The application of digital signal processing to the loudspeaker-room-
listener problem is currently being pursued vigorously. Huge errors
are common in both the room and the loudspeakers. The problems of
the listener are primarily the great differences in sensitivity between
listeners.
The basic idea is to measure the frequency and phase response of
the speaker/room combination and apply an equalizer that perfectly
compensates for the defects. This is a very complicated operation, but
theoretically possible through the great potential of digital signal pro-
cessing. One problem to be solved is how to generalize the solution
based on data picked up at one point in the room. There are many
other problems but the next decade should bring major advances in
this field.

Endnote
1 Burkhard, Mahlon, Filters and Equalizers, Chapter 20, Handbook For Sound Engineers,
Glen Ballou, Ed., Carmel, IN, Howard W. Sams Co., 2nd Edition (1987).