ABSTRACT
This chapter talks about the digital signal processing filter algorithms and develops some digital delays for our delay plugin. The answer to the problem of long delay lines is called circular buffering. The digital delay effect or digital delay line (DDL) consists of a long buffer for storing audio samples. A more useful version of the basic DDL combines the output of the delay line with the current input. The delay line output is called the wet value and the unprocessed audio input is the dry value. When the delay time is long, the ears will hear the delayed signal as an echo. When the delay time becomes shorter than about 30 mSec, the ears cannot resolve the echoes as independent events in time; instead they smear together with the dry signal and this produces a noticeably “filtered” output rather than echoes. The ping-pong delay crosses both the input and feedback paths to the opposing channel.
