Tapped Delay Line (TDL)

A tapped delay line (TDL) is a delay line with at least one ``tap''. A delay-line tap extracts a signal output from somewhere within the delay line, optionally scales it, and typically sums with other taps to form a TDL output signal. A tap may be interpolating or non-interpolating. A non-interpolating tap extracts the signal at some fixed integer delay relative to the input. Thus, a tap implements a shorter delay line within a larger one, as shown in Fig.2.18.

Figure 2.18: A delay line with one tap.

Tapped delay lines efficiently simulate multiple echoes from the same source signal. As a result, they are extensively used in the field of artificial reverberation.

• Example Tapped Delay Line
• Transposed Tapped Delay Line
• TDL for Parallel Processing
• General Causal FIR Filters