signal processing Signal processing is an electrical engineering subfield that focuses on analyzing, modifying and synthesizing '' signals'', such as sound, images, and scientific measurements. Signal processing techniques are used to optimize transmissions, ...

, delay equalization corresponds to adjusting the relative phases of different frequencies to achieve a constant

group delay In signal processing, group delay and phase delay are delay times experienced by a signal's various frequency components when the signal passes through a system that is linear time-invariant (LTI), such as a microphone, coaxial cable, amplifier, ...

, using by adding an

all-pass filter An all-pass filter is a signal processing filter that passes all frequencies equally in gain, but changes the phase relationship among various frequencies. Most types of filter reduce the amplitude (i.e. the magnitude) of the signal applied to i ...

in series with an uncompensated filter. Clever machine-learning techniques are now being applied to the design of such filters.

References

Signal processing Digital signal processing {{signal-processing-stub