Notches occur in the spectrum as a result of destructive
interference.
Recall that delaying a sine tone 180 degrees (1/2 a cycle) and
summing with the original will cause the signal to disappear at the
output.
Figure 13:
Complete destructive interference.
 |
If a sinusoid has a frequency of
, then a delay of 1/2
cycle corresponds to a delay of

seconds
or

samples
``Music 206: Delay and Digital Filters I''
by Tamara Smyth,
Computing Science, Simon Fraser University.
Download PDF version (filtersDelayI.pdf)
Download compressed PostScript version (filtersDelayI.ps.gz)
Download PDF `4 up' version (filtersDelayI_4up.pdf)
Download compressed PostScript `4 up' version (filtersDelayI_4up.ps.gz)
Copyright © 2020-01-14 by Tamara Smyth.
Please email errata, comments, and suggestions to Tamara Smyth<trsmyth@ucsd.edu>