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#X text 326 515 updated for Pd version 0.39;
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#X text 415 456 --- 0.02 sec ---;
#X text 36 41 Many synthesis algorithms and transformations can have
outputs with a zero-frequency component (commonly called DC for "direct
current"). These are inaudible and sometimes cause distortion in audio
output devices \, or when converting to fixed-point soundfile formats.
It is often desirable to filter an audio signal to remove its DC component.
, f 65;
#X text 36 137 The simplest way to do this is to use a one-pole low-pass
filter \, tuned to a low frequency such as 3 Hertz \, and to subtract
its output from the original. This difference is called a one-pole
\, one-zero high-pass filter \, and it is used so often that Pd provides
one in the "hip~" object., f 65;
#X obj 71 263 +~ 1;
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#X text 134 400 high-pass filter;
#X floatatom 110 364 5 0 0 0 - - -;
#X msg 110 289 0;
#X text 155 238 sinusoidal test signal;
#X text 117 263 add "DC";
#X text 148 289 zero for no filtering;
#X msg 120 312 3;
#X text 155 313 3 (or so) to remove DC;
#X text 160 337 higher frequencies affect;
#X text 202 351 the audible part of;
#X text 202 367 the signal as well.;
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#X msg 128 337 220;
#X text 102 9 ONE-POLE \, ONE-ZERO HIGH-PASS FILTER;
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