<script type="text/x-red" data-help-name="AudioEffectFlange"> <h3>Summary</h3> <div class=tooltipinfo> <p>Originally, flanging was produced by playing the same signal on two synchronized reel-to-reel tape recorders and making one of the reels slow down and speed up by pressing on the flange of the reel (hence the name). This is a type of comb filtering, and produces a harmonically-related series of peaks and notches in the audio spectrum.</p> </div> <p>This flanger uses a delay line, combining the original voice with only one sample from the delay line, but the position of that sample varies sinusoidally.</p> <p>The effect can be represented as:<br> result = sample(0) + sample(dt + depth*sin(2*PI*Fe))</p> <p>The value of the sine function is always a number from -1 to +1 and so the result of depth*(sin(Fe)) is always a number from -depth to +depth. Thus, the delayed sample will be selected from the range (dt-depth) to (dt+depth). This selection will vary at whatever rate is specified as the frequency of the effect, Fe. Typically a low frequency (a few Hertz) is used. <h3>Audio Connections</h3> <table class=doc align=center cellpadding=3> <tr class="top"><th>Port</th><th>Purpose</th></tr> <tr class="odd"><td align="center">In 0</td><td>Signal Input</td></tr> <tr class="odd"><td align="center">Out 0</td><td>Flanged Output</td></tr> </table> <h3>Functions</h3> <p class=func><span class=keyword>begin</span>(delayBuffer, length, offset, depth, delayRate);</p> <p class=desc>Create a flanger by specifying the address of the delayline, the total number of samples in the delay line (often done as an integer multiple of AUDIO_BLOCK_SAMPLES), the offset (how far back the flanged sample is from the original voice), the modulation depth (larger values give a greater variation) and the modulation frequency, in Hertz. </p> <p class=func><span class=keyword>voices</span>(offset, depth, delayRate);</p> <p class=desc>Alters the parameters in a running flanger (previously started with begin). </p> <h3>Examples</h3> <p class=exam>File > Examples > Audio > Effects > Flange </p> <h3>Notes</h3> <p>The longer the length of the delay buffer, the more memory blocks are used.</p> <p>Try these settings:<br> #define FLANGE_DELAY_LENGTH (2*AUDIO_BLOCK_SAMPLES)<br> and<br> int s_idx = 2*FLANGE_DELAY_LENGTH/4;<br> int s_depth = FLANGE_DELAY_LENGTH/4;<br> double s_freq = 3;</p> <p>The flange effect can also produce a chorus-like effect if a longer delay line is used with a slower modulation rate, for example try:<br> #define FLANGE_DELAY_LENGTH (12*AUDIO_BLOCK_SAMPLES)<br> and<br> int s_idx = 3*FLANGE_DELAY_LENGTH/4;<br> int s_depth = FLANGE_DELAY_LENGTH/8;<br> double s_freq = .0625;</p> </script> <script type="text/x-red" data-template-name="AudioEffectFlange"> <div class="form-row"> <label for="node-input-name"><i class="fa fa-tag"></i> Name</label> <input type="text" id="node-input-name" placeholder="Name"> </div> </script>