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Pole-Zero placement
Here’s a Java applet that illustrates pole-zero placement. It lets you design a filter with two poles and two zeros, while showing the resulting frequency response and filter coefficients. It’s also...
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Biquads
One of the most-used filter forms is the biquad. A biquad is a second order (two poles and two zeros) IIR filter. It is high enough order to be useful on its own, and—because of coefficient...
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Type: lowpass highpass bandpass notch peak low shelf high shelf Plot: linear log Sample rate (Hz) Fc (Hz) Q Gain (dB) Something useful: a biquad filter coefficient calculator. Set the filter Type, the...
View ArticleBiquad formulas
For fixed filters, we can plug biquad coefficients into our programs. But often, we need to calculate them on the fly, to user settings or changes in sample rate. As a companion to the biquad...
View ArticleBiquad C++ source code
I don’t want to get into the business of teaching people how to code—there are a huge number of free resources available on the internet to that do that. But I’ll give a small taste for those trying to...
View ArticleBiquad calculator v2
table#EQcontrols { background: transparent; border: 0; border-collapse: separate; border-spacing: 0; } table#EQcontrols td { border: none; white-space: nowrap; } Type: lowpass highpass bandpass notch...
View ArticlePole-Zero placement v2
Pair Pole mag Pole angle Pair Zero mag Zero angle Sample rate (Hz) linear log Plot A new pole-zero calculator An update of the old Java-based pole-zero placement applet—visit that page for tips on...
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