Sorry, you need to enable JavaScript to visit this website.

4 Band Parametric EQ (fil4.lv2)

Screen dump: 

4 Band Parametric EQ (fil4.lv2) is a graphical EQ with High/Low shelfs and High/Low Pass filters which is based on DSP from Fons Adriaensen's highly regarded fil-plugin. It is available in both mono and stereo variants and has a spectrum display plus waterfall FFT history built-in. The display also has vertical zoom and the window can be resized.

There is also a standalone JACK client of the plugin available. fil4.lv2 is part of x42-plugins by Robin Gareus.