Addition to Filter Curve EQ

Hi there,

I’m very pleased with Audacity ver 3.0.2 - congratulations to all involved.
Here’s a suggestion to allow more precise setting of the frequency on Filter Curve EQ.
It allows fine adjustment of the X axis (frequency) in a similar way to the existing Y axis (level).

Here’s how it might look :

You know you’re not limited to the default horizontal size of the display, right? You can grab one edge of the window and pull. Then you can push the whole thing off the screen and do it again. You can get super accuracy that way without programming or development.

There is one problem with super accuracy. The sound system may not follow you.

This is a pulled and expanded display of the audiobook low rolloff filter.

Screen Shot 2021-05-05 at 3.05.37 AM.png
See that lumpy green line. That’s what the filter is really doing. It’s not following the surgically correct black curve.


Hi Koz,

Yes, I’m aware of how the filter and green line work. Lets say I need a filter centered on 800Hz with a passband of 40Hz at -6dB, and 60Hz at -60dB.
If I could zoom in to a display with X axis from say 750Hz to 850Hz, this would make setting it up much easier.
Also I could see from the green line how close the filter was to the design requirements.

Would anyone else find this useful ?

It sounds like you want a Notch Filter:
You can limit the depth (maximum attenuation) of a notch by mixing in a (much attenuated) copy of the unfiltered audio.

Very rarely, yes. In 99.9% of cases I find that I can see enough simply by maximising the effect window.

For many cases where I might need a better view with the Filter Curve effect, there’s a better alternative available (such as using a notch filter, or one of the “Spectral effect” filters:

It is also possible to define custom filters with Nyquist