I guess that you must be using an older version of Audacity. As of version 2.3.3 the Equalization effect has been replaced with “Filter Curve EQ” (https://manual.audacityteam.org/man/filter_curve.html)

In the Audacity 2.3.3 version of Filter Curve, there is no direct support for importing filter curves. The Audacity 2.4.0 version (due to be released this month) is able to import curves, but the format is different from the old Equalization effect.

The new format for filter curves is a simple text file rather than XML. Here’s an example:

```
FilterCurve:f0="95.922748" f1="101.08667" f2="9989.5734" f3="9989.5734" FilterLength="8191" InterpolateLin="0" InterpolationMethod="B-spline" v0="-120" v1="-0.53097343" v2="-0.067111969" v3="-117.65102"
```

Breaking this down:

```
FilterCurve: // The name of the effect
```

```
f0="95.922748" f1="101.08667" f2="9989.5734"... // The frequency values of each point
```

```
FilterLength="8191" InterpolateLin="0" InterpolationMethod="B-spline" // Standard filter parameter. Should not normally be changed
```

```
v0="-120" v1="-0.53097343" v2="-0.067111969"... // The dB values for each point
```

The good part of this is that we can now use a Macro command to apply the filter and pass the curve parameters in the command.

Unfortunately we are not able to obtain the spectrum data from macro commands, but it would be possible to do the analysis in Nyquist. FFT analysis in Nyquist isn’t easy, but it is possible.

The disadvantage of using a large “Size” in the spectrum plot is that it can produce too much detail in the high frequencies. For musical purposes we only want the general shape of the EQ, not individual notes. FFT analysis provides equally spaced frequency bins across the entire audio spectrum, so we end up with just a few bins per octave at low frequencies, and possibly hundreds of bins per octave at high frequencies. It would be better if we used a fairly high FFT size so that we can get a reasonable number of bins per octave at low frequencies, but filter the data at high frequencies (smooth the curve) so that we have the same number of data points per octave across the entire frequency spectrum (say 3 bands per octave).

The way that I’d see a future version of Eq Match, is for it to be a Macro. The Macro would first run a Nyquist plug-in on the first track to analyze the spectrum and process it to produce a 3 band per octave output. The second command applies the same Nyquist plug-in to analyze the second (target) track. The third command runs a Nyquist Macro that reads the two data files, generates the “corrective” settings for the Filter Curve (or Graphic EQ effect), and applies the filter to the target track.

This will of course only be possible after Audacity 2.4.0 is released.