Match EQ

The Match EQ allows you to store the average frequency spectrum of an audio file as a template and apply the template to another audio signal so that it matches the spectrum of the original file. This is also known as a fingerprint EQ, where one sonic fingerprint is applied to another signal.

The Match EQ enables you to acoustically match the tonal quality or overall sound of different songs you plan to include on an album, for example, or to impart the color of any source recording to your own projects.

Match EQ is a learning equalizer that analyzes the frequency spectrum of an audio signal such as an audio file, a channel strip input signal, or a template. The average frequency spectrum of the source file (the template) and of the current material (this can be the entire project or individual channel strips within it) is analyzed. These two spectra are then matched, creating a filter curve. This filter curve adapts the frequency response of the current material to match that of the template. Before applying the filter curve, you can modify it by boosting or cutting any number of frequencies, or by inverting the curve.

The Analyzer allows you to visually compare the frequency spectrum of the source file and the resulting curve, making it easier to make manual corrections at specific points within the spectrum.

You can use the Match EQ in different ways, depending on your intended outcome and the audio you’re working with. In general, you will want to make your mix sound similar to an existing recording—either your own or that of another artist.

Note: Although the Match EQ acoustically matches the frequency curve of two audio signals, it does not match any dynamic differences between the two signals.

Match EQ Parameters

The Match EQ offers the following parameters.

Figure. Match EQ window.
Match EQ Analyzer Parameters
  • Analyzer button: Turns the Analyzer function on or off.
  • Pre/Post menu: Determines whether the Analyzer looks at the signal before (Pre) or after (Post) the filter curve is applied.
  • View button: Determines if separate curves are displayed by the Analyzer (L&R for stereo, All Cha for surround) or the summed maximum level is shown (LR Max for stereo, Cha Max for surround).

    Note: The View parameters are disabled when using the effect on a mono channel.

  • Select buttons: Determine if changes made to the filter curve (created by matching the template with the current material) are applied to the left channel (L), the right channel (R), or both channels (L+R).

    Note: The Select parameters are disabled when using the effect on a mono channel.

  • Channel Link slider and field: Refines the settings made with the Select buttons or Select pop-up menu.
    • When set to 100%, all channels (L and R for stereo, or all surround channels) are represented by a common EQ curve.

    • When set to 0%, a separate filter curve is displayed for each channel. Use the Select buttons or Select pop-up menu to choose each channel.

    • Settings between 0 and 100% allow you to blend these values with your filter curve changes for each channel. This results in a hybrid curve.

    Note: The Channel Link parameters are disabled when using the effect on a mono channel.

Match EQ Display, Learn, and Match Parameters
  • Graphical display: Displays the filter curve created by matching the template to the current material. You can edit the filter curve (see Editing the Match EQ Filter Curve).
  • Template Learn button: Click to start the process of learning the frequency spectrum of the source file. Click again to stop the learning process.
  • Current Material Learn button: Click to start the process of learning the frequency spectrum of the project you want to match the source file. Click again to stop the learning process.
  • Current Material Match button: Matches the frequency spectrum of the current material to that of the template (source) file.
Match EQ Processing Parameters
  • Phase button: Determines whether processing alters (Minimal) or does not alter the signal phase (Linear). The Minimal setting results in lower latency.
  • Apply slider and field: Determines the impact of the filter curve on the signal.
    • Values above 100% magnify the effect.

    • Values below 100% reduce it.

    • Negative values (-1% to -100%) invert the peaks and troughs in the filter curve.

    • A value of 100% has no impact on the filter curve.

  • Smoothing slider and field: Sets the amount of smoothing for the filter curve, using a constant bandwidth set in semitone steps. A value of 0.0 has no impact on the filter curve. A value of 1.0 means a smoothing bandwidth of one semitone. A value of 4.0 means a smoothing bandwidth of four semitones (a major third). A value of 12.0 means a smoothing bandwidth of one octave, and so on.

    Note: Smoothing has no effect on any manual changes you make to the filter curve.

Using the Match EQ

Following is a common usage example that you can adapt to your own workflow. In this example, the frequency spectrum of a mix is matched with the spectrum of a source audio file.

To learn or create a Match EQ template
  1. Choose Process > Effects > EQ > Match EQ.

    The Match EQ HUD appears.

  2. Adjust the Match EQ settings to your liking, or drag source audio onto the Template Learn button.

  3. If the presets drawer is hidden, click the Show Presets button.

  4. Click the Add (+) button to create a new preset.

  5. Type the name of the new preset.

  6. Press Return.

    The preset is saved with the name you typed.

To match the EQ of a project mix to the EQ of a source audio file
  1. In the project you want to match to the source audio file, apply a Match EQ (typically on Output 1-2).

  2. Drag the source audio file onto the Template Learn button.

  3. Return to the start of your mix, click Current Material Learn, then play your mix (the current material) from start to finish.

  4. When you are done, click Current Material Match (this automatically disengages the Current Material Learn button).

You can drag an audio file onto the Template Learn or Current Material Learn button for use as either the template or the current material. A progress bar appears while the Match EQ is analyzing the file. You can also load a previously saved plug-in setting, or you can import the settings of another unsaved Match EQ instance by copying and pasting.

When you click either of the Learn buttons, the View parameter is set to Automatic and the graphical display shows the frequency curve for the function. You can review any of the frequency curves when no file is being processed by choosing one of the other View options.

The filter curve is updated automatically each time a new template or current material spectrum is learned or loaded when the Match button is enabled. You can alternate between the matched (and possibly scaled and/or manually modified) filter curve and a flat response by activating/deactivating the Match button.

Only one of the Learn buttons can be active at a time. For example, if the Learn button in the Template section is active and you click the Learn button in the Current Material section, the analysis of the template file stops, the current status is used as the spectral template, and analysis of the incoming audio signal (Current Material) begins.

Note: Each time you match two audio signals, either by loading/learning a new spectrum while Match is activated or by activating Match after a new spectrum has been loaded, any existing changes to the filter curve are discarded, and Apply is set to 100%.

By default, the Apply slider is set to 100% when you learn the frequency curve of an audio signal. In many cases you may want to lower it slightly to avoid extreme spectral changes to your mix. It is also recommended that you use the Smoothing slider to adjust the spectral detail of the generated EQ curve.

Using the Match EQ Shortcut Menu

Control-click (or right-click) either Learn button to open a shortcut menu. This offers commands that can be applied to the spectrum of the template or the current material.

  • Clear Current Material Spectrum: Clears the current spectrum.
  • Copy Current Spectrum: Copies the current spectrum to the Clipboard (this can be used by any Match EQ instance in the current project).
  • Paste Current Spectrum: Pastes the Clipboard contents to the current Match EQ instance.
  • Load Current Material Spectrum from setting file: Loads the spectrum from a stored setting file.
  • Generate Current Material Spectrum from audio file: Generates a frequency spectrum for an audio file that you have chosen.

Editing the Match EQ Filter Curve

You can graphically edit the filter curve in the graphical display by adjusting the various points shown in each band. As you drag, the current values appear in a small box inside the graphical display, allowing you to make precise adjustments.

To adjust Match EQ curve values
  • Drag horizontally to shift the peak frequency for the band (over the entire spectrum).

  • Drag vertically to adjust the gain of the band.

  • Shift-drag vertically to adjust the Q Factor.

  • Option-drag to reset the gain to 0 dB.

Note: If you manually modify the filter curve, you can restore it to the original (or flat) curve by Option-clicking the background of the Analyzer display. Option-click the background again to restore the most recent curve.

The Q factor of the filter is determined (and set) by the vertical distance between the clicked position and the curve.

To set the Match EQ Q factor
  • Click the curve directly to set the maximum Q value of 10 (for notch-like filters).

  • Click above or below the curve to decrease the Q value. The farther you click from the curve, the smaller the value (down to the minimum of 0.3).

The colors and modes of the dB scales on the left and right of the display are automatically adapted to the active function. If the Analyzer is active, the left scale displays the average spectrum in the signal, while the right scale serves as a reference for the peak values of the Analyzer. A dynamic range of 60 dB is shown by default. If this is not precise enough for your edits, you can increase the range.

To change the Match EQ scale range
  • Drag either scale to set values of up to +20 dB and -100 dB.

To change Match EQ gain with the scales
  • Drag either scale to adjust the overall gain of the filter curve from -30 to +30 dB.

The left scale—and the right, if the Analyzer is inactive—shows the dB values for the filter curve in an appropriate color.