2.1. TrueGain

The TrueGain tab contains configuration and visualization for equal-loudness based gain compensation. This section details each of the individual parameters and components.

TrueGain also supports mini mode for a compact control-focused layout.

Calibration gives TrueGain a reference for estimating the sound pressure level at your listening position. Place TrueGain before room/headphone correction or crossfeed in your monitoring chain, and keep those processors enabled during calibration.

Calibration for Speaker Monitoring:

1. Place an SPL meter at your listening position, using C-weighting and a slow response.
2. Click “Calibrate SPL …”, then select Speakers: Pink Noise (Band-Limited) from calibration signal type. A 1 kHz sine wave and full-bandwidth pink noise are also available.
3. Play one speaker at a time using your monitor controls. At your chosen monitoring volume, set reference SPL to the meter reading. If you are using a reference-level preset, adjust each speaker’s playback level to match it.
4. Click “Stop calibration” and restore normal speaker routing. Keep your monitor volume and downstream processing at their calibrated settings.

For Bob Katz’s K-System, the K-20 reference is 83 dBC SPL per speaker, measured one speaker at a time with pink noise at -20 dBFS RMS (+3). The reference-level drop-down offers common examples; choose the level appropriate to your monitoring setup.

Calibration Signal Levels:

The built-in speaker signals are normalized to -20 dBFS on a sine-referenced RMS (+3) meter, equivalent to approximately -23.01 dBFS mathematical RMS. This RMS reference does not define a fixed LUFS value for program material.

The built-in band-limited pink noise covers 500-2500 Hz. Its stored mono K-weighted calibration measurement is approximately -22.22 LUFS. The EBU reference listening signal covers 500-2000 Hz and is normalized to -23 LUFS. Their bandwidths and normalization targets differ. Adaptive SPL uses the stored measurement for the selected calibration signal and loudness type.

Calibration for Headphone Monitoring:

1. Keep your headphone volume at your chosen listening setting, with headphone correction and crossfeed enabled if you normally use them.
2. Click “Calibrate SPL …”, then select Headphones: Dialog (Male) or Headphones: Dialog (Female) from calibration signal type.
3. Adjust calibration offset until the spoken dialog sounds like a normal conversation from about 3 feet away in a quiet room, then click “Stop calibration”.

While headphone calibration plays, reference SPL updates automatically using Reference SPL = 65 - Calibration offset, in dB SPL. The 65 dB anchor is the plugin’s conversational reference. Dialogue matching provides a subjective estimate of listening level, not a direct measurement of headphone SPL.

Keep the selected calibration signal type after stopping playback so adaptive SPL uses the same baseline. Calibration anchors the contour model to your playback setup; its loudness compensation remains an estimate. Repeat calibration after changing monitor volume or downstream processing.