Guides

Why your master distorts after upload: true peak and encoder overshoot

Updated 2026-09-06

You checked the file. The meter never touched zero. You uploaded it, and now the chorus crackles on Spotify. Nothing is wrong with Spotify. Something is wrong with the meter.

Sample peak is not the peak

A digital file is a list of samples. The real waveform passes between them, and between two samples that both sit at -0.2 dB the true waveform can pass through +0.5 dB. A normal peak meter reads the samples and reports -0.2. A true peak meter oversamples the signal, reconstructs the waveform, and reports the +0.5. That overshoot is where the clipping happens.

Why upload makes it worse

Every streaming service converts your WAV to a lossy format. The encoder reshapes the waveform slightly, and reshaped waveforms overshoot more, typically by another half to one decibel. A master that measured -0.1 dBTP can come out of the encoder at +0.8 and clip on playback.

The fix

• Master with a true-peak limiter, not a sample-peak one.
• Set the ceiling at -1.0 dBTP. Every major service recommends it, and it costs you nothing audible in loudness.
• Verify with an oversampled meter after the limiter, on the final file. A limiter's own readout is a promise; the meter is a measurement.

Burnish holds every master at or under -1 dBTP with a limiter that measures at four times oversampling, then measures the finished file again and prints the number on the report. If the file cannot be made to pass, the master is not released. It has never happened, and the check exists so it never will.