True Peak is a measure that estimates not only the value of each stored digital sample but also the peaks that can occur between samples once D/A conversion restores the continuous waveform. It is expressed in dBTP and is used to check clipping headroom for playback, sample rate conversion, and conversion to compressed formats.
Difference from Sample Peak
Sample Peak is the maximum value of the samples recorded in the file. The actual reconstructed waveform can rise higher between sample points, so True Peak can exceed 0 dBFS even when Sample Peak is below it. This is also known as an inter-sample peak.
How it is measured
A True Peak meter interpolates the waveform between samples, estimating it more finely than the original sample rate to find the maximum. Because the measurement method differs from an ordinary peak meter, switch your DAW’s meter to True Peak mode or use a plugin that supports it.
Why it rises after conversion
Lossy compression such as MP3 and AAC, sample rate conversion, and filtering all change the waveform, and peaks can end up higher than before conversion. Rather than looking only at sample peak before export, it is safer to leave headroom with your distribution format in mind.
Limiters and output ceilings
True Peak limiters let you set the output ceiling in dBTP to hold peaks down. The ceiling you need depends on the destination’s specification for streaming, broadcast, and so on. Lowering the number does not make the audio sound better on its own, so avoid over-limiting.
Check it together with LUFS
LUFS manages overall perceived loudness, True Peak the instantaneous maximum level. Neither on its own tells you the state of your delivery. The loudness adjustment tool lets you work while viewing LUFS-I and estimated True Peak side by side.
