What is the difference between peak program level and true sample peak?

The peak program figure integrates over ten millisecond blocks and behaves like a hardware PPM, so it reflects transient energy rather than a single instantaneous value. The true sample peak is the largest absolute sample in the file, which is why it drives the over warning.

When does the over warning appear?

When the sample peak reaches minus zero point one dBFS or higher. That threshold is fixed rather than adjustable, and it is deliberately just below full scale so that material sitting on the ceiling is flagged rather than only material that has clearly exceeded it.

Why do I need both a PPM and a true peak meter?

Because they answer different questions. A PPM tells you how the programme rides against the ceiling and whether the samples have reached it, while a true peak meter estimates the reconstructed level between samples, which is what a converter or a lossy encoder will react to.

What do the colours on the bar mean?

Green means the reading is safely below minus nine, yellow is between minus nine and minus three, and red is above minus three. The same colouring appears on the envelope bars, where any hundred millisecond window above minus three is drawn red.

Is the programme too hot if it touches the red?

Not necessarily. Red indicates that peaks are close to the ceiling, which matters most for material that will be encoded lossily or converted to analog. Reduce gain or limit the peaks if a delivery specification applies, and confirm with the true peak meter rather than the sample reading alone.

PPM Meter

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VU Meter

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True Peak Meter

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Crest Factor Meter

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RMS Meter

Measure RMS audio levels

PPM Meter reads a file with the fast ballistics of a peak program meter, integrating over ten millisecond blocks and warning when samples reach the ceiling. Where a VU meter averages, this one catches.

What is PPM Meter?

A large peak program figure heads the panel, with the true sample peak beside it and a scale marked at zero, minus three, minus six, minus nine, minus twelve, minus twenty four and minus forty eight dBFS.

What the meter reports:

The peak program level, taken from ten millisecond block peaks, presented in dBFS with a dash if the file is effectively silent.
The true sample peak, which is the largest absolute sample value in the file, used to drive the over warning.
A bar that turns yellow above minus nine and red above minus three, so the approach to the ceiling is visible before it is reached.
A warning line reading over when the sample peak reaches minus zero point one dBFS or higher.
An envelope row with one bar per hundred milliseconds, coloured red for any window above minus three, giving a view of how the level moves across the file.

The two figures measure different things on purpose. The peak program level is a short-block integration, roughly matching how a hardware PPM responds, so it reflects the loudness of transients over ten milliseconds rather than a single instantaneous sample. The over lamp, by contrast, is driven by the actual maximum sample value, because the point of an over indicator is to flag the exact moment a converter ran out of headroom, and an integrated figure would miss that by averaging. Keeping both means the display can warn that a programme is riding too close to the ceiling without falsely declaring an over, and can also catch a single clipped sample that the integrated figure reports comfortably below the limit. The envelope bars make the same distinction over time, highlighting any hundred millisecond window whose peak exceeds minus three decibels. The 10 millisecond block is the integration that separates a peak program meter from an averaging meter: short enough to catch the arrival of a transient and long enough to ignore the shape of any single sample. That makes this the meter to watch when setting levels for material with hard attacks, and it is why the true sample peak sits beside it, because an integrated figure alone will never flag a single clipped sample.

What it does not attempt:

Only the sample peak is checked for overs, so inter-sample overshoot is not reported here.
The over threshold is fixed at minus zero point one dBFS with no adjustable tolerance.
The scale stops at zero, so content above full scale shows as a full bar rather than a value.
One integrated figure covers all channels, with no per-channel breakdown.
There is no held peak marker that persists after the moment has passed.
Nothing is exported and no correction is applied.

Use it as the peak-side companion when preparing material for delivery: it tells you how close the programme sits to the ceiling and whether anything has actually touched it. The VU meter answers the perceptual question with slower ballistics, and the true peak meter extends the over check to the level between samples, which is the measurement a lossy encode or a converter will react to.

How to use PPM Meter

Drop an audio file onto the panel; the peak program measurement starts straight away.
Read the large peak program figure and compare it with the true sample peak beside it.
Watch the bar colour: yellow signals passing minus nine, red signals passing minus three.
Check for the over warning and scan the envelope row for any window marked red.

When to use PPM Meter vs related tools

PPM Meter is the peak-side reading for programme material, catching transients that an averaged meter would smooth away. VU Meter reads the same file with the slower ballistics that match perceived loudness, and True Peak Meter extends the over check from the samples to the reconstructed signal. Where a ceiling has to be enforced rather than measured, Peak Limiter applies it, and Crest Factor Meter explains how far the peaks sit above the average.

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