Your peak meter can miss 3 dB.

Sample peaks aren't the peaks your listener's converter plays. On a test tone, every sample read -3.01 dBFS while the real wave hit 0.00 dBTP.

Same signal, two meters

A full-scale sine at a quarter of the sample rate, sampled 45 degrees off its peaks. Every sample reads -3 dB. The wave between them hits 0.

What to do

• Meter in true peak (dBTP), not sample peak.
• Set your final ceiling at -1 dBTP. That leaves room for AAC and MP3 encoding.
• Peaks between samples are real: the playback filter in every converter rebuilds them.

All 48 Mix Notes   Next: Your loud master gets turned down.