The final safety net — always-on 4x FIR oversampled inter-sample peak detection positioned after all shaping stages. Working alongside the upstream TruePeak Limiter as a complementary protection circuit, it guarantees zero inter-sample overshoots at negligible CPU cost.
Digital audio samples represent discrete points. Between these points, the reconstructed analog waveform can exceed 0 dBFS by several dB. These inter-sample peaks are invisible to standard sample-peak meters but cause real distortion in D/A converters and lossy encoders. TruePeak Guard catches them all with a 48-tap Kaiser-windowed sinc filter running at 4x oversampling — always on, at negligible CPU cost.
A standard limiter sees sample values. But when a D/A converter reconstructs the analog waveform using sinc interpolation, the curve between samples can exceed the digital ceiling. This is especially problematic after lossy encoding (AAC, MP3) which adds its own inter-sample peaks. TruePeak Guard uses the same mathematics as the converter itself to predict and prevent these overages.
TruePeak Guard and the upstream TruePeak Limiter work as complementary protection circuits. The Limiter provides precision inter-sample detection before shaping — its lookahead and program-dependent release shape gain reduction smoothly and musically. The Guard catches anything new that the clipper or emphasis introduced after the limiter. The Limiter is precision surgery; the Guard is the safety net. Together, they guarantee broadcast-compliant output with minimal audible artifacts.
The peak protection that catches what others miss — your final guarantee of clean delivery.
