Peak captures the largest magnitude within an interval. RMS = sqrt(mean(x²)) describes the effective level or average energy over a time window. Peak catches brief pick attacks; RMS helps show a note's sustained density. A sine wave with peak A has an RMS of A/√2, about 3.01 dB below its peak when both use the same amplitude reference. Other products can use different RMS meter conventions.
Overall Peak monitors the combined signal. Band RMS shows sustained energy within a frequency range; band Peak shows a brief excursion after the band filter. FFT-bin peaks, filtered-band peaks, and overall waveform peaks are different measurements.
Rigs displays 20-band analysis on a shared −60 to 0 dBFS scale, with an RMS line and segmented Peak bars with peak hold. HIGH is a headroom warning, rather than proof of clipping. Overlapping bands and phase mean you cannot simply add the band readings to obtain Overall Peak. The highest band is not, by itself, proof of what caused an overload or an automatic reason to cut that band with EQ.
An EQ curve shows the change being applied; a spectrum shows what is in the signal. A guitar's spectrum does not need to be flat. Use meters for clues, then listen. When comparing before and after, use the same phrase, clip boundaries, level, and measurement point.
Concept references
Peak versus RMS
Why can a high transient have a low RMS?
- Sample Peak
- -6.02 dBFS
- RMS
- -9.03 dBFS
- Peak − RMS difference
- 3.01 dB
A steady sine has RMS = Peak / √2, or 3.01 dB below Peak. Extending the window by whole periods does not change its RMS.
Peak and RMS use the same digital reference. A single 2 ms pulse: a longer window lowers RMS, while Peak stays the same. This is not a true-peak meter or the native band algorithm.