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Compression Frequency Analyzer

See the live level and dynamic range (loudest minus quietest) of each octave band from your microphone — revealing which frequencies are the most and least dynamic, the bands a multiband compressor would work hardest on.

Relative dBFS, single-source view — not a before/after file comparison. This shows per-band level and how much each band’s level varies over time. It can’t compare a compressed vs uncompressed version (that needs offline file processing), and the numbers depend on your uncalibrated mic and room. Use it to see where the dynamics live. Nothing is recorded or uploaded.

Idle — press Start.
Current level Dynamic range (loudest−quietest)

What This Shows

The microphone signal is split into octave bands (63 Hz up to 16 kHz). For each band the analyzer shows the current level and, since you pressed Start, its dynamic range — the difference in dB between that band’s loudest and quietest moments (above a noise gate). A band with a large range is highly dynamic; a band with a small range is steady or already compressed. That’s exactly the information you’d use to decide where multiband compression might help.

Because it reads a live, uncalibrated, single microphone signal, the figures are relative dBFS and include your room. It’s a way to see per-band dynamics, not a calibrated measurement or a true before/after comparison of a compressed file.

Frequently Asked Questions

What does a band’s dynamic range tell me?
How much that frequency band’s level varied between its loudest and quietest moments. Large range = very dynamic (a candidate for compression); small range = steady or already compressed.
Can it compare before and after compression?
Not directly — that needs processing an audio file through a compressor and comparing. This is a live, single-source view. You could, however, run a source through a compressor and watch how the per-band ranges shrink.
Why are these octave bands?
Octave bands (each centre double the last) match how we hear and how multiband processors are usually split. Each band here spans from its centre ÷ √2 to its centre × √2.
Are the levels calibrated?
No. They’re relative dBFS from an uncalibrated mic and include the room, so compare bands against each other rather than treating the numbers as absolute.
Is my audio recorded?
No. The signal is analyzed in real time and is never recorded, saved, or transmitted. The microphone is released when you press Stop or close the tab.