🔍

Compression Frequency Analyzer

This compression frequency analyzer shows the live per-band 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 and a practical guide to setting per-band dynamics before you open your DAW.

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)

Share or embed this tool

Free to use on your own website — WordPress, Wix, or any platform. Paste one line and it works instantly, resizing to fit.


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). The noise gate ignores samples below a low-level threshold so that room noise doesn’t artificially widen the range reading when the source is silent. 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. To check the overall spectral balance of a signal, pair this tool with the audio spectrum analyzer, which shows a full FFT view with peak hold.

In practice, vocal recordings tend to be most dynamic in the 125–500 Hz "body" region and can spike in the 2–4 kHz presence band when consonants hit. Drum overheads often show very high ranges across most bands. Seeing these patterns in real time tells you which bands of a multiband compressor or dynamic equalizer deserve the most attention — before you commit settings in your DAW.

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.
Which octave bands are most dynamic for vocals?
Vocals typically show the highest per-band dynamic range in the 125–500 Hz body region (where chest resonance and proximity effect cause level swings) and in the 2–4 kHz presence band (where consonants and sibilance spike). If those bands show significantly higher dynamic range than the rest, targeted multiband compression or a de-esser around 4–8 kHz is usually the right corrective action.
How does this differ from a full-band dynamic range meter?
A standard dynamic range meter shows the loudness swing of the whole mix as a single number. This analyzer splits the signal into octave bands first, so you see where in the spectrum the dynamics are concentrated. A signal can have a modest full-band range yet still have one narrow band that is wildly variable — exactly the situation that calls for multiband rather than broadband compression.
Can I use this to set multiband compressor thresholds?
It gives you a useful starting reference, not a precise threshold readout. Watch the per-band level bars while the source plays at its loudest and quietest moments — the current-level bar shows roughly where each band peaks. Because the reading is relative dBFS from an uncalibrated mic, treat those numbers as comparative guidance for deciding which bands need the most compression, then dial in the actual thresholds by ear and by metering inside your DAW or plugin.