Frequency Range Analyzer
Measure the full frequency range of any sound source. Track minimum and maximum Hz over your session, see how your audio maps against instrument ranges (piano, guitar, voice, violin), view energy breakdown across sub-bass through treble bands, and compare two recordings side by side — all processed locally in your browser.
Frequency Range Analyzer Tool
| Time | Min Hz | Max Hz | Bandwidth | Note Range |
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How to Use the Frequency Range Analyzer
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Start Listening
Click "Start Listening" and grant microphone permission. Select your preferred microphone from the dropdown if needed. The waterfall spectrogram and range tracking begin immediately.
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Play Your Sound
Play the instrument, vocal, or sound source you want to analyze. The tool continuously tracks the minimum and maximum frequencies detected above the sensitivity threshold, updating the range in real time.
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Review the Range
Check the instrument overlay to see how your sound maps against piano, guitar, voice, violin, and bass ranges. The energy breakdown shows how power is distributed across sub-bass, bass, mid, and treble bands as percentages.
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Compare A vs B
Use "Record A" and "Record B" to capture two 3-second samples for side-by-side comparison. Great for comparing microphone positions, EQ settings, or different instruments.
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Export Your Data
Use "Export CSV" to download the full session history or "Copy Summary" for a quick text report of the detected frequency range.
Understanding Your Results
Min/Max Frequency Tracking
The tool continuously monitors the audio spectrum and records the lowest and highest frequencies that exceed the sensitivity threshold during your session. This gives you the full frequency range of your sound source. The bandwidth is simply the difference between max and min Hz.
Instrument Range Overlay
Five reference instruments are displayed as horizontal bars showing their standard playing range. Your detected range is overlaid on each bar, making it easy to see which instruments your sound overlaps with. For example, a baritone voice might span from E2 (82 Hz) to A4 (440 Hz), covering the guitar range but only a small portion of the piano range.
Energy Breakdown
The energy distribution shows what percentage of total power falls within each frequency band: sub-bass (20–60 Hz), bass (60–250 Hz), low-mid (250–500 Hz), mid (500–2k Hz), upper-mid (2k–6k Hz), and treble (6k–20k Hz). This helps identify tonal balance and frequency emphasis.
Waterfall Spectrogram
The waterfall display scrolls downward over time, with frequency on the horizontal axis and color representing intensity. This reveals how the frequency content changes over time, making it useful for identifying transients, vibrato, and frequency sweeps.
A vs B Comparison
Recording two 3-second samples lets you compare frequency ranges side by side. This is useful for comparing different mic positions, before/after EQ changes, or two different sound sources.
Technical Background
The Frequency Range Analyzer uses the Web Audio API to perform real-time Fast Fourier Transform (FFT) analysis on microphone input. The tool processes audio entirely in the browser with zero server communication.
FFT Analysis
Audio is sampled at the browser's native sample rate (typically 44,100 or 48,000 Hz) and analyzed using an 8,192-point FFT, yielding a frequency resolution of approximately 5.4 Hz per bin. The analyser node provides magnitude data in decibels, which the tool converts to linear power for energy integration.
Frequency Detection
Min and max frequencies are determined by scanning FFT bins from low to high. Only bins whose magnitude exceeds the user-configured sensitivity threshold are considered, filtering out noise floor contributions. The detected range expands over the session — the minimum only decreases and the maximum only increases.
Energy Integration
Band energy is computed by summing the linear power (10^(dB/10)) of all FFT bins within each frequency band, then dividing by the total power across all bands to produce a percentage. This gives a perceptually meaningful picture of where the sound's energy is concentrated.
Frequently Asked Questions
What does the Frequency Range Analyzer measure?
It measures the minimum and maximum frequencies present in your audio signal above a configurable sensitivity threshold. It also calculates bandwidth (max minus min), maps the range to musical notes, overlays instrument reference ranges, and breaks down energy by frequency band.
How accurate is the frequency range measurement?
With an 8,192-point FFT at a 44.1 kHz sample rate, the frequency resolution is approximately 5.4 Hz per bin. This is accurate enough for most musical and audio analysis purposes. Accuracy depends on your microphone quality and ambient noise levels.
What are the instrument range references based on?
The instrument ranges represent standard fundamental frequency ranges: Piano covers A0 (27.5 Hz) to C8 (4186 Hz), Guitar E2 (82 Hz) to D6 (1175 Hz), Voice spans roughly F2 (85 Hz) to C6 (1100 Hz), Violin G3 (196 Hz) to E7 (3136 Hz), and Bass Guitar E1 (41 Hz) to G4 (392 Hz).
How does the A vs B comparison work?
Click "Record A" to capture a 3-second sample, then "Record B" for a second sample. The tool analyzes each recording's frequency range, bandwidth, note range, and dominant frequency independently, displaying them side by side for easy comparison.
What does the energy breakdown percentage mean?
Each percentage represents the proportion of total signal power within that frequency band. For example, if bass shows 45%, it means 45% of the total energy in your signal falls between 60 Hz and 250 Hz. The six bands always sum to 100%.
Is my audio data private?
Absolutely. All frequency analysis runs 100% in your browser using the Web Audio API. No audio data is ever recorded, transmitted, or stored on any server. The tool works completely offline once loaded.
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