Enter your Lemon Squeezy license key to unlock all Pro features: spectrum, waveform, pitch detection, vibrato & session stats.
The Singer's Formant (SF) is a concentration of acoustic energy between 2 and 4 kHz, produced when a trained singer clusters their third, fourth, and fifth vocal formants. It allows the voice to cut through an orchestra without amplification. This analyzer measures the ratio of SF energy (2–10 kHz) to chest energy (100–800 Hz) in real time, giving a precise dB readout of how much resonance the voice carries relative to its fundamental strength.
Click Start Microphone and sing a sustained note. The Harmonics Meter shows SF / Chest in dB — values near 0 dB indicate balanced tone; negative values indicate warm, chest-dominant voice; positive values indicate a bright, forward sound with strong Singer's Formant. The session box plot accumulates readings over time, giving a statistical picture of your typical resonance balance across a full vocal session.
The analyzer uses a Harmonic Product Spectrum algorithm to detect the fundamental frequency of your voice from 80 Hz to 1500 Hz — covering bass through soprano range. Detected pitch is shown as a note name with octave (e.g., A4 = 440 Hz), a live tuner bar for intonation feedback, and a scrolling pitch history graph showing the last ten seconds of intonation. Vibrato rate (Hz) and depth (cents) are measured automatically when the voice sustains a pitch with sufficient oscillation.
The Chest zone (100–800 Hz) covers the fundamental frequency and the first two formants (F1/F2), which determine vowel quality and the basic fullness of the voice. The Singer's Formant zone (2–10 kHz) captures the upper formant cluster (F3–F5) responsible for vocal brilliance and projection. The Floor (dB) setting acts as a noise gate — frequency bins below the threshold are excluded from both band calculations to prevent room noise from skewing the ratio.