Frequency Detector Tool vs Spectrum

Frequency Detector Tool is a free, elegant frequency and musical-key analyzer for producers, mixing engineers, sound healers, and the musically curious. Type in any frequency in Hertz — like 315, 2.5k, or 29834 — and instantly see: The musical note it maps to (e.g. A4 = 440 Hz) How many cents sharp or flat it is Whether it's IN KEY for the key you've selected The nearest "cut candidate" — the closest out-of-key frequency Vocal context notes to guide your EQ decisions Pick your key from all 12 tones and the whole analysis updates instantly, showing the in-key snap, the nearest cut, and vocal-range context (like the "Mud Zone" around 250–400 Hz). Open the full frequency chart to see every note across octaves 0–7, laid out for boosting and cutting in your chosen key — scroll to explore the entire spectrum. Also included: Clickable Solfeggio frequencies (432, 528, 639, 741, 852, 963) with a note on what each is associated with "Did You Know?" music-theory facts A calm, sacred-geometry inspired interface Frequency Detector Tool is completely free — no ads, no subscriptions, no catch. It's my first app, made with love. If it helps you, an optional donation on eyeheru369.com supports more free tools. Works on iPhone, iPad, and Apple Vision Pro.

Spectrum turns your phone into a modern real-time audio analyzer - the clean, fast tool that older spectrum apps never gave you. See sound the moment it happens: a live FFT frequency spectrum and a scrolling spectrogram (waterfall), with automatic peak detection and the matching musical note. Built for a phone screen, with a beautiful dark and light theme - not a cramped desktop port. WHY SPECTRUM • Modern, readable interface - designed for touch, dark & light themes • Save your measurements and revisit them anytime (most analyzers forget everything the moment you close them) • Export the spectrogram as a high-resolution image, or your data as CSV • Works on both iPhone and iPad • Real peak frequency + musical note readout, in cents FEATURES • Real-time FFT spectrum, log or linear frequency axis • Spectrogram (waterfall) view • Tap the chart for a frequency cursor with dB and musical note • Peak hold and peak-frequency tracking • Musical note detection (A4 = 440 Hz) • A-weighting for perceived loudness • Adjustable FFT size (2048 / 4096 / 8192) • Save, name and organize measurements • Image & CSV export • 8 languages SPECTRUM PRO - one-time purchase, no subscription • 1/3 octave RTA view with per-band peak hold - the classic real-time analyzer used for live sound and room tuning • Tone generator: sine tones, 20 Hz-20 kHz logarithmic sweep, white & pink noise for testing speakers and room acoustics • Peak list: the strongest peaks with harmonics tagged • Up to 4 frequency markers on the chart • Calibration offset (±20 dB) to match a reference meter • Extra-high resolution 16384 FFT • High-resolution image export and no ads, forever Everything is processed on your device - no audio is ever uploaded. Microphone access is the only permission needed. Perfect for musicians, audio engineers, students, DIY speaker builders, hum & noise hunters, and anyone curious about the sounds around them.