Spectrum Analyser - Audio spectrum analyzer

Audio spectrum analyzer designed for your microphone.

Frequency divisions ranging from 64 to 8192 (FFT size between 128 and 16384).

Spectrum range up to 22 kHz (can be reduced to 1 kHz for improved detail).

Various FFT windowing options available: Bartlett, Blackman, Flat Top, Hanning, Hamming, Tukey, Welch, or none.

Features include auto-scaling, pinch to zoom, and drag to pan functionalities.

Offers both linear and logarithmic scales.

Peak frequency detection utilizing polynomial fitting.

Includes averaging, minimum, and maximum values.

Ability to save data in CSV format (requires Write External Storage Permission).

Options for free or snapping to the peak cursor.

Supports octave bands: full, half, third, sixth, ninth, or twelfth bands.

Weighting options include A, C, or None (A weighting adjusts frequencies based on human perception of loudness).

Musical note indicator that shows green if within 5 cents and orange if within 10 cents.

Auto-scaling feature for the microphone input trace.

To ensure optimal performance on slower devices, it's advisable to keep the FFT size smaller.

More comprehensive explanations are available through other resources.

Audio Spectrum Analyzer Pro: Your Pocket-Sized Laboratory for Sound Mastery

This app has fundamentally transformed how I perceive and interact with sound—turning my smartphone into a professional-grade audio analysis toolkit that rivals dedicated hardware costing hundreds more.

From the moment I first visualized my voice through its razor-sharp spectrum display, I was captivated: watching real-time frequency distributions dance across the screen with precision (adjustable from 64 to 8,192 divisions) feels like unlocking a hidden dimension of audio. As a musician, the musical note indicator is revolutionary—seeing notes flash green when perfectly tuned (±5 cents) or orange when close (±10 cents) has sharpened my ear and streamlined instrument calibration.

The ability to zoom and pan intuitively across linear or logarithmic scales while applying A-weighting (mimicking human hearing) or specialized window functions (Hanning for transients, Flat Top for amplitude accuracy) reveals nuances I’d previously only theorized about.

For technical work, features like peak frequency detection (using polynomial fitting to nail exact resonance points) and octave band filtering (third-band analysis for acoustic treatment tuning) deliver lab-level rigor.

Exporting CSV data lets me document measurements professionally, while auto-scaling microphone input ensures clarity even in dynamic environments. 

The flexibility to throttle FFT size for older devices ensures buttery performance—I often cap it at 4,096 for live sound checks. Whether diagnosing room modes at 22 kHz or isolating a humming appliance at 1 kHz, this tool makes the invisible tactile. 

It’s not just for engineers; podcasters can optimize mic placement, and teachers can demonstrate acoustics visually. For anyone who listens critically, this app isn’t just useful—it’s revelatory. A masterpiece of functional design that turns curiosity into expertise.