RTA SPL - Audio Analyzer Pro

Assessing a sound level or diagnosing a spectral imbalance normally requires a separate sound meter and spectrum analyzer, often expensive or imprecise on mobile — this audio analyzer combines both functions in a native Rust computing engine, with no garbage-collection latency.

🔒 100% Ad-Free • Pro Precision • Zero Data Collection

Enjoy a clean, distraction-free professional tool. The app contains no ads, requires no login, and collects no personal data.

Who is it for, and in what situations?

For a live sound engineer, the audio analyzer lets you fine-tune an equalizer by comparing the measured curve to a target curve (Harman, JBL House) and pinpoint the exact frequency of feedback using the high-resolution mode. For a car audio technician, the app offers dedicated calibration curves (Audiofrog, B&K Optimum, Step-Down) to tune the frequency response of a vehicle cabin. For a health and safety officer, the SLOW/FAST history with NIOSH/OSHA thresholds helps document prolonged noise exposure.

What you gain

Spot a tonal imbalance at a glance thanks to the colored spectral tilt line

Assess listening fatigue in a mix thanks to psychoacoustic sharpness (ACUM, Zwicker model)

Calibrate an audio system with precision thanks to target curves and their ±3.5 dB tolerance corridor

Track noise exposure over time thanks to L10/L50/L90 statistics and LRA

Catch clipping instantly thanks to real-time saturation detection

Key Features

📊 RTA spectral analysis

IIR constant-Q filter bank, resolution from 3 to 24 bands per octave

Live spectral centroid and bandwidth display

Sharpness (ACUM) overlay on high frequencies

🎚️ Professional SPL measurement

A-weighting compliant with IEC 61672, FAST (125 ms) and SLOW (1 s) integration

VU meter with color-coded safety zones and clipping badge

Time history, histogram, and L10/L50/L90 percentiles

🎯 Calibration and target curves

Reference curves: Harman, Audiofrog, JBL House, B&K Optimum, Half Whitledge

Two dynamic range modes: Studio (30–100 dB) and Live (50–120 dB)

Manual microphone calibration (RTA offset, SPL offset)

📘 Built-in learning

Explanatory tooltip on every parameter (theory, typical values, use cases)

A differentiating technical approach

Unlike tools that rely on a fixed-resolution FFT, this audio analyzer uses a constant-Q filter bank (CQT), which better matches human frequency perception. The constant-Q transform delivers better resolution in low frequencies than a classic FFT, whose resolution stays fixed regardless of where in the spectrum you're analyzing — a decisive advantage for precisely identifying a room mode or an EQ issue in the bass range. The signal processing engine, written entirely in Rust, avoids the garbage-collector latency found in competing apps built in Java or Dart.

Transparent pricing & privacy

The app accesses the microphone solely for real-time acoustic analysis. No audio is recorded or transmitted.

100% Ad-Free: No banners, no pop-ups, no interruptions.

Free core features: Essential functions remain available (3/6-band RTA, complete SPL measurement).

Pro Features: Unlock high-resolution 24-band RTA, pro target curves, and Live mode via a simple one-time lifetime purchase — no subscription, no recurring fees.

Install this audio analyzer to measure, calibrate, and understand the sound behavior of your environment starting with your next session.