# DecibelRTA — SPL Meter & Spectrum Analyzer

> SPL Meter & Spectrum Analyzer (iPhone/iPad app by Olivier ADAM.)

- Source: https://appshunter.io/ios/app/decibelrta/id6813196740 (this page in markdown: same URL + `.md`)
- Developer: [Olivier ADAM](https://appshunter.io/developer/6804323644)
- Category: Music, Utilities
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 15.6 · 6 MB
- Languages: American English
- Released: 2026-09-21
- Data updated: 2026-10-09

## What is DecibelRTA?

DecibelRTA is an ultra-fast, professional real-time acoustic analyzer combining a fractional-octave IIR spectrum analyzer and an advanced IEC sound level meter on a unified display.

Engineered with a native, zero-latency DSP core, DecibelRTA displays 11 vital acoustic metrics simultaneously without requiring navigation through menus:

11 METRICS AT A SINGLE GLANCE
• Instant Spectral Pitch: Dominant musical note (e.g. A#2), frequency (Hz), and exact level (dB).
• Core Metrology Chips: Leq 5s (equivalent continuous level), ACUM (psychoacoustic sharpness), LRA (Loudness Range dynamic spread), L50 (median ambient level), and CRST (crest factor).
• Standard SPL Bar: SLOW (1s), FAST (125ms), and instant PEAK decay monitoring.

HIGH-PRECISION SPECTRUM ANALYZER (RTA)
• 3, 6, 12, and 24 bands per octave constant-Q filter bank (up to 240 selective IIR bands).
• Contextual dual-path engine delivering sharp low-frequency transient tracking below 280 Hz.
• Real-time spectral centroid, active -3 dB bandwidth marker, and continuous peak-hold curve.
• Linear regression spectral tilt line (beta) for instantaneous noise color identification (pink, white, brown noise).
• Built-in industry reference target curves (Flat, Audiofrog, Harman Room, JBL House, B&K Optimum) with a ±3 dB tolerance corridor.

IEC 61672 SOUND LEVEL METER & STATISTICS
• Type-standard A-weighting with true-RMS exponential ballistics (FAST / SLOW).
• Continuous 5-second sliding Leq and sliding statistical histogram (L10, L50, L90).
• Dual-mode dynamic range: Studio Mode (30 to 100 dB) and LIVE Mode (50 to 120 dB).
• Fast overload CLIP warning and color-coded acoustic safety levels.

BUILT FOR SOUND PROFESSIONALS
• Live sound engineers & FOH: Quick feedback detection and stage SPL limits.
• Studio & Mastering: Mix tonal balance, dynamic compression (LRA), and high-frequency fatigue check (ACUM).
• Car Audio & Hi-Fi: In-cabin acoustic calibration and speaker alignment against target curves.
• Acoustic & Industrial Hygiene: Noise floor surveys (L90) and OSHA/NIOSH threshold tracking.

Microphone access is strictly processed on-device in real-time. No audio data is ever recorded, stored, or transmitted.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| DecibelRTA PRO | $19.99 | one-time |


## Is DecibelRTA safe?

Not enough ratings yet to assess DecibelRTA.

## Is DecibelRTA legit?

DecibelRTA appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for DecibelRTA is 65 out of 100 points across 7 verification signals from App Store and developer data.


## Version history (last 1 release)

### 1.0 — 2026-09-25

No release notes.

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## More apps by Olivier ADAM

- [OmniRTA](https://appshunter.io/ios/app/omnirta/id6804323641)
- [CipollaMatrix - Psychologie](https://appshunter.io/ios/app/cipollamatrix-psychologie/id6809994424)

All apps by Olivier ADAM: https://appshunter.io/developer/6804323644

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-09.*