# Overtone Lab: Acoustics & RT60 — Subwoofer Box, Crossover, LUFS

> Subwoofer Box, Crossover, LUFS (iPhone/iPad app by Koreniuk Oleksandr.)

- Source: https://appshunter.io/ios/app/overtone-lab-acoustics-and-rt60/id6787524729 (this page in markdown: same URL + `.md`)
- Developer: [Koreniuk Oleksandr](https://appshunter.io/developer/1563057206)
- Category: Music
- Price: $9.99
- Age rating: 4+
- Requires: iOS 26.0 · 7 MB
- Languages: American English, Czech, Dutch, French (France), German (Germany), Greek, Hungarian, Italian, Japanese, Korean and 7 more
- Released: 2026-07-09
- Data updated: 2026-08-11
- User reviews in markdown: https://appshunter.io/ios/app/overtone-lab-acoustics-and-rt60/id6787524729/reviews.md

## What is Overtone Lab?

Overtone Lab is a precision calculation studio for musicians, instrument builders and audio engineers — 26 exact tools in one offline app, in seven sections.

TUNING
• Partch — just intonation, cents, nearest just ratio, Tenney height
• Comma — equal divisions (EDO) & historical temperaments
• Mersenne — string tension, frequency & fret spacing

TIMING
• Tempo — note & bar lengths, time↔samples, varispeed
• Delay — tempo-synced delay, distance alignment, comb filtering
• Timecode — SMPTE 24 / 25 / 30 & 29.97 drop-frame
• Pitch — note↔frequency↔wavelength, harmonics, beats, Doppler

ACOUSTICS
• Sabine — room reverberation (RT60), Schroeder frequency, room modes
• Webster — exponential horn cutoff & Helmholtz resonance
• Bernoulli — open/closed pipe resonance & end correction
• Formant — vocal-tract formants & vowel presets
• SPL — inverse-square distance law & source summation
• Room Modes — axial/tangential/oblique modes, Bonello & Sepmeyer ratios
• Air — atmospheric absorption & speed of sound (ISO 9613-1)
• SBIR — speaker-boundary interference & comb filtering

SIGNAL
• Butterworth — filter response & Linkwitz-Riley crossovers
• Fletcher — A / C / Z frequency weighting
• Benchmark — real ITU-R BS.1770 integrated loudness (LUFS) & streaming targets
• Passive — RC / RL / LC filter corners
• Biquad — digital IIR filter coefficients (RBJ cookbook)
• Compressor — gain computer, soft knee & attack/release time constants

STEREO
• SRA — stereo recording angle for mic arrays (ORTF, NOS, DIN, Blumlein)

UTILITY
• Levels — decibels, dBu / dBV, dynamic range
• File — uncompressed size, sample rate & Nyquist frequency
• Pan — equal-power & linear pan law

DESIGN
• Thiele — Thiele-Small sealed & ported loudspeaker enclosures

Every result is computed from published formulas and validated against reference sources. Type any value and the whole screen recomputes instantly.

100% offline — no account, no network, no tracking, no subscription. Buy once, use forever. Universal for iPhone, iPad and Mac.

Estimates for design and study; cross-check critical work against measurement.


## Version history (last 2 releases)

### 1.0.2 — 2026-08-08

Overtone Lab is now on Apple Watch. All 26 calculators on the wrist: turn the Digital Crown to change a value, swipe to page between tools, swipe up for the full list. Tap tempo finally lives where you use it.

Overtone Lab now speaks 17 languages, and numbers follow yours: a German user reads and types 0,81, a Japanese user 0.81 — display and entry finally agree.

New Settings screen (gear, top right) to pick a language, or leave it following your device. All 26 tools, still fully offline, still buy-once.

### 1.0 — 2026-07-28

No release notes.

## More apps by Koreniuk Oleksandr

- [Skyscraper Frog](https://appshunter.io/ios/app/skyscraper-frog/id1563057204)
- [Golden Ratio Tech Calculator](https://appshunter.io/ios/app/golden-ratio-tech-calculator/id1570841203)
- [Golden Ratio Calculator Lite](https://appshunter.io/ios/app/golden-ratio-calculator-lite/id1570956847)
- [Indox Text](https://appshunter.io/ios/app/indox-text/id1603883417)
- [Typing Mill](https://appshunter.io/ios/app/typing-mill/id1631148042)
- [Big Pink Cat](https://appshunter.io/ios/app/big-pink-cat/id6497066161)

All apps by Koreniuk Oleksandr: https://appshunter.io/developer/1563057206

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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 2026-08-11.*