OCTAV — SPL Meter, RTA, Tuner

OCTAV is an instrument panel for working sound engineers: a calibrated SPL meter, a 31-band RTA, a chromatic and drum tuner, and a tone and noise generator, all on one device, all running locally. The SPL meter is built for real work. A/C/Z weighting, Fast and Slow time constants, Max/Min/Peak holds, Leq, and a rolling 60-second history graph give you numbers you can defend. Mic calibration offsets and saved input profiles keep readings consistent across venues. A NIOSH noise-dose clock with escalating hearing-damage alerts is included and never gated behind a paywall — safety instrumentation should not be sold. Tuning covers more than pitch. The chromatic tuner handles any instrument, while the drum tools add a kit calculator, target pitches per drum, and lug-by-lug matching that shows exactly which lugs are out and by how much. The tone generator produces sine, square, triangle and saw waveforms with frequency sweeps and click-free parameter changes, useful for line checks, alignment, or ear training. Pink, white and brown noise generators are included for driving a system during soundcheck. The 31-band third-octave RTA runs at 24 fps with peak hold, and the built-in feedback finder names the ringing frequency and tells you the exact cut to make. A soundcheck library gives per-source starting points — high-pass corner, EQ moves with the reasoning behind each, gate and compressor values, and the combined curve. For deeper work, OCTAV includes a Chladni plate cymatics simulation you can drive with any frequency and export in 4K, along with ear-training games, a hearing check, and an instrument frequency map. The SPL meter, tuner and tone generator are free and permanently ungated. There is no account, no login, no analytics, no tracking, and no data collection of any kind — everything runs on-device, with optional private iCloud sync that stays off unless you turn it on. The interface is a dark instrument panel, with a Show Mode amber palette for working dark venues. OCTAV PRO — WHAT IT COSTS AND WHAT IT UNLOCKS The 31-band RTA and feedback finder, drum lug matching, 4K cymatics export, Show Mode, the soundcheck library and multiple saved shows require OCTAV Pro, an auto-renewing subscription: $8.79 per month, or $39.99 per year with a 3-day free trial. Payment is charged to your Apple ID at confirmation of purchase. It renews automatically unless cancelled at least 24 hours before the end of the current period, and you can manage or cancel it at any time in your Apple ID settings. Download OCTAV and put real instrumentation in your pocket. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://skeptical.agency/privacy-policy