SonoSpec
A real-time audio spectrum analyzer that turns your phone into a beautiful, buttery measurement instrument — see what you're hearing.
Overview
SonoSpec turns your phone's microphone into a real-time audio spectrum analyzer. Built for car-audio tuning, room acoustics, HVAC and machinery noise hunting, speaker testing — and anyone who wants to see what they're hearing.
Under the beauty is a real instrument: a 2,048–16,384-point FFT, dBFS levels against a full-scale-sine reference with window-bandwidth correction, A/C/Z weighting computed per the IEC 61672 formulas, and exact base-10 1/3-octave bands per IEC 61260. Rendering runs on a dedicated graphics path at the full analysis rate, so the traces feel like hardware.
Everything happens on-device. Audio is never recorded, stored or transmitted — SonoSpec has no accounts, no ads, no analytics, and no network access at all. $9.99, one time.
See It in Action
Four Views, One Instrument
Live FFT trace with a slow-decay peak-hold overlay and a log-frequency grid, from 20 Hz to 20 kHz.
Scrolling spectrogram that makes tones, sweeps, rattles and resonances obvious over time.
Spectrum and waterfall together — the everyday tuning view, both representations at once.
31-band 1/3-octave RTA bars per the IEC 61260 base-10 band definitions.
Features
- § 01Four views, one instrument
Spectrum, Waterfall, Split and Octave — switch instantly. Rendering runs on a dedicated graphics path (Metal on iOS) at the full analysis rate, with a phosphor-and-ember look that's readable at arm's length.
- § 02Measurement-grade FFT
FFT sizes from 2,048 to 16,384 points — 5.9 Hz resolution at 48 kHz. Levels in dBFS against a proper full-scale-sine reference with window-bandwidth (ENBW) correction, so the numbers actually mean something. Estimated dB SPL (Android, supported devices): on Android phones that certify the platform's unprocessed-microphone sensitivity spec, switch the level readout to an estimated sound pressure level (±3 dB spec basis) — no external mic or calibration needed.
- § 03A, C and Z weighting
Weighting curves computed per the IEC 61672 formulas, plus exact base-10 1/3-octave bands per the IEC 61260 definitions. Peak-hold trace with slow decay, pause/hold, and a drag cursor that reads out the exact frequency and level under your finger.
- § 04Built-in signal generator
Pink noise, white noise, sine, log sweep and warble tones — the source half of the RTA workflow. Feed the system under test by cable or USB and watch the response live.
- § 05Target curves
Overlay a house curve — flat, −3 dB/oct tilt, or a bass-lifted car target — on the live spectrum. Auto-fit positioning snaps the shape to your measurement, no fiddling.
- § 06Snapshots & export
Freeze a measurement and recall it as a ghost overlay for before/after comparison. Share a publication-ready image or CSV with a full metadata header — FFT size, window, weighting — so your data still means something later.
Measurement & Standards
- ▪FFT resolution
2,048 to 16,384-point FFT with a Hann window and coherent-gain correction — 5.9 Hz per bin at a 48 kHz sample rate. Levels are dBFS referenced to a full-scale sine, with ENBW (window-bandwidth) correction applied so band sums read true.
- ▪A / C / Z frequency weighting
A, C and Z weighting curves computed per the IEC 61672 formulas. SonoSpec is not a certified sound level meter — it applies the standard weighting math, it does not claim IEC 61672 class compliance.
- ▪1/3-octave bands
31-band 1/3-octave RTA using the exact base-10 band-edge definitions from IEC 61260, with per-band power sums.
- ▪Drag cursor & peak hold
A slow-decay peak-hold trace plus a draggable cursor that reads out the exact frequency and level under your finger. Pause and hold any measurement.
- ▪USB audio interfaces
Plug in a USB audio interface and every channel is captured and mixed down for analysis — no external app required.
- ▪Sound-level estimate (Android, supported devices)
On Android devices that certify the platform's unprocessed-microphone sensitivity spec, the level readout can switch to an estimated sound pressure level (±3 dB, spec-basis) — no external hardware. It is labelled an estimate, not a calibrated measurement. iOS reports dBFS only; SonoSpec makes no SPL claims on iOS.
- ▪Private by construction
Audio is analyzed on-device and never recorded, stored, or transmitted. No accounts, no ads, no analytics — the app cannot even access the network.
Honest call: SonoSpec is a measurement instrument, not a type-approved sound level meter. It applies the IEC 61672 weighting and IEC 61260 band math exactly, but does not claim class certification — and it makes no calibrated-SPL claims on iOS.
Frequently asked questions
SonoSpec turns your phone's microphone into a beautiful real-time audio spectrum analyzer (RTA). It shows a live FFT spectrum, a scrolling waterfall spectrogram, a split view, and 31-band 1/3-octave bars — built for car-audio tuning, room acoustics, HVAC and machinery noise hunting, and speaker testing.
SonoSpec is available now on Google Play for Android, and the iPhone version is in App Store review and will release automatically on approval. It's the same instrument on both platforms — the DSP math is identical iOS to Android.
No. By default SonoSpec reads in dBFS (a full-scale digital reference), which is exactly what you want for relative measurement, tuning and comparison. On Android devices that certify the platform's unprocessed-microphone sensitivity spec, the readout can switch to an estimated SPL (±3 dB, spec-basis) — clearly labelled an estimate. On iOS it reports dBFS only. SonoSpec is not a certified sound level meter.
SonoSpec computes A, C and Z weighting curves per the IEC 61672 formulas, and 1/3-octave bands per the IEC 61260 definitions — so the math matches the standards. It does not claim IEC 61672 class certification; it's a measurement instrument, not a type-approved meter.
$9.99, one time. No subscription, no ads, no in-app purchases, no accounts. You buy it once and own it.
Completely. Audio is analyzed on-device and never recorded, stored, or transmitted. SonoSpec has no accounts, no ads, and no analytics — the app has no network access at all.
Yes. Connect a USB audio interface and every channel is captured and mixed for analysis. SonoSpec also has a built-in generator — pink noise, white noise, sine, log sweep and warble tones — so you can drive the system under test and watch the response live.
Availability
- Every view and feature — no tiers, no unlocks
- No subscription, no ads, no in-app purchases
- No account required
- Audio analyzed on-device — nothing recorded or transmitted
- Car-audio tuning — Dial in a system by ear and by eye — with a car target curve.
- Room acoustics — Find room modes, nulls and ringing with the waterfall.
- HVAC & machinery — Hunt down tonal noise and rattles by frequency.
- Speaker & driver testing — Drive with the built-in generator, read the response live.
See what you're hearing.
SonoSpec is a real instrument at a one-time $9.99 — on Google Play now, with the iPhone version in App Store review. No subscription, no account, nothing leaves your device.