FreqCheck™

At rest, the display holds at true zero. No noise. No drift. No false signal pretending to be data.

Then you tap LIVE — and the engine doesn't estimate, it locks. A full waveform renders instantly, meters snap to position, and the same 32,768-point FFT mathematics used in rack-mounted laboratory analyzers runs silently in the background of a device already in your hand.

That means the gap between "I think I hear something" and "I can prove what's there" collapses into a single tap.

Every reading starts the same way: point, tap, see the truth. But not every situation calls for the same depth of control, so FreqCheck no longer forces a single posture on every user.

Instrumentation Settings now houses a single toggle — Pro Input Mode (PIM) — sitting exactly where sensor configuration used to live. Leave it off, and FreqCheck remains the streamlined scanner it's always been: point the built-in microphone, tap LIVE, get your answer. Switch it on, and the same screen where your signal score used to sit transforms into a live metrology configuration snapshot, giving you direct, manual command over the variables that used to belong exclusively to bench equipment.

That means the same app in your pocket adapts instantly to whoever is holding it — a curious homeowner one moment, a certified field metrologist the next. This architectural shift establishes FreqCheck as the first and only Class 1 Mobile Lab App.

ONE APP. EVERY LEVEL OF RIGOR YOU'LL EVER NEED.

Flip Pro Input Mode on, and standard mobile audio filters, automatic gain control, and heuristic smoothing step aside completely. Nothing sits between your sensor and the engine anymore. What reaches IND CORE™ is raw, linear, unadulterated data — exactly the resolution pure metrology has always demanded.

That means the numbers rendering on your screen are the numbers your hardware actually produced, with nothing softened, corrected, or guessed at in between.

Sample Rate, Locked to the Clock You Choose

PIM forces the iOS audio session to handshake with external hardware at strict, selectable rates — 44.1 kHz, 48.0 kHz, 96.0 kHz, or 192.0 kHz — while FFT bin resolution scales automatically to match whichever clock you set. That means your calculations stay anchored to true NIST-traceable precision no matter which piece of hardware you connect.

Manual Calibration, Entered by Hand

ADC voltage ceilings, sensor sensitivity coefficients, and acoustic offsets are now yours to enter directly, right on the same screen where your live snapshot lives. That means your mobile readings scale to match laboratory bench equipment precisely, down to the sub-Hz decimal.

Traditional acoustic analysis has always meant the same tour: a specialized microphone, an external ADC, a desktop application, and an exported CSV file that anyone downstream could alter without a trace. That workflow was built for an era when this level of computation didn't fit in a pocket.

FreqCheck replaces the entire chain with one edge-computing engine. The IND CORE™ architecture performs the identical mathematical rigor of hardware costing tens of thousands of dollars, running natively on iPhone, iPad, and Mac — with Pro Input Mode now bridging directly to that same professional hardware when you need it, and sealing the output the moment it's generated, not after it's already left your hands.

FreqCheck doesn't require industrial equipment — but it doesn't ignore it either. Pro Input Mode natively bridges to professional external DAQ hardware and class-compliant USB interfaces through direct, DC-coupled line-in inputs, accepting calibrated telemetry with zero attenuation and no translation layer in between.

That means a solo field investigator and a structural engineering firm running six-figure sensor arrays are both running the exact same certified analysis engine underneath, with your lab-grade sensors speaking directly to your phone.

Every uncompressed and lossless audio or video file sitting in someone's archive — recordings, exports, old lab captures — has always contained more truth than the tools available to read it. The offline media engine has been rebuilt to mirror the live PIM pipeline exactly, ingesting professional-grade lossless formats directly into the IND CORE™ engine with full amplitude integrity and dynamic sample rate decoding.

That means a file recorded years ago on completely different equipment now gets measured against the exact same mathematical standard as a live capture taken this second — the math is identical whether you're capturing live or auditing a file.

Every measurement FreqCheck produces now passes through an added layer before it ever reaches sealing: your exact hardware parameters — sample rate, ADC ceiling, sensitivity, offset — are captured on a read-only metrology configuration snapshot and permanently stamped onto every PDF export.

From there, it passes through the same three sealing layers as before: anchored to your specific device's verified hardware signature, mathematically sealed with a unique SHA-256 hash tied to your session telemetry, and exported as a digitally signed PDF that invalidates itself the instant anyone tampers with it.

That means the report in your hand isn't a summary of what happened, and it isn't a reconstruction after the fact — it's a forensic record of the exact conditions under which it was captured, carrying the same evidentiary weight as a controlled lab result.

IF SOMEONE QUESTIONS YOUR DATA, THE DATA — AND YOUR SETUP — ANSWER FOR THEMSELVES. Understand the Three-Layer Architecture → Enterprise Compliance

A single reading is a data point. Thousands of cryptographically sealed readings, shared and cross-referenced across a network of field investigators, engineers, and researchers, is a map. The Nyquist Forum is where individually captured telemetry becomes something bigger than any one device could produce alone — guided by Nyquist, the integrated assistant that helps interpret FFT bin behavior and uncertainty margins in plain terms.

That means your local reading contributes to — and benefits from — a growing, cryptographically verified body of global signal data.

FreqCheck's underlying DSP architecture is independently calibrated against exact NIST-traceable SI unit benchmarks by Florida Standards Laboratory under ISO/IEC 17025:2017 (Certificate #05122C9A 2602), with every systematic algorithmic offset publicly documented rather than hidden. All signal processing happens 100% locally — nothing you capture is ever uploaded, stored, or seen by anyone but you.

That means whether you're a metrologist defending a report in front of a regulator, a field investigator bridging in dedicated DAQ hardware, or someone just trying to understand a sound in your own home, you're working from the same uncompromised, private, independently verified engine.

Establish The Standard.