DeHum vs Proof Audio Analyzer

The buzz under your recording has a name: mains hum. DeHum finds the 50 or 60 Hz hum and its harmonics and removes only those — so the voice, the guitar and the room stay exactly as you recorded them. Every repair runs on your iPhone. Nothing is uploaded, ever. ▸ WHAT DEHUM ACTUALLY FIXES The steady electrical drone from bad grounding, a cheap interface, a dimmer switch or fluorescent lights. • Ground loop hum — the low drone from a bad earth connection • 50 Hz and 60 Hz — found automatically, and both at once if your file has both • The harmonics too — 120, 180, 240 Hz and up, not just the fundamental • Hum that drifts — a wandering generator is tracked, not notched around ▸ IT SHOWS ITS WORK DeHum tells you what it found before it changes anything. • Spectrum view — every detected harmonic marked on the graph • A plain reading — "Found 60 Hz hum, 7 harmonics, −26 dB" • A/B toggle — both versions play the whole time, so switching never jumps • It says no — no mains hum, no change, and it tells you why ▸ WHY NOT JUST A NOISE REDUCER Broadband noise reduction treats a narrow defect as a wide one, and the voice pays for it. • Hum is a set of pure tones at known frequencies — DeHum subtracts those tones • Nothing else in the band is touched, so no underwater or robotic artefacts • A stationarity limit caps how much can be removed, so speech is not eaten • Gentle, Standard or Aggressive depth when you want to decide yourself ▸ ON YOUR DEVICE, FULL STOP No upload, no account, no sign-in, no server, no queue. • Works in airplane mode • Your recordings never leave your iPhone — our privacy label reads Data Not Collected • No per-file cost and no credits, because there is nothing to pay for • Import from Files, from Photos, or straight from the share sheet ▸ WHEN THE REPAIR IS DONE • M4A to share, or WAV for exactly what DeHum produced • Video in, video out — the picture is untouched, only the audio is repaired • Batch — hand it a session and each file is checked on its own • Everything lands in Files ▸ DeHum ▸ Exports, and in History ▸ FREE • Hum detection, the spectrum and the A/B on any file • The first 30 seconds repaired at full quality • The audio is never watermarked, on any tier — the free tier is capped by length, never by quality PREMIUM SUBSCRIPTION DeHum Premium is available with the following subscription options: Premium Monthly: $7.99/month Premium Annual: $39.99/year — includes 7-day free trial Premium unlocks full-length files instead of 30-second clips, Gentle/Standard/Aggressive depth control, repairing the audio inside a video, batch processing and WAV export. Payment will be charged to your Apple ID account at confirmation of purchase. Subscription automatically renews unless canceled at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours prior to the end of the current period. You can manage and cancel your subscriptions by going to your App Store account settings after purchase. Terms of Service: https://dehum.bulpara.com/terms Privacy Policy: https://dehum.bulpara.com/privacy Made by Bulpara. Questions: https://dehum.bulpara.com/support

Open Proof and ten instruments run on whatever input you have: RTA, oscilloscope, spectrogram, XY scope, signal generator, SPL meter, level meter, LUFS meter, dosimeter and a transfer function. No account, no trial clock. That half is free and stays free. MEASURING IS THE PAID HALF, AND THE POINT OF IT IS THAT THE RESULT LEAVES A four-second log sweep, separated into the fundamental and its harmonics by Farina's method. What you get back is a file, not a screenshot. Records are plain readable text with a content hash, re-hashed on open rather than trusted: an edited record says so and is refused rather than drawn. Anyone can open and verify one free, paid or not. Export the record, or on the Mac as text or CSV, into REW, a spreadsheet or a driver tool, with the floor beside every value. So a result can be handed to a client or a colleague, and they can check it themselves. WHY THE NUMBERS ARE WORTH HANDING OVER Before it measures your device, Proof measures your interface: its own noise and distortion, frequency by frequency. Every reading is then held against that floor. Clear of it, you get a number. Near it, a range, never a plus-or-minus: a floor can only push a reading up. At or under it, an inequality with no digits: "quieter than this instrument can hear". Significant figures are derived, not chosen: four figures means the instrument is entitled to four. LIVE • RTA: fractional-octave spectrum, bars or line, A/C/Z weighting, averaging, peak hold • Oscilloscope: triggered, with source, slope and level on the graticule • Spectrogram: a colour map monotonic in lightness, so brighter is louder • Signal generator: sine, sweep, pink and white • XY scope: Lissajous and correlation. One channel in this version • SPL meter: A, C or Z weighting, fast or slow, with Leq and max • Level meter: peak and RMS in dBFS • LUFS meter: momentary, short-term and integrated, ITU-R BS.1770-4, gated to EBU R128 • Dosimeter: dose and projected 8-hour TWA, 85 dBA, 3 dB exchange • Transfer function: magnitude, phase and coherence; the trace stops where coherence fails rather than thinning MEASURE • Frequency response, bounded by the measured noise spectrum rather than the distortion floor, because a level is not a ratio • Harmonic spectrum, H2 to H5, each point bounded by the floor at its own frequency • THD against frequency, with the floor for a sum of orders raised the way a power sum requires • THD against level: a sweep per rung, unbounded because a floor from one drive is wrong at both ends of a ladder • The impulse response, and from an acoustic capture its energy-time curve, RT60 per octave band and cumulative spectral decay • Impedance against frequency, through a sense resistor whose value you measure • Microphone calibration from a miniDSP or REW file, corrected at each harmonic's own frequency, with the capsule serial and file hash in the record • A trust tier (Unverified, Floor measured or Calibrated), computed on every read, never stored, so a file cannot claim one it has not earned • A library that browses, verifies, compares and exports THE LIMITS, NAMED • All nine lenses compute. ETC, RT60 and waterfall want an acoustic capture, meaning a microphone with its calibration file loaded; impedance wants a sense-resistor jig. Each says which, and why • SPL reads dBFS until you calibrate against a 94 or 114 dB reference; the dosimeter shows nothing until it does • On a rig with two uncorrected clocks Proof does not report phase or arrival time, and says so • The signal generator writes into whatever you have connected. It is the only tool here that can do damage Proof connects to the App Store for your purchase and to nothing else. No account, no analytics, no crash reporting. Nothing you measure leaves your device unless you export it. Records go to a Proof folder in Documents, reachable from Files. Mac, iPad and iPhone are one app: buy once, use all three. A swept measurement wants an interface you can loop back.