ABX vs Proof Audio Analyzer

Can you actually hear the difference between lossless and the streams you pay for? ABX finds out the fair way: blind, loudness-matched and scored with real statistics. STREAMING CHECK Pick a track and the services you want to test. ABX encodes the lossless original the way each service streams it (Spotify Premium, High and Normal, Apple Music, YouTube Music and SoundCloud), matches the loudness and hides which is which. You hear A, B and X, and decide whether X is A or B. At the end you get a plain answer: which streams you could hear, and which sounded lossless to you. A FAIR TEST • Loudness-matched, so volume can never give the answer away • Seamless 20 ms crossfades, so a click can't either • X is chosen at random for every guess, and services are shuffled together • Every verdict is a one-sided binomial test, and ABX tells you honestly when a score is consistent with guessing • Exclusive output on Mac takes sole control of your DAC and matches its sample rate HEARING TEST How high can you hear? An adaptive audiogram measures 13 tones from 250 Hz to 20 kHz in each ear. See every reading with a smoothed average, your highest tone in each ear and an indicative hearing age. Levels are relative to your headphones: it's for curiosity, not a medical test. YOUR RESULTS, EXPLAINED • A streaming map of what you can and can't hear • A summary written for you on your device by Apple Intelligence (on supported devices) • Free PDF reports and share cards with every setting and score LISTENING NIGHTS Run a session for your audio club, hi-fi store or friends. Name each listener, keep the same track and services for everyone, and get a group report showing who heard what. FREE, WITH ABX PRO Free: the hearing test, plus a full blind Streaming Check against SoundCloud's 64 kbps stream using the included public-domain recordings. ABX Pro is a one-time purchase, with no subscription. It unlocks: • Every streaming service in one blind session • Your own music: WAV, AIFF, FLAC or Apple Lossless, including hi-res • Advanced codec ladders: MP3, AAC, HE-AAC, Opus and Vorbis from 320 down to 32 kbps • Group sessions and group reports • 3 to 10 guesses per service, exact re-runs and exclusive output on Mac One purchase covers iPhone, iPad and Mac, and works with Family Sharing. PRIVATE BY DESIGN Encoding, playback, statistics and reports all run on your device. No accounts, no ads, no analytics. Spotify, Apple Music, YouTube Music and SoundCloud are trademarks of their respective owners. ABX isn't affiliated with them; each preset uses the service's published codec and bitrate.

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.