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Quality Analysis - spotting fake hi-res and fake lossless
Quality Analysis looks inside your files to check whether the audio really is what the label claims. A file can say "24-bit / 96 kHz hi-res" or "lossless FLAC" in its tags while the sound inside tells a different story. This tool reads the actual audio and flags the ones that don't add up.
What it can find
When it analyses a track it gives one of these verdicts:
- Genuine - the audio fills the range you'd expect for its format. Nothing suspicious.
- Suspected fake hi-res (upsampled) - the file is labelled high-resolution, but the audio inside only contains detail up to CD range (or lower). Someone took an ordinary CD-quality (or worse) recording and "stretched" it into a hi-res container. The big number on the label is real; the extra quality it promises is not.
- Suspected fake lossless (lossy source) - the file is in a lossless container like FLAC, but the audio inside was clearly made from a lossy file (an MP3 or AAC) at some earlier step. It's lossless packaging around lossy sound.
- Naturally band-limited - the audio doesn't reach the top of its range, but in a smooth, natural way (for example an older analogue master). This is not a fake - it's flagged as normal so a genuine older recording is never wrongly accused.
- Indeterminate - the file couldn't be analysed (an unusual format, or a damaged file). No judgement is made.
The one people miss: lossless CD that isn't really lossless
It's easy to assume that only hi-res files can be faked. They can't - a fake can hide in an ordinary CD-quality file too, and it's one of the most common problems in downloaded music.
Here's how it happens. A CD-quality FLAC is 44.1 kHz, 16-bit, and lossless - a perfect copy of the source. But someone can take an MP3 (which permanently throws away detail to save space), re-save it as a FLAC, and now the file looks like a pristine lossless CD rip. The tags say FLAC, lossless, CD quality. The file size looks about right. But the audio inside still carries the tell-tale "ceiling" that the MP3 cut off - it was never truly lossless, and re-wrapping it as FLAC doesn't bring back what the MP3 already discarded.
So a file can be shown as CD-quality lossless when it isn't - not because the sample rate is faked (44.1 kHz really is 44.1 kHz), but because the source was lossy. Quality Analysis catches this as Suspected fake lossless. This is exactly why the "check everything" option exists: fake hi-res only lives in files claiming hi-res, but fake lossless lives in the ordinary CD-quality part of your library - the part a hi-res-only scan would skip.
Choosing what to scan
You can run Quality Analysis on a single track, one album, or your whole library.
- Hi-res files only (the default for a whole-library scan) - checks just the files that claim to be high-resolution (above CD rate or more than 16-bit). This is the fast, targeted hunt for fake hi-res, and it skips the CD-quality majority of most libraries.
- Check everything - also examines your standard CD-quality files, to catch the fake lossless case above (a lossy MP3/AAC re-wrapped as FLAC). It takes longer because there are usually many more files, but it's the only way to find lossy-sourced "lossless".
Because analysing means reading and decoding each file in full detail, a whole-library scan can take a while - especially over a network drive. You'll be asked to confirm before a full-library run, and a good first step is to analyse a single album to see how it works.
Honest about its limits
No tool of this kind can catch every fake, and this one is deliberately cautious about accusing your music:
- A very high-quality MP3 can slip through. A top-bitrate MP3 (320 kbps) keeps detail almost all the way to the CD ceiling, so at CD rate it can look genuine. Quality Analysis reliably catches low- and mid-quality lossy sources; a near-transparent one may read as Genuine. This is a limit of every detector of this kind, not just ours.
- It won't wrongly flag a real old recording. A genuine analogue or early-digital master that simply doesn't reach very high frequencies is recognised as naturally band-limited, not a fake.
- It checks frequency content, not bit depth. A file padded from 16-bit to 24-bit ("fake 24-bit") is a different kind of trick that this frequency-based check doesn't cover.
What the verdicts are for
The results appear as an informational category in Library Health, and you can filter your library to show the suspected files. They're there to inform, not to delete anything - Quality Analysis never changes or removes your files. Use the flags to decide for yourself whether to hunt down a better copy of an album you care about.
Quality Analysis is a Lifetime feature.