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View Full Version : How to detect if audio is from a cassette


mrledhed
2011-08-09, 03:33 PM
Is there a way to detect if audio is cassette sourced like we do with mp3?

tonebloke
2011-08-10, 02:36 AM
China is the most eco-friendly country in the world. :lol4:


........oh yeah. No!

Audioarchivist
2011-08-10, 04:35 AM
I dunno what China or eco-friendly countries have to do with cassette rips, but yeah, no, there isn't really a way to detect a tape rip. At least, not some fool-proof automatic way, since even the "automatic fool-proof" ways to detect an eMPty3 aren't quite so fool-proof and precise and perfect anyway!

What's wrong with cassettes anyway? They CAN be pretty good! Really! haha

Good luck!

co9ol
2011-08-10, 06:32 AM
My only guess is to listen for tape hiss? But even still, a recording having hiss doesn't mean it's from a tape.

vladsmythe
2011-08-10, 10:13 AM
Is there a way to detect if audio is cassette sourced like we do with mp3?
Um...hire a mp3 cassette source detective? That's my guess. :lol4:

paddington
2011-08-10, 12:10 PM
yeah, probably a bit of hiss if the tape is 2nd - 3rd gen.

AAR.oner
2011-08-10, 02:17 PM
Um...hire a mp3 cassette source detective? That's my guess. :lol4:

forensic audio analyst...will run ya about $2-4K per recorded hour tho

P A U L
2011-08-10, 06:59 PM
I've got a few raw files from Mike (mikesline) where you could hear the tape flip, because he ejects it while it's still going & hits record as he's cramming the tape in the machine...

Hiss, can be created & various stages/sources. The instrument amps, the PA, the mixer, the recording device. Most digital recorders record native @<hidden> 48/24. When you downsample, you either dither, or get distortion. Dithering is adding noise (comparable to hiss) to keep distortion to a minimum...

mrledhed
2011-08-19, 11:23 AM
but there must be a frequency cutoff isn't there?

co9ol
2011-08-19, 05:46 PM
but there must be a frequency cutoff isn't there?

Yes but i believe that the cut of frequency is different for different kinds of tapes and different kinds of tape recorders. I'd love to see a chart if anyone can find it.

Audioarchivist
2011-08-19, 05:55 PM
I have seen frequency response graph indicating stuff happening up to 240000hz on tape. I've seen one tape I made that has (although it isn't musical) a spike on the recording (not playback interference) - it was around 33000hz!

The tape doesn't necessarily cut off frequencies like a lossy file chops off. More likely the music rolls off at the same rate as the tape does, the same way the mics do...

It isn't as clear cut an issue for tape cut off points as the way an mp3 does it. There are lots of variances that can't be accounted for so easily...

Listen for breaks in the audio where the tape flips would have to be. That's your best clue...