I bought and ripped Vienna Teng's CD "Warm Strangers" a while ago, and while I was editing a track in Audition, I noticed two FM signals in the upper frequencies of the CD:

This is in a silent portion of the CD, although it is present throughout the CD. Anybody seen this before?

The CD has no copy protection (and actually has the DCP flag set!), so the only things I can think of are
1) an audio fingerprint or
2) a misguided attempt at noise-shaping.
I don't think it's a piece of equipment that made it, as it is present and constant throughout the CD (even in the 20sec. silence before the "secret" track)

Thanks

I dunno, but I gotta say that it looks pretty cool. Have you tried downshifting it and listening to the signal?

Care to post a 30 second WAV sample so somebody can try to figure it out?

I'm gonna guess that is actually the pilot tone from a tv or monitor used in the studio that was picked up by the mics

Whatever it is, that is pretty cool..

Here's [flac,336K] the 20-seconds that comes before the "hidden" track.

And here's [vorbis,122K] an audible sample I made by setting the sample rate to 6KHz and amplifying.

@dreamliner:
The problem is that it's consistent throughout the album, even during the padding that I posted above. I doubt they'd actually be recording during those 20 seconds. Perhaps it was mixed analog(ly?) and picked up the noise then. The CD doesn't have one of those "AAD" or "DDD" symbols, so I don't know.

[edit:]
Looks like it's actually digital noise. I subtracted the channels, and got:

Those black bars are digital silence. I wouldn't think an analog noise source would do such a thing.

Hmm... it looks suspiciously like a soundcard signature to me, although that would generally be riding the bottom of the spectrum.

- M.

Soundcard signature? Are you talking about DAC noise, or something else? And why would it be at the bottom of the spectrum?

I'm genuinely curious; this isn't the Spanish Inquisiton.

Probably the wrong term for it... sorry. What I meant was the background/system noiseprint inherent to any computer using a poor soundcard. I've posted an example here, if you want to compare.

- M.

Omion,

It would be consistent throughout the recording if it was all recorded in the same studio. This is not uncommon on OST's where the band/orchestra is in the studio with a monitor in front of them showing the scenes from the film they are playing to.

It could be something like UV22 going wrong?

Cheers,
David.

Thanks David! That's IT! HUZZAH! [does the happy dance]

I went searching around on the internet for more info, and found a sample MP3 of UV22 on the Apogee website. Here's what the MP3 looks like:

Pretty similar, I'd say.

According to the Apogee website, UV22 is "Used on 8 out of 10 hit records." I've never seen it before, and I've looked at the spectra of most of my CDs. Maybe my CDs aren't "hit records".