Conrad Hoffman said:You guys just don't have any imagination. It could be data of some sort. Secret messages. Something for space aliens to home in on. Maybe watermarking for copyright purposes. Wait, what are those black helicopters bearing down on my house? Argggg...
Conrad
Play it backwards and all will be reveiled.
For the others
Edit it out.
listen to the music again and is there any difference, or what is the difference.
allan
I can't believe that many studuos have noisy ballasts. That type of noise is usually fairly complex with fundamantals well below what I saw. The spectrum is a pure, unwavering, very narrow band spike in the 16 kHz region. CRT maybe, but not ballast. Could some singers use a teleprompter for lyrics, or perhaps a video feed to performers in other booths?
Maybe some downconverting artifact? 16KHz is 1/3 of 48KHz, 1/6 of 96KHz, 1/12 of 192KHz. A lot of digital tape recorders used in studios are 48KHz. Although most new equipment is hard drive based.
Is there anything at 12KHz (Fs/4), 9.6KHz (Fs/5)?
Maybe a poorly implemented dithering/noise shaping algorithm?
Is there anything at 12KHz (Fs/4), 9.6KHz (Fs/5)?
Maybe a poorly implemented dithering/noise shaping algorithm?
High Frequency Spurs ...
I believe it is the 15,750 sweep frequency (in America, in Europe it is different dependent on the local TV System) from monitor in the control room. Monitors radiate both electrostatically and electromagnetically, and shielding can be difficult. I have seen spurs, at about -70db or so, using the spectrum display in Cool Edit (now Adobe Audition) on many discs, and wondered why none of the "Golden Ears" in the press ever mentioned it !!! Could it be Masking ? and if they can't hear 15,750 at -70, do we really need "Ultrasonic" response to 96 Khz ? ...
I believe it is the 15,750 sweep frequency (in America, in Europe it is different dependent on the local TV System) from monitor in the control room. Monitors radiate both electrostatically and electromagnetically, and shielding can be difficult. I have seen spurs, at about -70db or so, using the spectrum display in Cool Edit (now Adobe Audition) on many discs, and wondered why none of the "Golden Ears" in the press ever mentioned it !!! Could it be Masking ? and if they can't hear 15,750 at -70, do we really need "Ultrasonic" response to 96 Khz ? ...
Possible that it happens but you'ld expect to see the phenomena on all music, or at least all music with comparable spectra. Using WaveSpectra, yet another program that shows the 'whistle', it's only on some CDs and the level varies substantially between cuts on which it appears. In retrospect, where would the CRT injection occur? The console? Mastering stage? One thing that argues against it being in the booth is it doesn't appear to modulate with vocals or overall levels. You'ld expect compression and gating to cause all kinds of change if it was being caught by the mic.
I can't think of a way that an artifact like that could be generated by the FFT. Usually, the issues are resolution, bandwidth, and measurement time, not spurs. Poor windowing just distorts already-existing lines. Calculation time is pretty cheap these days so generally doesn't enter into consideration.
My first guess would also be a video monitor somewhere along the line.
My first guess would also be a video monitor somewhere along the line.
Apparently, we are not alone in this:
http://www.audiodesignline.com/showArticle.jhtml?articleID=204700420
This was in today's mail.
http://www.audiodesignline.com/showArticle.jhtml?articleID=204700420
This was in today's mail.
Reply to I_Forgot ...
It may be an artifact of the use of an FFT algorithm in general. It has been a long time since I looked at FFTs, but I seem to recall there are tradeoffs of precision vs. calculation speed that may generate this sort of thing.
I_F
In my experience, the spur just sits there, being obscured by the music and noise as they rise and fall ... And if I point to the spur in the Frequency Analysis, it reports the spur as 15,750 ...
And the story at:
http://www.audiodesignline.com/show...cleID=204700420
reports spurs measured at 19 kHz, the frequency of the FM Subcarrier for stereo FM, so we might be looking at a CD made from a broadcast source or air check through a receiver with poor subcarrier filtering ...
It may be an artifact of the use of an FFT algorithm in general. It has been a long time since I looked at FFTs, but I seem to recall there are tradeoffs of precision vs. calculation speed that may generate this sort of thing.
I_F
In my experience, the spur just sits there, being obscured by the music and noise as they rise and fall ... And if I point to the spur in the Frequency Analysis, it reports the spur as 15,750 ...
And the story at:
http://www.audiodesignline.com/show...cleID=204700420
reports spurs measured at 19 kHz, the frequency of the FM Subcarrier for stereo FM, so we might be looking at a CD made from a broadcast source or air check through a receiver with poor subcarrier filtering ...
I think you are on to something here...hayenc said:
Now, Aphex Twin originally released a series of EP's, called Analord 1,2,3,4 etc. on vinyl
Then, a year or so later, he released 10 of the songs from the EP's on CD, called "Chosen Lords"
Now, I'm not sure if the CD was made from the vinyl or masters, and vinyl has roll off around 16KHz, but I found lots of strange things on this CD.
Also, this could all be one big joke, as if you look at one of the song's on the Windowlicker CD thru the spectrogram, you see his face (attached) so take this with a pinch of salt...
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