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View Full Version : FM or TV Spectrum/Frequency?


NoddingTurdFAN
2005-04-30, 07:51 PM
Whaddya think? The dip happens at about 15.5Khz...then there's a spike at around 17Khz then low level action from that point on. No complete loss which would negate MP3 correct? This show is from 1992 and supposedly pulled from a Silver CD boot. Trying to learn this stuff here....

Thanks,

E


Here's a 2 sec view with Freq and Spec and full view of one track w spec and freq.

Five
2005-04-30, 09:51 PM
The spike up at 17kHz makes it look like FM/TV. The cutoff at 15kHz is also characteristic of FM/TV, and I can't see any "blocks" when zoomed in so it looks lossless to me. And yes, mp3-sourced stuff usually has absolutely no activity above the cutoff.

4candles
2005-05-01, 02:00 PM
FM always has a spike at 19KHz - so this isn't FM.

I think I recall people on this forum saying that analogue TV audio has a spike at around 16KHz, but as I live in the UK (where TV audio has been digital for the past 20 years), I don't know anything about that. Hopefully someone that does know will confirm that.

Dave.

ssamadhi97
2005-05-01, 07:36 PM
It's pretty odd, that's for sure.. from the looks of it the stuff above 16kHz might actually be stray aliasing from a 32kHz > 44.1kHz resampling operation (for whatever reason that might have done)

Actually that'd make sense to some extent, too. First recording broadcast audio (which is limited to 16kHz anyway) to 32kHz DAT, then upsampling for cd reproduction.