[black]Diamond[/black] wrote:
Michael Patrick wrote:
According to my CD copy of the Beatles "Sargeant Pepper" album (yeah, I like both the Beatles and New Order, it's not a big stretch), the original vinyl album had a recording in the center groove so that any record player without an arm that lifts itself off the vinyl at the end of the side would slip into the center grooves and play the recording continuously. The CD ends with several seconds of that loop. (Sure, the thread is about "the first compact disc 'hidden track,'" but it's basically the same idea.) Somehow I doubt the Beatles were first with that idea, though.
Before that, a couple of seconds of a very high-pitched tone that was supposed to be out of the range of a human's hearing. This was supposed to upset dogs, aparently.
Oh those crazy Mop Heads!
(moderate) Horseshit.
As compact disc uses a PCM sampling rate of 44.1KHz, and Nyquist theory states that the highest recordable frequency is precisely 50% of that sampling rate (i can draw diagrams of why if you like LOL). this means the highest sound possible on a compact disc is 22050Hz, which while on the very edge of human earing is not actually completely beyond it (it's only a perfect 5th above the noise of a CRT television's scanner whine). Of course, there are the ringmod side bands that PCM creates, (a constant ring at the sum and difference of the recorded frequency and the sampling rate), but the DAC's filter those frequencies out as they are pointless to out ears.
oh and not many speakers go much about 20KHz.
I believe canine hearing extends nearly an octave about ours....so those of you with Protool or cubase configured for recording at 24bit 96Khz can record dog annoyances (not withstanding there's sod all that will play them back).
End morning technorant.