4 ms·
That's interesting, the guy says in that post the he assumes the depth modulation is one channel and the side-to-side is the other channel for a stereo recordin
by Nition 10y ago
That's interesting, the guy says in that post the he assumes the depth modulation is one channel and the side-to-side is the other channel for a stereo recording. But actually they're both at 45 degrees[1]. It's a clever system because not only does it encode two channels with some of the "better" side-to-side movement (up/down is harder to get fidelity out of), it comes out that that the sum of the channels causes side-to-side movement while the difference causes up and down, so they play on old mono record players as well.
I wonder what his code actually did, and if maybe he could have got a better result.
[1] http://www.vinylrecorder.com/stereo.html http://www.vinylrecorder.com/stereo.html
- jacquesm 10y agoIt's amazing that someone would go through all that trouble and get that detail wrong. There is also the RIAA correction curve to take care of (that was my first encounter with that acronym). The sound played back is pretty eerie, probably some day some alien somewhere will replay our planet earth gold plated recording like that and wonder why our sound encoding sucks if at the same time we can make spacecraft. See also: http://irene.lbl.gov/ http://irene.lbl.gov/ There was also this: https://en.wikipedia.org/wiki/Laser_turntable https://en.wikipedia.org/wiki/Laser_turntable They were about to go mainstream when the CD happened.
- Nition 10y agoGood point. For anyone who doesn't know about the EQ curve on records, it's basically a big bass cut and a big treble boost. Bass causes huge wobbles in the groove so it's cut, and treble is hard to pick up, so it's boosted. Then you just do the reverse on playback. Also a good point that there's nothing on the Voyager record instructions about this...