Tuesday, October 8, 2019

Monaural into true stereo ?

     Recently, sources that should only exist in mono, such as Decca Audition Tape, BBC and so on, have been released as real stereo.




     Years ago, there was something similar in Yellow Dog's "A-Cam + B-Cam: Stereo At Twickenham, Jan 3rd 1969", but the generation method is quite different.

     In the case of Yellow Dog, the two sources are synchronized so that they sound like stereo. (So-called duophonic stereo.)

Seems that Decca and BBC are created with software (maybe SpectraLayers or XTRAX STEMS 2, etc). The difference is that Decca is fan maid and BBC is made by bootlegger.

     The software can extract specific sounds for each instrument. And if you assign each track to the left and right channels, the actual stereo version will be completed. (However, patience seems to be necessary because the frequency must be found and extracted. )
     And this is most important but unconfirmed.―Whether it is a complete separation. As with noise removal, it cannot be completely removed.
Since various sounds or frequencies are overlapping, there is no way to avoid each other's interference. For example, a Mogg file said to have been extracted from the Beatles Rockband game. It consists of multiple channels / tracks, but when you listen carefully, it is faintly mixed with other instrument sounds.
     This is the difference between real multitrack tape and digital analysis. In the case of the Beatles, since the equipment is old, the sound interferes somewhat from the master tape.

SpectraLayers website

XTRAX STEMS 2 website

iZotope RX 7

deezer/spleeter

     I have tried some of these software.
     SpectraLayers has a GUI similar to Adobe Photoshop, high-performance software, but hard for beginners. Useful for short songs but not for long songs.
     I don't know if XTRAX STEMS 2 is good. Maybe it does a good job, because it's very expensive.
     iZotope RX 7 is very simple and easy to operate. However, if the memory is not 4G or more, it may down.
     spleeter, which is the most convenient and high quality for separating music, but the downside is that it is impossible for amateurs from installation to operation (command method!). All software is excellent, but will evolve more in the future.


     Until now, if there was no stereo recording, we had to listen to a "fake" stereo like the good old American edition.

If such technology is possible ―
Not only "Love Me Do", "P. S. I Love You", "Only A Northern Song", "You Know My Name"... but also all the songs was on TV or radio broadcasted can be heard in real stereo.

     Furthermore, the software allows you to remix by changing the balance of each instrument, create karaoke.

     These artificial materials will continue to emerge. In other words, the original material is exhausted.

Of course, I'm happy to hear them in stereo, but something...
While this technology offers us new enjoyment, it also means depletion of the source.