Stereo Difference / Inversion

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I was skimming through YouTube and came across this account.
http://www.youtube.com/user/stereodifference
Instead of describing it myself, here's his explanation:

The audio content concentrates on finding the stereo difference of music. This is done by taking the digital stereo file from a CD in lossless format, then converting this into mono. However, one channel is inverted, thus subtracting the audio content panned dead center of the mix. Removing this will therefore present only certain parts of the mixdown as heard normally on the CD and can sometimes be very interesting, or on the other hand be very dull, depending on how the music was mixed.

Being keenly interested in music production, I immediately knew I had to try this out for myself. I did:
http://www.youtube.com/user/Squishypuff ... ature=mhw5 (in my most recent videos)

Enjoy. I know I did!

hafler circuit for surround extraction

the above circuit description goes a step further and extracts ambient surround information ["stereo difference"] for assignment to rear speakers, passively without requiring any other equipment other than a speaker wire.

me again
various audio wave editors such as soundforge, adobe audition, goldwave and dcart also allow you to parse a stereo waveform into its difference/sum components for remixing. soundforge has the advantage of being able to do this several ways.

Thank heaps!

I've just uploaded another one (Televators, The Mars Volta) Got any song recommendations?

sorry, my tastes in music are a bit provincial compared to yours, i can only tell you that i last did this with 2 versions of a patsy cline song, "san antonio rose" to mash them up into one enhanced version. this was also done with "billy jean" [m. jackson] and "do it again" [steely dan] on a commercial CD.

Although some amps might have problems with this...
simply connecting just one speaker between two outputs
was the old way of getting the stereo difference.
I think it also makes obvious any binaural beat type
subliminals which are made the same way as stereo
but too unnatural to happen by themselves.

good points, some old tube amps with a common ground between the channels weren't amenable to this technique. but extracting subliminals this way is an idea.

I used to do this a little bit in order to extract a sort of 'acapella' out of some songs.
From my experience, it works best on older tunes, from the early 90's and backward, where the mixing is a little more standardized. But I could be wrong in that impression.

your impression is quite right
20 years ago, was the advent of new digital tools to revitalize old mixes and enliven new ones, but these had the side-effect of smearing the phase of solo instruments normally panned centrally, resulting in bleed-over into the difference/surround "channels" [via difference extraction, dolby surround, et al], which ruined any chance at isolating vocals for individual processing after the mix. so older recordings more than 20 years old are amenable to this treatment, but not the lion's share of newer recordings, unless they were simply done ["unplugged" style].