SoX - Sound eXchange

I'm trying to revive an interesting discussion about high quality stereo to
mono conversion
(http://www.hydrogenaudio.org/forums/index.php?showtopic=30844):

"If recordings are converted from stereo to mono using traditional methods
(i.e. pressing the 'MONO' button on an amplifier), some sounds will get
lost in the process, making the result sound less 'full' or even distorted.
FlatStereo, a technology created especially for Weird Titan Radio,
completely solves this problem. The sound is converted to mono in two
steps:

* Remove phase shifts between left and right channel.
This results in a recording where each channel sounds exactly the
same as it did before, but a part of the stereo effect is lost. (The phase
for the left and right channel is equalized)

* Convert the two channels to one channel using traditional
stereo-to-mono methods (similar to pressing the 'MONO' button on an
amplifier).
This results in a mono signal, where all sounds from the original
recording are still present."

AFAIK I don't know any open source tool to achieve this, so I hope that SoX
could implement this functionality.

I just remember only one Windows tool (now adbandoned) that does the phase
shift correction: Advanced Audio Corrector by Dmitry Sknarev (check out the
downloadable trial version here:
ftp://freefiles:getitnow@ftp.win-soft.com/Aacorr21Trial.zip)

Hope that helps, or at least inspires !

Marco Radossevich