crosstalk cancelation

Hi steve

do you have any information about crosstalk cancelation algorithm developed by Edgar Choueiri ?
I found an outstanding 3dsound using this algorithm.

Please, if you have time, take a look and hear the test on link is:

So how does it work? Conventional stereo recordings already incorporate rich location information, but our ears do not capture it during playback because of what engineers call “crosstalk”: the fact that your left ear hears sound from the left speaker but also the right speaker (and vice versa). This explains why stereo recordings don’t recreate dimensionality as accurately as your ears and your brain hear sound in space. The trick is to cancel the crosstalk without altering the sound quality—something no one has ever quite pulled off until now.

Drawing on some of the math in plasma physics, Choueiri devised a digital algorithm that cancels crosstalk transparently without changing the tonal quality of the sound. The brain naturally does the rest, allowing listeners to pinpoint the original placement of sound in space more like it would if we were hearing the “real thing.” Among efforts to develop 3D sound, Choueiri’s approach is unique in that it does not require specialized playback equipment. The digital filter is designed to work on any stereo recording played through any pair of speakers.

The first is technical. I can’t pretend to be a mathematical whiz by any means, which is to say that it was quite a triumph for me to get through Choueiri’s paper, “Optimal Crosstalk Cancellation for Binaural Audio with Two Loudspeakers.” In it, he goes into great detail about all of the formulas that relate to graphs of frequency response from different types of crosstalk cancellation. It’s very impressive work.

From , i quoted

*Here are some of the key points:

The major problem with most filters for crosstalk cancellation is that they bring with them “spectral coloration” — they boost some frequencies and adversely affect the sound colour of the recording.
As Choueiri says, “the ‘perfect’ [crosstalk cancellation] filter would impose these necessary level boosts only at the loudspeakers in such a way that, at the listener’s ears, not only the crosstalk is cancelled, but also the frequency spectrum is reconstructed perfectly, i.e., with no spectral coloration.”
Other developers (namely, Takeuchi and Nelson) have created crosstalk filters that avoid coloration, but require 6 speakers for playback — immediately pushing away non-audiophile listeners who don’t have a multispeaker playback system.
One of the ways to filter crosstalk is through “constant-parameter regularization,” and while it works fairly well, it introduces significant coloration, especially in bass and high frequency response.
A smoother way to filter crosstalk is through “frequency dependant regularization,” which applies different filter responses to different bands of frequencies. This is what Choueiri has been developing.

What about this as a plugin ?

This technology seems trully amazing.

Here goes his paperwork

Best Regards,


I bet you could get very similar effects with careful matrixing within Audacity. Audacity records music straight from stereo microphones as Left and Right. FM Stereo Radio doesn’t work like that. FM Stereo transmits two signals, but they’re not Left and Right. The Main FM signal is Left and Right added up to make mono. This makes all the non-stereo receivers out there happy. It also transmits a separation signal in a way where only stereo FM receivers can find it. So the trumpet comes down the main channel along with the other instruments, but the separation signals tells the system where it is – say off to the right with all the other brasses.

That process can be a simple arithmetic process within Audacity and once you have the separation signal, you can amplify it and accentuate the separation. In effect, it makes the “width” of the orchestra a user controlled slider and you can make it wider than normal helping with the speaker crosstalk problem.

No exotic software needed and there’s little or no sound distortion.

No good deed goes unpunished, of course, so you need to know that with all these schemes, the effect varies with the speaker and it becomes grotesque with headphones which have no crosstalk at all.