Hi Marc, Yes, this is very difficult to do properly but a simple bodge is surprisingly effective. Undoing the built in binaural encoding from the original recording is next to impossible.
I have done what is suggested in the ambisonic.net sources in Max. XY or polar coordinates place the left and right channels at variable points on a circle in a 1st order ambisonic encoder, giving a basic B-format output. This image can then be rotated by fairly simple maths to alter the coordinates of both channels together, or by rotating the B-format signal. The rest is done by an ambisonic decoder. Once in B-format, the WXY components can be manipulated; gain, eq, directional dominance. You can also apply a Z coordinate to move the image up and down. The result is undeniably diffuse, but usable. Generally binaural recordings sound OK as normal stereo, obviously without the proper spatial impression. Interesting effects are also achieved by treating stereo as UHJ and deriving B-Format from that. I think there is something on that on ambisonic.net, as well as super stereo and Dolby stereo. Transaural crosstalk cancellation only works over a very small area, and becomes more complex for quad. Many such systems go for some form of closely spaced dipole speaker layout, possibly with extra speakers. The University of Southampton had something like that, but references might take some finding. Ciao, Dave Hunt > On 4 Mar 2021, at 17:00, sursound-requ...@music.vt.edu wrote: > > From: Marc Lavallée <m...@hacklava.net> > Subject: [Sursound] binaural to FOA? > Date: 4 March 2021 at 13:55:42 GMT > To: Surround Sound discussion group <sursound@music.vt.edu> > > > I have a "back to the basics" question. > > For a simple project I planned to record in FOA or HOA, but the final render > would be in simple quad (horizontal). So I don't need a lot of resolution. I > enjoy recording with binaural microphones (the kind that looks like cheap > earbuds), so I can record continuously without being noticed. > > So I wondered; is there a method to "convert" binaural to horizontal-only > FOA? Apparently there is: > > https://www.ambisonic.net/quaduhj.html > > http://www.ambisonic.net/ambimix.html > > I guess my question is: what would be the software equivalent of a pan-rotate > device? > > Marc _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
