> > Message: 14 > Date: 06 May 2011 07:12:21 +0100 > From: dave.mal...@york.ac.uk > Subject: Re: [Sursound] Question regarding UHJ Encoding - Decoding > To: Surround Sound discussion group <sursound@music.vt.edu> > Message-ID: <prayer.1.3.2.1105060712210....@webmail4.york.ac.uk> > Content-Type: text/plain; format=flowed; charset=ISO-8859-1 > > On May 5 2011, Richard Lee wrote: > >>> This sqrt(2) factor is an endless source of confusion. It seems silly >>> that W should be divided by sqrt(2) in recoding to restore its value, >>> which was multiplied by this in the encode to UHJ. >> >> This sqrt(2) factor is WRONG. Where do people come up with such myths? >> > > I think the problem stems from the early material on Ambisonics in that > sometimes the pragmatic engineering decision to use -3dB on W to equalise > average channel levels on a recording of a reverberant environment with a > large number of distributed sources was rolled into the en/decoding > equations and sometimes (in the more "correct", theoretical discussions) it > wasn't. I remember being thoroughly confused by that way back in the days > of my youth...
I think it more likely comes from there being two versions of the equations, one encoding from b-format and the other in kernel form. The casual reader tends to confuse the direction cosines with the x and y of b-format, MAG usually gave both versions in internal documentation as he worked using the kernel form himself. Geoffrey -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20110506/03a2a192/attachment.html> _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
