> 
> Message: 10
> Date: Tue, 10 Jan 2017 08:42:43 -0000
> From: "Alan Varty" <alan.va...@talktalk.net>
> To: "Surround Sound discussion group" <sursound@music.vt.edu>
> Subject: Re: [Sursound] The BBC & Quadrophony in 1973
> Message-ID: <26495940C1B04DA6B9C600AD83F69931@AlanPC>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>       reply-type=response
> 
> I think I am correct in saying the BBC (H) and NRDC (45j) decided to
> co-operate rather than have yet another two competing systems on
> the 4-channel scene which at the time already had CD-4, UD-4, SQ and
> QS in the arena.  BBC/NRDC each modified their encoding "towards"
> each other and called it HJ.

As I recall, the BBC were getting bad reviews of the stereo produced by matrix 
H and discussed this with MAG who proposed a compromise. UHJ was a variation 
within the 5 parameters which define an Ambisonic encoding, mainly a reduction 
in the centre front phase shift compared with 45J, based on many listening 
tests. It was known internally as 35JA’, so you can guess there was a whole 
family of small variations. BBC HJ was defined as a set of tolerance zones on 
the locus, mainly defined with reference to pairwise panning, I think it 
coincided with the UHJ locus at four points , so in that sense it was 
compatible; the exact parameters of both variations were defined by MAG. In 
subsequent tests the BBC made, primarily using SFMs, they also used our 
encoders, so I suspect drama productions such as Gilgamesh and Inferno 
Revisited are actually UHJ.

Geoffrey


_______________________________________________
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.

Reply via email to