In article <[email protected]>, Owen Smith <[email protected]> wrote: > That's Matrix H, which is the most over complicated matrix encoding quad > ever used. It was impossible to decode at all accurately with 1970s > analogue electronics, and is still extremely difficult with modern > computers. The BBC were definitely mistaken in proposing Matrix H.
> This broadcast is in Matrix HJ, which was a combination of Matrix H and > 45J encoding. This later morphed into UHJ which is a matrix encoding of > Ambisonics which is still in use professionally. IIRC I have a few CDs that nominally use that. Some, I think, are the 'First Voice' series that recorded an acoustic gramophone in a good room! > Doing the phase shifts and basic matrix decoding is easy with computers. > The problem is removing the residual ubbish from the other channels, so > that something appears genuinely in rear right rather than every speaker > except front left. That's damned hard even with modern computers. IIRC some decoders added 'logic steering' to try and guesstimate improvements. But TBH I suspected that by the time it had been though the LP cutting/making process in pre-CD days the actual phases would have been fiddled up anyway. Jim -- Electronics https://www.st-andrews.ac.uk/~www_pa/Scots_Guide/intro/electron.htm Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html biog http://jcgl.orpheusweb.co.uk/history/ups_and_downs.html Audio Misc http://www.audiomisc.co.uk/index.html _______________________________________________ get_iplayer mailing list [email protected] http://lists.infradead.org/mailman/listinfo/get_iplayer
