[Vorbis-dev] 5.1 surround channel coupling

[Ralph Giles]

On Thu, Mar 01, 2007 at 10:30:22AM +1000, Richard Lee wrote:

> There is a large library of impressive uncompressed high quality Ambisonic recordings at 
> 
> www.ambisonicbootlegs.net

Thanks, I'm downloading a couple. That's not the same as 5.1 mixes 
though.

> No.  Ambisonics is definely NOT based on quad.  That's why it works (even with 4.0) when quad doesn't.  In fact Ambi 4.0 works better than 5.1

I do understand that ambisonic encoding is more efficient, but there
can definitely be more information in a 5.1 mix than in a 4 channel 
ambisonic mix. In particular, I don't see how you can localize audio 
across the (film) screen as accurately without including some l=2 modes.

> But the really useful trick is that we can translate 5.1 to 3 channel B-format and if played back on eg an Ambi 4.0 system, might even sound better than the original.

See, here's where you start sounding like an audiophile instead of an 
engineer. :)

 -r