[LAD] ambisonics UHJ encoder

fons at kokkinizita.net fons at kokkinizita.net
Wed Feb 24 22:39:48 UTC 2010

On Wed, Feb 24, 2010 at 09:04:37PM +0100, Jörn Nettingsmeier wrote:

> you have to create the illusion
> manually, with delay, eq treble rolloff to simulate air-damping, and
> more reverb (unless you're mixing an outside scene). in theory, HOA
> could do distance coding, but i don't know how to do that, yet. fons
> might be able to point to some information, but i doubt it would be
> worth the trouble at this point, as it's mostly about proximity effect
> anyways (i.e. bass boost for close sources)...

Absolutely correct. The simple fact is that the direct
sound of a REAL sound source doesn't contain any usable
information about its distance at all (apart from HF
damping), unless it is *very* close. 'Close' is expressed
in wavelenghts, so any near-field effect will show up only
at low frequencies.

Except for very near sources, all distance perception in
practice is the result of the sound interacting with the
environment which will add reflections, and in confined
spaces also reverb. To recreate a sound scene from scratch
you have to add these as well to your mix, and with the
correct timing.

Adding just the early reflections, even without any
obvious reverb effect at all, can make a mix 'glue
together' by providing a subconscious reference frame
to the listener. Julien's latest piece is a good 
example of that - just adding the early reflections
of the CdS concert hall with jconvolver makes for a
much more 'consistent' sound without altering the
character of the mix.  



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