[LAU] Panning based on Haas effect

[Fons Adriaensen]

On Sat, Jan 19, 2013 at 12:57:31PM +0100, Jaromír Mikeš wrote:
> 2013/1/19 Fons Adriaensen <fons at linuxaudio.org>:
> > On Sat, Jan 19, 2013 at 12:34:57AM +0100, Jaromír Mikeš wrote:
> 
> Hi Fons,
> 
> > If 'panning' means 'to create an apparent source direction between
> > two (or more) speakers', then whatever you obtain by using such
> > small delays has nothing to do with the Haas effect.
> >
> > Using small delays (< 0.6 ms) works well for headphones, as can
> > be expected - a real off-center source produces the same. It can
> > produce some spatial effects on a speaker system iff the speakers
> > are close to the listener, e.g. the typical multimedia pair sitting
> > besides a computer monitor. But it doesn't scale to larger setups
> > where most listeners can't be expected to be exactly on the center
> > line.
> 
> Exactly! Using of this kind of "delay / Haas based panning" would
> improve one big problem on larger setups.
> 70% of audience on larger setups are out-of-center and 20% percent are
> so much out of center that they can't hear audio signal from more
> distant speaker
> (because of distance and maybe also because of angle).

You seem to read the opposite of what I wrote :-)

Using delays could ensure that e.g. a sound that is supposed to be at a
particular speaker remains there even for a listener who is closer to the
other speakers which get a delayed signal. But that is not panning, it's
just assigning a sound to a particular speaker direction while using the
others to make it louder, or ensuring that the original (direct, not
amplified) sound determines the apparent direction. Such things are
routinely done in e.g. theatre sound amplification. But you can't create
stable images *in between the speakers* by using delays. 

Another thing that can be done while mixing is adding early reflections
(20..80 ms) at a *low* level - this tends to reinforce the effect of the
ampltiude based panning which still determines the apparent direction.
 
> If this kind of "delay / Haas based panning" would be used there would
> be great mono compatibility.

On the contrary, it creates havoc (heavy comb filtering) if the channels
are mixed. Mono compatibility is lost unless you're very careful. It is
possible to create L/R IR pairs that add delays but do not have this
problem, but you don't get those by chance.


Ciao,

-- 
FA

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