[Vorbis-dev] Ambisonics in Ogg Vorbis

[Gregory Maxwell]

On 4/27/07, xiphmont at xiph.org <xiphmont at xiph.org> wrote:
> (eg, the FAQ doesn't answer a few simple questions like 'should I be
> using monopole speakers, or are bipoles better like in other
> systems?')

Yech. Other than a few (possibly crazy?) people, no one recommends
dipole speaker for ambisonic playback... they don't work, at least
mathematically.  There has been some argument based on a few people's
experience that in some rooms they might work okay, but it's not
entirely clear why.

Small, full range, flat monitors, are probably best. Small, because
big is the enemy of being able to place them correctly.   Consistent
phase response is important. (i.e. reversing phase on a driver breaks
it completely). Because the goal is to reconstruct the soundfield,
consistent and predictable speaker behavior is useful.

Some have found it advantageous to use digital room correction to get
a more uniform speaker respond and to tame the room's LF behavior
some. Some software for computing correction filters is at
(http://drc-fir.sourceforge.net/). This would hopefully reduce room
sensitivity. YMMV.

You should probably subscribe to the surround list
(https://mail.music.vt.edu/mailman/listinfo/sursound), which is where
a lot of really brilliant people interested in ambisonics hang out.