NAME

       ambdec - Ambisonic decoder for first and second order

SYNOPSIS

       ambdec [options]
       ambdec_cli  config_file

DESCRIPTION

       This manual page documents briefly the ambdec and ambdec_cli commands.

       AmbDec  is  an  Ambisonics decoder for up to 36 speakers. It can be used for both horizontal and full 3-D
       systems of first, second and third order.  The decoding matrices are fully user-configurable. AmbDec  has
       some advanced features not found on most decoders:

       Dual  frequency band operation.  Optimal Ambisonics reproduction requires a different decoder for low and
       high frequencies. This is so mainly because human perception of sound direction uses different mechanisms
       at low and high frequencies.  The crossover filters used in AmbDec are phase-aligned (the two outputs are
       exactly in phase at all frequencies). The combined response  is  equivalent  to  a  first-order  all-pass
       network, which is very probably inaudible.

       Speaker  distance  compensation.   If  the speakers are not all at the same distance to the center of the
       listening area, this must be compensated by including the right delays and gain corrections.

       Near-field effect compensation.  Ambisonics works by reconstructing the spherical harmonic components  of
       a  sound  field  at  the center of the listening area, using all speakers to synthesize each of them. All
       non-zero order components show a near-field  effect  depending  on  the  ratio  wavelength=distance,  and
       increasing  for  rising  order.  One  example of this is the well known 'proximity effect' of directional
       microphones ('directional' is equivalent to 'using non-zero order  components').  Except  in  very  large
       installations,  where the speaker distances will be large enough so the listening area is not in the near
       field, this effect must be compensated for in order to obtain a correct reconstruction of a sound field.

OPTIONS

       ambdec accepts the following command line options:

       -h     Show summary of options.

       -c FILE
              Load configuration from FILE.

       -p PATH
              Load presets from PATH.

       -V VOLUME
              Set initial volume in dB.

AUTHOR

       ambdec was written by Fons Adriaensen <fons@kokkinizita.net>.

       This manual page was written by Alessio Treglia <quadrispro@ubuntu.com>, for the Debian project (and  may
       be used by others).

                                                   2010/03/14                                          AMBDEC(1)