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       ambdec - Ambisonic decoder for first and second order


       ambdec [options]
       ambdec_cli  config_file


       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 feautures 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.


       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.


       ambdec was written by Fons Adriaensen <>.

       This     manual     page     was    written    by    Alessio    Treglia
       <>, for the Debian project (and  may  be  used  by