The data is based on the KEMAR HRTF data provided by MIT, which can be found at
<http://sound.media.mit.edu/resources/KEMAR.html>. The compact measurements
were used. See hrtf_tables.inc for more information.
The filter is only available for stereo output, using a 44100hz playback rate.
Note also that it currently only applies to mono sounds, and the cf_level and
head_dampen config options are ignored while it is active.
