|Thanks to optimized algorithms,
it is possible to perform and display simultaneous multi-band
mapping in addition to single-band mapping. In this case,
adjacent frequency bands are displayed in multiple maps.
|This allows a wide frequency
range to be analyzed in a glance.
|The user can select the
upper and lower cut-off frequency. HEAD VISOR then calculates
a logarithmic distribution of the frequency bands for
each multi-band mapping.
|The subdivision is independent
of the frequency band selection for the single-band mapping.
| Example showing the dynamic
range of an application case in the configurable frequency bands
|A central term in array technology
is the dynamic range in the source map. This dynamic range is
a characteristic of the beam forming algorithm and should not
be confused with the dynamic range parameter of microphones
or signal conditioning.
|HEAD VISOR (microphone + conditioning
+ A/D conversion) has a signal dynamic range of 100 dB within
a level range of 30dB to130dB SPL. The dynamic range of each
individual source mapping is about 13 dB.
|This limitation is determined
by the microphone array geometry and the employed beam forming
algorithms and only applies to sources emitting sound in the
same frequency range. This limitation can be avoided by using
multi-band mapping. In this display mode, sources emitting sound
in different frequency ranges are shown in different multi-band
maps, utilizing the full dynamic range of the system.