7
The Audionet DAC has a software-controlled digital-filtering unit. The
calculating is done by a signal processing system. The tonal differences
between the filters allow you to adapt the sound to your individual
requests. Further the filters can be exchanged.
Following you have a list of the available digital filters.
The diagrams (appendix) show you the attenuation characteristics as well
as the impulse response of each filter.
A long standard filter according to Kaiser with high stop-band
attenuation (>20 kHz) and linear frequency response, therefore long
transient and ringing time.
A short filter according to Kaiser with lower stop band attenuation and
light attenuation for high frequency (above about 17 kHz), therefore
shorter transient and ringing time.
Combined Audionet filter with adequate stop band attenuation and linear
amplitude response (<22 kHz). Short transient time above 20 kHz
because of renunciation of linear phase response.
Short filter according to the principle of the Lagrange polynoms,
therefore other weighting of the stop band attenuation. Has a very direct
impulse response.
Equiripple filter of medium length according to Remez with constant stop
band attenuation and linear amplitude response up to 20 kHz.
Standard filter according to Blackman with useful stop band attenuation
(high attenuation for signal frequencies with statistically high amplitude).
Same length as filter 5, but minor different transient and ringing time.
Digital filtering
Filter 1
Filter 2
Filter 3
Filter 4
Filter 5
Filter 6
