Dsp-Software Audio Analyser; Brief Description And Characteristics; Keyboard Operation - RME Audio ADI-96 PRO User Manual

11. DSP Software Audio Analyser

11.1 Brief Description and Characteristics

The DSP software Audio Analyser transforms the ADI-96 PRO into a powerful Spectrum
Analyser. As opposed to nearly all current PC based solutions no FFT (Fast Fourier Transform)
is used. Although this method needs only little calculation (CPU) power, it offers no useable
translation of sound in vision. The 'bands' of a FFT have a constant frequency distance, which
results in the higher area in numerous bands, but in the lower frequencies in only some bands.
Some manufacturers try to minimize this behaviour, but even then a sine will show an un-
symmetrical display and an insufficient band separation.
The DSP of the ADI-96 PRO performes a real bandpass filter calculation, as usual in all
professional 'Audio Spectrum Analyzers'. The distance between the filters is not linear, but sca-
led according to human hearing. Thanks to the external calculations the Windows software
does only display the results. This allows to run a 30 band Analyser with 50 dB range, sharp
filters and 100 LED's per band even on an older PC, without driving the computer to its limits.
On a Pentium III 800 the CPU load is around 5%.
Thanks to its complete digital operation the Audio Analyser offers features previous unavailable
from analog Analysers. These features include freely adjustable attack and release time, a
display configurable in many ways, different filters and special display modes. Because of the
hi-quality AD-conversion the ADI-96 PRO offers its Audio Analyser will precisely show
levels down to -120 dB.
Please note that the ADI-96 PRO will even in Audio Analyser mode operate as high
G
end Mic/Line AD-converter! But the functions provided by the 'Dual Mono A/D' software
(Low Cut, Delay, Expander, De-esser, NLC, ALC) are not available in Analyser mode.
11.2 Hotkeys
Some functions are directly accessible using predefined shortcuts:
Left
Right
L+R (Mono)
Freeze
RMS/Peak Level
Furthermore there's direct access to the following menu entries:
Help - Contents
Analyser Settings
The keys F5 to F8 offer a fast switch function between four different setups. The setups can be
changed anytime, as they consist of the four (supplied) files fastkey5.a96 to fastkey8.a96.
Load the according setup using the menu's entry File/Open Setup File, change the settings to
your needs. Then store the settings using Save Setup File, but don't change the name! Those
four files must reside in the same directory as the main program adipro.exe!
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L
R
M
space
D
F1
F2
User's Guide ADI-96 PRO © RME