Soft dB Opus Suite SLM & 3Vib Module - Manual (Page 24)

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6.1.5 SLM Dynamic Range
The dynamic range of the SLM input is around 94 dB. Two ranges are available (Low or High) 2 . The
table below provides examples of the dynamic ranges for given sensitivities of 40 and 50 mV/Pa.
Microphone Sensitivity 40 mV/Pa
50 mV/Pa
Low Range 27 to 121 dB(A)
25 to 119 dB(A)
High Range 39 to 132 dB(A)
37 to 130 dB(A)
6.1.6 SLM FFT High Pass Filter
Several frequency bandwidths are available with the FFT spectrum:
Bandwidth FFT Lines
Frequency Resolution
20 kHz 854
23.4 Hz
10 kHz 854
11.7 Hz
5 kHz 854
5.85 Hz
3.33 kHz 854
3.90 Hz
2 kHz 854
2.34 Hz
1 kHz 854
1.17 Hz
An electronic high-pass filter set at 0.9 Hz is applied on the input to block any DC. However, another
filter can be applied to the FFT Spectrum to match the 1/3 octave spectrum frequency span, which is
6.3 Hz to 20 kHz.
The high pass filter cut-off frequency can be lowered but the global level resulting from the sum of
the FFT lines may be different than the SLM global levels (LS, LF, LI, Leq and SEL) and their associated
1/3 Octave Spectrum.
2
Both low and high range should be available on the SLM input of a Concerto unit. Other hardware (such as
Alto-6ch and Itrack) may only have the low range available.