DK Digital CDB-600 Dokumentacja Pobierz pdf (Strona 42)

Chapter 10 FFT Spectrum Analyser. PRELIMINARY Release MSD Software Manual.

10 FFT Spectrum Analyser.

Most spectrum analysers used in sound engineering are based on analogue

filtering techniques. For many years this has been the only practical solution for

real-time analysers at a sensible size and cost. However, modern Digital Signal

Processing (DSP) used by the MSD Family have made it possible to implement

the complex FFT (Fast Fourier Transform) algorithm, which radically out

performs its analogue counterpart many times over. For example, the number

of frequency bands has been increased from the traditional 27 or 31, to a

massive 512, and the dynamic range to 80dB. These improvements make it

possible to analyse noise, distortion(IM) and frequency response in a far more

detailed and accurate way than ever before.

To enter the FFT Spectrum Analyser mode, select [FFT] key from the Main

Menu in Full Feature Mode or select the ‘FFT-Analyser’ from the start menu.

Frequency is indicated at the bottom of the screen from 48Hz to 20kHz, with

signal level indicated on the left hand side in 10dB intervals from -70dB to

+10dB.

10.1 Routing Audio to the Analyser Applications.

Both Spectrum Analysers (1/3 Octave and FFT) available in the MSD shares

the same destination in the Audio Matrix (#51 Spec). In that way when toggling

between the 1/3 Octave and the FFT analyser it is not needed to set-up the

Matrix more than once.

Please refer to section 5 'The Compact Audio Matrix' for information on how to

route signals in the Audio Matrix.

Page 38 of 64. PRELIMINARY Release

A Section of the Matrix Status Window

with CH 1 (PPM Bar #1) selected as

source for the Analyser Applications.

1 2 ... 37 38 39 40 41 42 43 44 45 46 47 ... 67 68

Brak uwag

DK Digital CDB-600 Dokumentacja Strona 42