CLIOwin 7 PCI User's Manual - Audiomatica
CLIOwin 7 PCI User's Manual - Audiomatica
CLIOwin 7 PCI User's Manual - Audiomatica
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9 FFT, RTA AND “LIVE” TRANSFER FUNCTION<br />
9.1 INTRODUCTION<br />
By selecting the FFT command from the main menu bar, it is possible to carry out Fourier<br />
analysis of the input signal to determine its frequency content using the Fast Fourier<br />
Transform (FFT).<br />
The ability to process two channels simultaneously, to select the appropriate sampling<br />
frequency and the possibility of triggering with respect to the generated signal make this<br />
control panel a flexible and valuable instrument. Finally, there is also a very useful facility<br />
to quickly and easily swap back and forth between the time and frequency domains.<br />
The FFT processed data coming from the two input channels can be displayed as<br />
narrowbands, 1/3 (or 1/6) octave bands (turning the instrument into what is<br />
generally called a real-time analyzer or RTA) or, referencing one to the other, as live<br />
transfer function (you may also use music as stimulus).<br />
What you get are three different instruments in one.<br />
9.2 NARROWBAND FFT ANALYZER<br />
Fig. 9.1 The FFT control panel<br />
Pressing the FFT button you select the narrowband FFT analyzer. Fig. 9.1 shows the<br />
FFTcontrol panel (while processing a sinusoidal input signal). The narrowband FFT<br />
analyzer is a general purpose instrument that can be applied to the frequency and time<br />
analysis of any kind of electroacoustical signal.<br />
There now follows a description of the FFT control panel toolbar and settings.<br />
For a detailed description of the graphical display (common also to other measurement<br />
control panels) and its capabilities please refer to Chapter 6. For a description of the<br />
available shortcuts please refer to section 4.5.2.<br />
Chapter 9 - FFT 93