User manual

FFT Analyzer
AM700 Audio Measurement Set User Manual
4-91
waves at several frequencies. From the received multitone signal, Multitone
measurements produce level versus frequency or distortion plus noise graphs.
Multitone detection and measurements are made using FFT techniques. In order to
correctly detect and analyze multitone signals the FFT size should be greater than or
equal to the record size used for generating multitone signals.
Multitone Measurement mode maintains multitone descriptions in the rom:/mtone
directory and nvram:/mtone directory. You can choose any multitone from this file
for detection and subsequent analysis. When the AM700 generator is used to
generate the multitone signal, that signal can be selected as the one that will also be
detected by the AM700 (see Figure 4-42).
Figure 4-42: Generator Waveform Control setup for multitone detection
Multitone
Detection