User`s manual

MSD100 Series - User’s Manual

Figure 4-6 shows the FFT Spectrum Analyser display on

the MSD100/SA.

To select the FFT Spectrum Analyser mode:

1 Press [FFT]. The FFT screen is displayed, as shown

in Figure 4-6.

Frequency indicators from 44 Hz to 20.000 Hz appear

at the bottom of the screen. Level indicators, in 10dB

increments from –70 to +10dBu appear on the left

side.

2 Press [LEFT] or [RIGHT] to select the left or right

input signal for FFT analysis. A small black square

indicates the input selected. It toggles on or off as the

key is pressed.

☞

Note: To analyse a mono signal, press both

[LEFT] and [RIGHT] keys.

3 To return to the main menu, press [EXIT].

4.11.2 1/3-OCTAVE SPECTRUM ANALYSER

The

/3-octave spectrum analyser provides real-time fre-

quency analysis through a bank of filters, each with a re-

lative bandwidth of 1/3 octave. This instrument provides

a 31-bar display for numerical and graphical visualisation

of the signal energy present at different frequencies

across the audio range from 20Hz to 16kHz.

The 1/3-octave spectrum analyser has many applications,

including acoustical measurements in control rooms and

PA system. The relative bandwidth filters are ideally suit-

ed for applications where the signal being measured must

also be heard, since the ear perceives frequencies loga-

rithmically.

FIGURE 4-8. FFT Spectrum Analyser