CLIOwin 6.5 PCI User's Manual - Audiomatica Srl

12.5 MEASURING AND REPRESENTING LOUDSPEAKER POLAR DATA
Suppose now we want to measure and give a graphical representation of the polar
response of the same speaker analyzed in 12.4. We need to measure its anechoic
frequency response, at various angles, with MLS and save the files following the rules
given in 12.3.2. We will use a turntable (Outline ET/ST), under CLIOwin's control, and
the automation possible within the MLS control panel.
12.5.1 PREPARING THE MLS CONTROL PANEL
For this test we would like to measure the speaker from -60° to +60° (in intervals of
5°) relative to its front baffle.
The MLS measurement should be set in a particular way in order to automatically
acquire the responses at various horizontal angles. To do this we will use the
autosave function, the loop mode and the link to the turntable control.
Let's start from setting the autosave function. Pressing Alt-F2 we recall the Autosave
Setting dialog (fig.12.10); here we input the desired filename ('rcf deg'), start (-60)
increment (5) and total (25) values.
Figure 12.10
The MLS menu is now ready to start taking measurements; we only need to properly
set the turntable and its control.
12.5.2 PREPARING THE TURNTABLE
We consider that the Outline turntable is properly connected to your PC (refer to 5.5.2
to have details). To prepare for this measurement session you need to:
1) Manually set the front selector labeled 'Deg Step' to 5°.
2) Rotate counterclockwise the turntable until you reach the desired start position: as
we want to start from -60° position it at 300°.
3) Recall the turntable control dialog (Fig.12.9), set Resolution at 5°, Speed at 0.75 RPM
and press Link To Measurement
Chapter 12 - Waterfall 123