CLIOwin 6.5 PCI User's Manual - Audiomatica Srl

If you are novice in using CLIO or to impedance measurements in general use this mode;
also do not start measuring loudspeaker impedance immediately. Get a 22 to 100 Ohm
resistor, possibly 1% tolerance, and make your experience with something you can
expect the results you should get. Here are two examples both with Sinusoidal and MLS.
Before you press go, remember to set the Y scale to Ohm. We choose a 47 Ohm resistor.
The modulus should be very close to the resistor value (red curve) and phase, important
as well should be very close to 0; All this must happens in the entire frequency range.
Notice that Fig.13.3, which refers to MLS, extends low frequency limit to 1Hz while
Sinusoidal, Fig.13.2, stops at 10Hz which is the lowest possible. If you are not getting
similar results do not proceed with a loudspeaker impedance measurement. You would
only add problems we will see soon to a not working procedure. Even in internal mode
CLIO’s output level is left to the user. We set it at +10 here as resistors are, hopefully,
the most linear devices we can get. As we had very comfortable results lets proceed with
a Loudspeaker.
50.0
CLIO
180.0
50.0
CLIO
180.0
Ohm
Deg
Ohm
Deg
40.0 108.0
40.0 108.0
30.0 36.0
30.0 36.0
20.0 -36.0
20.0 -36.0
10.0 -108.0
10.0 -108.0
0.0 -180.0
10 Hz
100 1k 10k 20k
0.0 -180.0
1 Hz
10 100 1k
Figures 13.2 and 13.3
13.3.1 MEASURING IMPEDANCE OF LOUDSPEAKERS
We will start with a 5" woofer using Sinusoidal, our preferred choice, with the
following Settings.
Aside frequency range, which can be changed without side effects, those above are
problems free settings for impedance measurements. We will experiment a little,
pointing out difficulties that might arise. Lets start with output level, which is a sensitive
topic.
128 Chapter 13 - Measuring impedance and T&S parameters