User`s manual

If you are a 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 gain experience with something
which you should already know the expected results of. Here are two examples
both with Sinusoidal and MLS. Before you press go, remember to set the Y scale to
Ohm. For this example we chose a 47 Ohm resistor. The modulus should be very
close to the resistor value (red curve) and equally important, the shown phase
should be very close to 0; these results should cover 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.
To do so would only add problems later by using an inaccurate working procedure,
as we will soon see. Even in internal mode CLIO’s output level is left to the user. We
set it at +10dBu here as resistors are, hopefully, the most linear devices we can
get. Since we had very comfortable results lets proceed with a Loudspeaker.
Audiomatic a Srl Sinusoidal 03/07/2001 10 .11.25
CH A Ohm Unsmoothed Stepped Delay [ms]: 0.000 Dist Rise [dB]: 30.00 File: thd1.sin
10 100 1k 10k 20k10 Hz
50.0
Ohm
180.0
Deg
40.0 108.0
30.0 36.0
20.0 -36.0
10.0 -108.0
0.0 -180.0
CL IO
Audiomatica Srl MLS - Frequency Response 03/07/2001 10.29.25
CH A Ohm Unsmoothed 3.2kHz 65K Rectangular File: impulse.mls
10 100 1k1 Hz
50.0
Ohm
180.0
Deg
40.0 108.0
30.0 36.0
20.0 -36.0
10.0 -108.0
0.0 -180.0
CL IO
Figures 13.2 and 13.3
182 13 MEASURING IMPEDANCE AND T&S PARAMETERS