CLIOwin 7 PCI User's Manual - Audiomatica

L 1kHz
L 10kHz
Inductance at 1kHz
Inductance at 10kHz
13.7.3 T&S STEP BY STEP
Getting T&S requires two impedance measurements. As we will use both methods we
need three, the first relative to the driver in free air, the second to the driver with a known
mass (Delta Mass) added to the cone, the third to the driver loaded with a known volume
(Delta Compliance). Fig.13.20 shows the results of the three measurements, overlaid
in one single graphic.
50.0
CLIO
180.0
Ohm
Deg
40.0 108.0
30.0 36.0
20.0 -36.0
10.0 -108.0
0.0 -180.0
10 100 1k Hz
10k 20k
Figure 13.20
The black curve refers to free air, the red to delta mass, the green to delta compliance.
As you can see adding a mass results in lowering Fs while loading the cone with a closed
volume will increase Fs. Always check this is the case to avoid errors in the post
processing routine. As deriving T&S parameters can be performed at any subsequent
time after the impedance measurements has been taken, we suggest you save them
with meaningful names as well as using the Notes Dialog to store the measuring
conditions as mass weight and/or volume. The last step before pressing Go in the T&S
dialog is to measure both the voice coil DC resistance and the effective cone diameter
in millimeters. In this example they are 6.41 Ohm and 133mm. Finally we select File
Data as the data origin and pressing Go we get the following prompt Dialog
170 Chapter 13 - Measuring impedance and T&S parameters