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R&S
CMW-B400B/-B405A
a) Select the "Analog Meas" tab or "Digital Meas" tab.
b) Select the relevant generator softkey ("Analog Generator" or "Digital Genera-
c) Press "ON | OFF" and wait until the generator softkey indicates the "ON" state
7. Start the internal/external audio measurement(s).
To start an internal measurement, proceed as follows:
a) Select the tab of the measurement to be started ("Analog Meas" or "Digital
b) Select the measurement softkey ("Analog Meas" or "Digital Meas").
c) Press "ON | OFF" to start the measurement.
Parallel measurements
One audio board supports two audio application instances. And each instance provides
an analog generator, a digital generator, an analog measurement and a digital measure-
ment. So in total there are four audio generators and four audio measurements.You can
use all these resources in parallel, for example to test several DUTs in parallel or to
perform stereo tests.
If your test setup contains more than one acoustic coupling, it is recommended to use
only one coupling at a time, so that they do not interfer. That means, transmit an audio
signal only via one coupling at a time.
Example: If both the microphone and the speaker of a DUT are coupled to the test setup
acoustically, test the speaker path and the microphone path one after the other. Activate
the audio generator of only one path at a time.
If the audio board is equipped with a single speech codec, this codec can be used by the
first instance of the audio application. Each codec can be coupled to only one signaling
application at a time.
3.3 AF Filter Settings
The AF input path of the audio measurements provides the following configurable filter
stages which affect the AF results:
●
Lowpass filter with a cutoff frequency of 3 kHz, 4 kHz or 15 kHz
●
Highpass filter with a cutoff frequency of 6 Hz, 50 Hz or 300 Hz
You can use this filter stage to eliminate a possible DC component in the audio signal
that may cause measurement inaccuracies.
●
Weighting filter
The human ear is a nonlinear sensor. Its sensitivity depends on the frequency.
Weighting filters take this into account by deemphasizing very low and very high
frequency components to which the human ear is less sensitive.
User Manual 1176.8116.02 ─ 01
tor").
and the hour glass symbol has disappeared.
Meas").
The measurement results are displayed in the measurement tab.
General Description
AF Filter Settings
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