User guide Owner's manual

User manual for the ZEN 3-channel X-LMS controller Soft dB inc.
Secondary control path parameters (filters CxEy)
The parameters for the secondary path filters are: the number of coefficients of the CxEy
filters, the adaptive step size of the identification LMS and amplitude of the white noise
used during the identification process.
The CxEy filters are used during the control phase to filter the reference signals before
X-LMS optimization.
Control Parameters
The control parameters are: the number of coefficients for the Wx control filters, the
adaptive step size of the X-LMS and the white noise amplitude (between 0 and 1.0) used
to avoid control filter saturation (see the section 3.2.3).
We suggest starting with a very low adaptative step size for X-LMS (near 0.01) and a
white noise amplitude of zero. White noise amplitude should only be increased if a
saturation problem occurs.
Input gain and input selection (microphone/direct)
Input gain is adjustable between 0 dB and 54 dB. The dBFS meter (dB referenced to the
16-bit dynamic) and the Selected Input control allows for monitoring the current level on
each input and making adequate adjustments to the input gain.
The input type can be either direct input or microphone. Each input-type selection for
each ZEN controller input can be done independently. The microphone input includes a
16 Hz high pass filter and can drive an electret type microphone (10 kΩ load). For the
microphone input, the input dynamic range is ±2 Volts at 0 dB. The direct input dynamic
range is ±20 Volts at 0 dB.
Output gain
The output gain can be set between 0 dB and –54 dB. The addition of an attenuator on a
specific output can be useful for increasing the control filter dynamic if an external
volume is not available.
DC filter set-up (applied on all inputs)
All ZEN controller inputs include a digital DC filter with an adjustable cut-off frequency.
We suggest avoiding using a very low cut-off frequency because of the length of the
ZEN User Manual p. 25