Channel setup
7.7 System check/LM
7.7.1 System check
System check is a powerful and convenient tool to check the
condition of a complete d&b sound reinforcement system driven by
d&b amplifiers. It is preferably used in conjunction with the d&b
Remote network and the R1 software.
However, for smaller systems or single cabinets, System check can
also be accessed and executed locally. For both, System check
and calibration, audible sine wave signals are used.
System check utilizes the amplifier's capability to measure the
impedance (Z) connected to its outputs using an audible sine wave
signal created by the DSP section of its controller.
Selecting «System check» opens the corresponding subscreen.
System check menu
The System check menu provides two buttons to start either a
«System calibration» or a «System check» run.
In addition, a table is provided indicating the progress («Status»)
and the results (Z values) for both the calibration («Calib.:») and
the check («Check:») runs.
The column header of the table for the Z values changes according
to the connected loudspeaker cabinet, provided the respective
loudspeaker setup is loaded.
Status
Brief indication of the current status of the calibration or
check process. In case of an error the status is indicated
in red.
LF The calibration and check results for the LF section.
LF®) The calibration and check results for the rear LF driver
of an actively driven cardioid subwoofer, such as the
KSL-SUB.
MF The calibration and check results for the MF section of
applicable cabinets.
HF The calibration and check results for the HF section.
System check procedure
The typical procedure using System check is as follows:
1. When the system is fully set up, check and verify all
connections.
2. Mute all amplifier channels.
↳
The correct wiring of the system can now be tested by
listening to each channel separately using an appropriate
audio program and the MUTE switches - preferably
controlled by R1.
3. Unmute all channels, if required.
4. Execute a System calibration.
↳
The calibration process identifies the actual load
impedances for each channel by playing different
calibration noises. The result will be stored as a reference
and used to calculate the upper and lower limits for the
tolerance band.
To verify the correct connection of cabinets and amplifiers,
the calibration result can be compared with the typical
impedance values for d&b loudspeakers.
For this purpose, please refer to the d&b R1 Help (Þ within
R1 press F1).
d&b D40 Reference manual 1.5 en48