Operation Manual
11. Operation and performance
30
D SERIES Lake Operation Manual rev 3.0.4
11. Operation and performance
30
D SERIES Lake Operation Manual rev 3.0.3
11.6. LoadPilot Load Monitoring
11.6.1. Introduction
LoadPilot is a feature in D Series ampliers that can continually monitor the integrity of loudspeakers and cables
connected to the outputs to ensure that they are functioning properly and free from major anomalies or faults.
By implementing LoadPilot, systems incorporating D Series ampliers can be certied in compliance with voice
evacuation standards such as EN54–16 and NFPA72.
LoadPilot functions by automatically superimposing low–level pilot tones on the input signal (if any present) to the
amplier. One tone is below the range of human hearing (approximately 10–20 Hz) and the other above (24 kHz),
so the activity of LoadPilot is inaudible regardless of whether the system is currently reproducing program content.
High–resolution current sensing on the outputs can calculate the impedance of the load at the frequency of the
tones. Hence a stable measurement of the impedance of the load can be obtained and potential anomalies or
faults can be detected that would indicate impaired loudspeaker function or total inoperability due to failure of the
loudspeaker or faults in connected wiring. The superimposition of pilot tones and analysis is interleaved across the
amplier’s output channels with a maximum total cycle time of around 20 seconds.
LoadPilot is implemented and congured in the CAFÉ software. Monitoring status and fault indication are displayed
on the front panel and both in CAFÉ and Lake Controller.
LoadPilot may be congured with the automatic calibration or through a manual advanced mode, depending on
monitoring requirements and characteristics of the connected loudspeaker loads.
11.6.2. Automatic calibration
11.6.2.1. Functional description
Automatic calibration is suitable for the following applications and requirements for error detection:
• If one or two low–impedance loudspeakers are connected; if two in parallel is default, it will warn if one is
missing.
• If there are one or two “spurs” with 70V loudspeakers connected; if two in parallel is default, it will warn if one
is missing.
• If there is a short circuit in the load.
• If there is an open circuit (all loudspeakers missing).
• For passive 2– and 3–way loudspeakers, if one or two LF drivers are connected and working; if two in parallel
is default, it will warn if one is missing.
• For some passive 2–way designs, if one HF driver is disconnected. (However, with some loudspeakers the
HF impedance is dominated by a passive component i.e. crossover lter and the anomaly will not be detected.)
NOTE: LoadPilot is enabled only when the amplier is On. It does not function while the amplier is in
Standby.