BM15A Owner’s Manual - Issue 2 Page 4
November 1997
The left indicator is a 'true-clip' indicator and lights if the low frequency amplifier clips, or runs
into overload. It is acceptable to run the system with this lighting occasionally on peaks, but
avoid running the system with it lighting most of the time
Running-In
The drivers in your BM15A must be run-in before optimum performance is achieved. Avoid
using the system at high levels for the first 24 hours of operation. Full run-in is usually
achieved after about one week of normal operation.
Protection
The BM15A has a comprehensive electronic protection system. Thermal overload or dc
voltage on the outputs will cause the system to engage. This will disconnect the drive units
from the amplifiers and change the power LED to it’s red/fault condition. In addition the HF
amplifier has an optical limiter in circuit which prevents excessive long term power reaching
the tweeter whilst allowing transients to pass uncompressed.
Troubleshooting
If the speaker stops working and the power LED turns red (fault condition) switch the mains
power off and leave it for a moment. If the unit fails to operate again when you switch back on
the fault may be due to overheating, switch off again and allow it to fully cool down before
powering up. Ensure the heatsink is clear of obstruction and has free air circulation around it.
If however the fault condition persists the unit should be inspected by qualified personnel
(your DA dealer).
If the speaker stops working and no LED’s are alight then the mains fuse on the back panel
should be checked and replaced if necessary. If this does not rectify the problem the unit
should be inspected by qualified personnel (your DA dealer).
Care
Components of the highest quality are used in the BM15A. and should give a long trouble free
life. Here are a few hints to help them on their way.
Avoid running the system into more than very brief clipping or distortion. When an amplifier
clips it can send potentially damaging d.c. components to the drive units. They may not fail at
once but prolonged exposure to this will result in eventual failure.
Avoid unplugging or switching off any equipment that is connected to the monitor system
without first turning off the BM15A. Large voltage spikes are often generated when equipment
is switched off which will be amplified to a potentially damaging level.
Do not touch the drive units. The tweeter especially uses a very fine fabric diaphragm which
is easily damaged.
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