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3. INTERNAL FILTERS
3.1 Reference 100A
Reference 100A has an internal variable lowpass filter that can be switched in/out. It can be set from 50
up to 200 Hz. It also has an internal higpass filter that
can be set from 15 up to 200 Hz.
LOWPASS FILTER:
The lowpass filter is normally used together with a
subwoofer to remove higher frequencies over the
crossover setting. A normal filter setting is 80 - 100
Hz.
HIGHPASS FILTER:
The highpass filter can be used in one of two ways.
Either as a subsonic filter together with a subwoofer
to remove the lowest frequencies which often causes
a rumbling bass reproduction. A normal setting is 20
- 30 Hz.
The highpass filter can also be used together with a
front or rear stereo system to remove frequencies
below the crossover setting. In a system with a
separate subwoofer it´s common to limit the bass
reproduction to the front system. A normal setting is
between 80 - 120 Hz, but feel free to try other settings.
3.2 Reference 200A
Reference 200A has the same filter configuration as
the Reference 100, but it´s doubled as this is a four
channel amplifier.
Suitable filter settings at different connections is found
in the section with connection examples.
INTERNAL FILTERS, FAULT FINDING GUIDE
If problems occour during the installation, or later, this
guide might help you to find out whats´s wrong.
THE AMPLIFIER IS DED:
1. Check power lead, ground and remote connections
at the amplifier using a multi meter.
2. Check the battery terminal connections.
3. Check the power lead fuse or circuit breaker. If
fuse damage continues, inspect the power lead for
short circuits.
4. Check the amplifier protection fuses. Are these
broken change to new ones with the sama value.
If short circuiting continues, contact your local DLS
dealer. A fault may exist in the amplifier.
5. To start the amplifier requires a remote voltage of
9-15 volt. Check the voltage with a multi meter.
AMPLIFIER PROTECTION FUSE BLOWS A T LOW
VOLUME :
1. One or more speaker cables are shorted. Make an
insulation test with a multi meter. The cables must
not have a connection to earth.
4. FAULT FINDING GUIDE
THE AMPLIFIER TURNS OFF A FTER 10 - 30 MINUTES.
The amplifier is overheating due to inadequate ventilation. Check mounting position is free from
obstruction.
Do this:
1. Move the amplifier to a place with better ventil-
ation.
2. Install one or two fans to cool down the heatsink.
3.Overheating can also be caused by an impedance
load below the level permitted. Refer to the section
about speaker loads.
NO OUTPUT FROM ONE OR MORE SPEAKERS:
Check the following:
1. Balance control position.
2. Fader control position.
3. Speaker cable connections to both amplifier and
drivers.
4. Signal lead plugs and cables.
5. Change left and right signal lead plugs in the
amplifier to see if the problem moves to a different
speaker, the the lead has a fault. If the problem
remains, the speaker or amplifier are at fault.
4.1 NOISE PROBLEMS
WHINING NOISE V ARYING WITH ENGINE
REVOLUTIONS:
Do this:
1. Rewire the power supply (12 V) to source unit
direct from battery.
2. Rewire ground wire from source unit to clean
position on chassis.
3. Check all power connections to ensure that they
are clean and tight.
4. Check quality of system ground connection.
CONSTANT WHINING NOISE:
Do this:
1. Ensure that all equipment is grounded at the same
place.
2. Check quality of earth strap connection from battery
negative terminal to chassis.
3. Disconnect signal cables from amplifier to see if
noise disappears. If so the leads are picking up noise.
Test this by laying a new cable over the seats and
reconnecting to the amplifier. If the noise does not
return, re-route original cable away from source of
interference.
If noise remains regardless of cable position, try to
use so called Quasi-balanced signal cables. DLS
PRO-cables are Quasi-balanced.