NOISE PROBLEMS
WHINING NOISE VARYING
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.
5.
Install a Power Cap capacitor. This
can be helpful against most noise
problems.
CONSTANT WHINING
NOISE:
Do this:
1.
Ensure that all equipment has a
common ground point.
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 Quasibalanced.
SPEAKER POLARITY CHECK.
All speakers in a car audio system
should be con-nected in phase (the
same polarity). All speaker cones must
move in the same direction. Out of
phase speakers will cause a lack of
bass, and a poor stereo soundstage.
Checking polarity:
Hold the connection of the speaker
wire to the
terminal of a 1,5 Volt
flashlight battery. Tap the + wire on to
the + terminal of the battery, and
observe the movement of the cone. The
cone should move outwards when the
wire touches the battery, and inwards
when the battery is removed. If it is
the other way around, the
speaker has
been connected backwards and it must
be removed and connected correctly.
If your system also has a subwoofer
connected through a passive 6 or 12
dB crossover, try to connect this with
various polarity and judge what sounds
best. The phase shift in passive
crossovers sometimes makes it
necessary to change polarity.
+
-
+
-
Battery
1,5 Volt
NOTE!
Tweeters can not be tested this way, dou-
ble check the connections instead.
Professional Tip:
Professional Tip:
Professional Tip:
Installing in trunk
When installing the amplifier in the
trunk, run the power wires along the
same path as the other vehicle
wiring. Many cars have insulated
channels for wiring. you will have to
remove the door sill trim and the carpet.
Professional Tip:
Speaker and power wires
Do not run speaker and power wires next to each
other. Power wires can generate a ”siren” sound
in the speakers. Run speaker and power wires on
opposite sides of the car.
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