DLS Svenska AB A5, A2 Noise Problems, Speaker Polarity Check, CONSTANT WHINING NOISE Do this

	ULTIMATE A-series
Professional Tip:	Professional Tip:
NOISE PROBLEMS	SPEAKER POLARITY CHECK.

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 and Ultimate-cables are Quasi-balanced.

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:

Crimp connections

Purchase crimp connectors and crimping tool. Connectors are color coded.

1.Strip 1/4 inch (6 mm) of insulation from the wire.

2.Insert into connector

3.Crimp tightly

All speakers in a car audio system should be connected in phase (the same polarity). All spea- ker 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, double check the connections instead.

Professional Tip:

Securing wires

Use wire ties to bundle together when possible. (But never bundle speaker wires or signal cables together with power wires).

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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