The article will consider information about whether the black wire is plus or minus. If there are no special devices at hand, then how to determine the polarity of the wires. Consider the example of the radio, how to determine the polarity.
How to determine the polarity?
Instruments are not always indicated. How to determine the plus and minus on the wires? You can quickly find out if you have a multimeter. And if it is not there and urgently need to supply power or start a car? With incorrectly connected wires, a device or a power source can easily fail. Therefore, it is important to correctly determine the polarity.
Let us examine the example of connecting speakers to the radio. There is a quick and easy way to detect phasing to connect speakers. This requires a simple Chinese multimeter.
You need to turn on the music on the device so that the signal goes to the speakers. Set the smallest voltage value on the multimeter.
We disconnect the cable from the speaker and touch it with the pointer of the multimeter. On the red wire we attach "+", on the black "-". If the connection is correct, the value with a "-" sign will be displayed on the multimeter.
Conclusion
Here is such a simple way to help determine the correct phasing. On the radio, the polarity at the factory can be confused, especially in cases where the marking is not indicated. Then you have to independently determine where the minus and where the plus.
When you correctly determine the polarity, then the problem is solved! To facilitate the task, instructions from musical equipment will come to the rescue, where you can easily find the conclusions correctly from the diagram. If the wires are black and red, then black is usually a "-". In order to verify the correct connection, you can apply a weak signal to both channels. If there is no bass, then the connection is incorrect.
If you do not understand, the black wire is plus or minus, then it is better to contact specialists.