Many people want to install a subwoofer in their car, but few are strong in electrical engineering. Therefore, before getting down to business, you should study the general principles of connecting this device, because incorrect connection will result in damage to the equipment.
In order to connect an active subwoofer to a car radio, it must be powered. Typically, power is supplied by a car battery. A subwoofer at low-frequency peaks can consume quite a lot of power, so at this moment it is often possible to observe a decrease in the brightness of the vehicle's lights on.
For safety and protection of the electrical system of cars from overload in this case, it is recommended to install a capacitor observing the polarity. In the circuit, it must stand in parallel with the subwoofer. Also, for fire safety purposes, they put protection against a short circuit: a 40A fuse is placed on the positive wire going from the battery to the subwoofer, at a distance of 40 cm from the battery terminal. After completing the above, you can proceed to connecting the subwoofer to the car radio.
Since the subwoofer is active in this case, it means that it has a built-in amplifier. Therefore, to connect an active subwoofer to a car radio, no additional external amplifiers are required. To connect it to the radio, there is an RCA interface (also known as "tulip").
If the car radio does not have a special output for connecting a subwoofer, then it will have to be connected to standard speaker outputs, but at the same time it is necessary to use a low-pass filter, in the region of 20-250Hz. This is done so that the subwoofer speaker reproduces only a certain frequency range, this has a positive effect on the sound quality, and the frequency response of the equipment is preserved.