1、 Car audio wiring

(1) The lower the resistance of the car audio wire, the less power consumed on the wire, and the greater the efficiency of the system

(2) The lower the resistance of the wire, the greater the damping coefficient. The greater the damping coefficient, the greater the residual vibration of the speaker.  

(3) The larger the cross-sectional area (thicker) of the wire, the smaller the resistance, and the greater the tolerance current value of the wire, the greater the allowable output power. However, the wire of the tweeter in the speaker should not be too thick. Because there is a "skin collecting phenomenon" in electric current, that is, electric current preferentially flows through the outermost ring of the wire. The amount of current in high-frequency signals is very small. If the wire is too thick, the current signal only flows on the surface of the wire, resulting in signal loss. Choosing too thick wire is a waste and greatly increases the difficulty of installation. Various factors should be considered in the selection of wire materials, and specific analysis should be made.

(4) No matter what wire is too short, it should be avoided to reuse it after connection. The connection point is often the root cause of future failures.

(5) Selection of power supply fuse. The closer the fuse box of the main power supply is to the vehicle battery, the better. The fuse value can be determined by the following formula: fuse value=(x2 after the total rated power of each power amplifier in the system)/average value of the vehicle power supply voltage.

2、 Audio signal line

(1) Here, it mainly refers to the RCA output signal line, which is a coaxial signal line with a shielding layer. It is only used for signal transmission and does not transmit power.  

(2) Wrap insulating tape around the audio signal line connector to ensure insulation. Noise can be generated when the joint is in contact with the vehicle body.

(3) Keep the audio signal line as short as possible. The longer the audio signal, the more susceptible it is to interference from noise signals. Note: If the length of the audio signal line cannot be shortened, the overlength portion should be folded instead of rolled up. The length specifications generally include 6m, 5m, 3m, 2m, 1m, 0.5m, etc., of which 5m is the most commonly used.  

(4) The audio signal line should be routed at least 20 cm away from the power cord of the trip computer unit and power amplifier. If the wiring is too close, the audio signal line can pick up induced noise. It is best to separate the audio signal cable and power cable on both sides of the driver's and passenger's seats. Note that when wiring near power lines and microcomputer units, the audio signal lines must be more than 20 cm away from them. If the audio signal lines and power lines need to cross each other, it is recommended that they intersect at 90 degrees.

3、 Power cord

(1) The power cord includes a main power cord and a sub power cord. If the system is simple, just one main power cord is enough. If the system is complex, it is necessary to separate power cords and splitters. The length and structure of the power cords from the splitter to each device should be the same.

(2) When the power line is bridged, there will be a potential difference between the various power amplifiers, which will cause AC noise and seriously damage the sound quality. When the host is powered directly from the power supply, noise is reduced and sound quality is improved.

(3) The main power line should be protected by a fuse tube that should be as close to the power source as possible. The wire splitter has a fuse tube on it, ensuring the safety of the power cord. The current capacity value of the power line should be equal to or greater than the value of the fuse tube.  

(4) There are strict regulations on the size of wire specifications and the power they withstand. The wire specifications are nominal in AWG or g.

(5) Thoroughly remove the dirt from the power (battery) connector and tighten the connector. If the power connector is dirty or not tightened, there will be contact resistance at the connector. The presence of contact resistance can lead to AC noise, which seriously damages the sound quality. Use sandpaper and a fine file to remove dirt from the joint.  

(6) When routing wires within the vehicle powertrain, avoid routing wires near generators and ignition devices, as generator and ignition noise can radiate into the power cord. When replacing the factory installed spark plug cable with a high-performance type, ignition interference is stronger, and ignition noise is more likely to occur.  

(7) The principle followed by the power cable and audio cable on the interior of the vehicle body is consistent.

4、 Horn wire

(1) Speakers with different powers should choose different numbers of speaker lines.  

(2) Attention should be paid to the protection of the wire entering the door, and the impact of door closing and window lifting on the wire should be considered.  

(3) The connection between the speaker cable and the speaker is preferably welded.  

(4) The speaker wires are double stranded. Generally, the colors of two strands of wire are different or have different markings, which represent the different polarities of the two strands, namely, the+and - poles. When wiring, attention should be paid to the unity of the polarity of each connection point.  

5、 Ground wire

(1) Ground wires are often overlooked in wiring, but in fact, their role in the system is as important as power lines. Many people are accustomed to using a wire that is much thinner than the power cord as a ground wire. Little did it know that this would affect the performance of its power. "Because thin wires can block current and create unnecessary impedance, it is important to choose a ground wire as thick as the power wire as possible.".

(2) Grounding wire method. Remove the paint from the vehicle body grounding point with sandpaper and fix the grounding wire tightly. If paint remains between the vehicle body and the ground terminal, contact resistance will occur at the ground point. Similar to dirty power connections, contact resistance can cause AC noise, which can seriously damage the sound quality.  

(3) Concentrate the grounding of each module in the audio system in one place. If they are not grounded in one place, the potential difference between the various components of the audio system can lead to noise generation. Note: The host and power amplifier should be grounded separately. In complex systems, it is recommended to use a wire splitter. Each wire splitter is used to synthesize a total ground wire for grounding. There is no fuse on the wire splitter of the ground wire (there is a fuse on the power supply wire splitter).  

(4) Do not approach the trip computer wiring. Please remember that when the host ground point is close to the ground point or fixed point of the trip computer, it will generate trip computer noise.  

(5) The grounding point should be as close as possible to the ground wire output point, making the ground wire as short as possible. An excessively long ground wire will greatly increase the likelihood of noise generation and increase resistance.

6、 Why should car stereos be insured? This is related to the electrical characteristics of automobiles: single wire system, low voltage, and high current.  

1. If no fuse is installed or the fuse specification is too large, there is a risk of spontaneous ignition of the power cord.

2. All power cords related to the audio system must be equipped with fuses of corresponding specifications

3. The correct fuse must be selected for each power cord.

4. The fuse must be removable within 60 seconds.

5. Any audio system power cord connected to the positive pole of the battery must have a fuse installed within 40 centimeters of passing through the first firewall.

6. When adding a battery, if the length of the power cord between the positive electrodes of the two batteries is less than 40 centimeters, it is not necessary to install a fuse. If it exceeds the length, it is necessary to install a fuse.

7. No matter how the wire diameter of the power cord changes, the specification of the fuse must comply with the maximum current withstand range of this power cord. If a thick wire is connected to several thin wires through the power cord, a fuse must be installed at the connection position between the thick wire diameter and the thin wire.

8. All outgoing lines on the positive power distribution box must be separately fused, and the negative pole does not need to be additionally fused.  

9. When using two parallel power lines, both lines must be fused

10. Be sure to pay attention to the grounding wire. If the diameter of the grounding wire is smaller than the positive wire, the corresponding fuse specification of the positive power line should be determined based on the diameter of the grounding wire.

7、 Finally, it is also emphasized that all electrical connection points must be stable during construction

1. The wire connectors of all terminals must be protected from short circuits (the positive electrode of the battery or the metal surface of other wiring connectors should not be touched with your fingers).  

2. Appropriate protective measures must be taken to prevent damage to the wiring of the audio system.  

3. Such as sharp metal edges (high temperature, humidity, moving and pressing, dangerous locations, vibration induced wear).  

4. All power cords passing through metal plates must be protected with metal eyelets or sleeves or sleeves.

5. The wiring of all audio systems in the vehicle should be properly hidden.