To determine whether the audio cable needs to be replaced, a comprehensive assessment can be made from four dimensions: signal transmission quality, physical appearance, user experience and safety. The following are the specific judgment methods and reference standards:
1. Abnormal signal transmission: Sound quality and connection failure
The sound quality has deteriorated significantly
There is noise, current sound or distortion
Performance: During playback, there is a “sizzling” or “buzzing” sound, or the sound is muffled or distorted (commonly seen in 3.5mm headphone cables and RCA audio cables).
Cause: Internal wire breakage, shielding layer damage or interface oxidation, resulting in electromagnetic interference or unstable signal transmission.
When a mobile phone is connected to headphones and the noise changes when the plug is turned, it might be due to loose solder joints of the plug or a broken wire inside the cable.
Missing channels or unbalanced volume
Performance: Only one earphone/speaker produces sound, or there is a significant difference in volume between the left and right channels (such as one side being louder and the other softer).
Cause: A certain core wire of the cable is broken (such as the left/right channel wire of the TRS cable), or the interface contact is poor (such as oxidation of the 3.5mm plug).
2. Unstable connection or frequent disconnections
After the audio cable is inserted into the device, the Angle of the plug needs to be adjusted repeatedly for it to work normally, or it may suddenly fall silent during use (such as frequent disconnections when an external speaker is connected to a laptop).
Reason: The plug and interface are worn and loose, and the internal wires of the cable are loosely connected (such as the pins of the Shannon head of the XLR cable being bent).
Ii. Physical appearance damage: Directly threatens safety
The outer sheath of the wire is damaged
The insulation layer is cracked and the wires are exposed
Check the surface of the wire for any cracks, cuts or worn copper exposure (especially at frequently bent areas, such as near the headphone cable plug).
Risk: Exposed wires may cause short circuits and leakage, and may lead to electric shock when in contact with the human body (especially in a humid environment).
The wire is bulging or deformed
When the internal wires break and get knotted, or the shielding layer gets damp and expands, local bulges occur (such as the outer skin of an HDMI cable bulging).
Note: The strength of the wire at the bulging area decreases and it may break further.
2. The interface is aged or damaged
The metal contacts oxidize and rust
Green copper rust or black oxide appeared on the surface of interfaces such as RCA lotus heads and 3.5mm plugs, resulting in poor contact (Figure 1).
Treatment: Mild oxidation can be cleaned. In severe cases, the wire needs to be replaced.
The plug/socket is loose and the pins are bent
The pins of the XLR card holder and the 6.35mm instrument plug are skewed, or the HDMI interface card buckle is broken and cannot be fixed (Figure 2).
Risk: Forced insertion may damage the device interface and even cause the cable to get stuck inside the interface and be difficult to pull out.
3. Wire hardening or embrittlement
The rubber or PVC outer skin loses its elasticity and becomes stiff and brittle (commonly seen in wires that are exposed to the sun for a long time or in high-temperature environments).
Example: The outer sheath of the old-fashioned speaker cable cracks easily upon touch, and the copper wire inside is exposed.
Iii. Reduced user experience: Affecting normal functions
1. Signal attenuation or delay is obvious
When transmitted over long lines, the sound quality is blurred and the dynamics are weakened
Unshielded audio cables longer than 10 meters (such as ordinary 3.5mm extension cables) may cause high-frequency signal loss due to increased impedance, making the sound “muffled”.
The HDMI audio cable shows picture lag and audio and video are out of sync
Insufficient bandwidth of the cable (such as transmitting 4K 60Hz audio with HDMI 1.4 cable), or aging of the internal conductor leads to unstable data transmission.
2. Inconvenience or potential hazards in use
The wires are tangled and knotted and cannot be untied, or they are still frequently stepped on or pulled after being straightened (such as when the stage wires are severely worn).
Suggestion: Even if it can be used temporarily, frequent physical damage will accelerate the aging of the wire and it needs to be replaced in advance.
Iv. Safety Assessment: Emergency situations where replacement is necessary
There is a risk of electric shock or fire
The wire gets very hot (especially in high-current scenarios, such as speaker wires), and it feels hot to the touch.
The reason is that the cross-sectional area of the wire is too small, the insulation layer ages, causing an increase in resistance, and the current overloads and generates heat at high volumes.
Risk: May ignite flammable materials around (such as carpets, paper).
Short circuit tripping occurs when the wire comes into contact with water or a damp environment (such as leakage of the speaker wire caused by splashing in the kitchen).
2. Beyond the service life
Ordinary audio cables (such as 3.5mm, RCA) : They can be used for 5 to 8 years in a home environment. However, if they are frequently bent or used outdoors, their lifespan will be shortened to 3 to 5 years.
Professional cables (such as XLR, HDMI) : For stage or commercial Settings, it is recommended to inspect and replace them every 2-3 years to prevent cable malfunctions from affecting performance or equipment safety.
V. Judgment Process and Suggestions
Preliminary investigation
Replacement method: Connect the same type of normal cable to the device and observe whether the fault disappears (distinguish whether it is a problem with the cable or the device).
Cleaning test: Wipe the interface with an alcohol swab, reinplug and unplug it, and observe if it returns to normal (suitable for mild oxidation or poor contact).
Decide whether to replace or not
Replacement is necessary: damaged outer skin with exposed wires, severely oxidized/broken interfaces, overheating and smoking, and complete loss of sound quality.
Suggested replacement: Frequent disconnection, deteriorated sound quality that is ineffective after cleaning, hardened cable or beyond its service life.
It can be temporarily not replaced: minor poor contact (such as occasional mono channel), and appearance wear without safety hazards (such as minor scratches).
Replacement principle
Give priority to choosing wires of the same specification or higher quality (such as oxygen-free copper material, thicker shielding layer) to avoid repeated failures caused by insufficient wire performance.
For professional equipment (such as mixing consoles and Musical Instruments), it is recommended to use original or certified cables to ensure impedance matching and anti-interference capability.