In our daily lives, each of us has used headphones or speakers to listen to a lot of songs. Do you understand what the cables are and the differences between them?

Today, I will introduce you to some common audio cables. I hope you will have a new understanding of the cable of the audio equipment.

PS: You can directly view the chart of plug and interface of common audio cables at the end of the article.

First of all, I will give you the two major classifications of audio signal cables. According to the type of transmission signal, the audio cable can be divided into analog audio cable and digital audio cable. According to the wiring method, it can be divided into balanced cable and unbalanced cable.

Analog audio cable and digital audio cable

Analog audio cable: analog audio is the technology of transmitting, recording, playing back, and processing sound signals in an analog state. Similar to the microphone game in daily life, analog audio cable transmission is intuitive and easy to implement but is relatively distorted and unstable.

Common analog audio cables are TRS cable, XLR XLR XLR cables, RCA cable, etc...

Digital audio cable: digital audio is the technology of recording, storing, editing, compressing, or playing sound through digital means. The transmission of digital audio signals need to sample the analog signal first, followed by the quantization of the sampled values into different levels, and then the quantization of different levels of encoding, a level corresponds to a set of binary digits, and finally get a series of binary digits, completing the conversion of analog signals to digital signals. Thus, the higher the sampling rate and quantization level, the higher the accuracy of the analog-to-digital conversion, the stronger the ability to restore the signal.

Common digital audio cables are AES/EBU physical cable, S/PDIF cable, coaxial cable, and optical cable.

Balanced audio cable and unbalanced audio cable

A balanced transmission cable uses two channels to transmit signals with the same voltage and opposite phase. The receiving device subtracts these two sets of signals, and the interfering signals are canceled out, resulting in a high-quality analog signal.

Common balanced transmission audio cables are TRS cable, XLR XLR XLR cables, etc...

working of balanced audio cable

An unbalanced transmission cable consists of a signal line responsible for transmitting the signal and a combination of ground wire. In the process of signal transmission, the wire will be subject to external interference through the secondary amplification of the microphone or amplifier. As the anti-noise ability is relatively weak, so it is easy to output a section with noise sound.

Commonly unbalanced transmission audio cables are the TS cable and RCA cable.

working of unbalanced audio cable

Common audio cables introduction

TRS cable: TRS is explained as Tip, Ring, Sleeve. It’s a large three-core cable with three segments separated by contacts, usually using a 6.35 mm diameter plug. The advantage is that it is resistant to wear and tear and suitable for repeated plugging and unplugging. Because of the relatively high production cost, it is generally used in high-grade professional audio equipment.

1/8TRS cable (small three-core, 3.5mm cable): It is the most important sound card cable we currently see. The vast majority of consumer sound cards (including on-board sound cards) are using this type of cable, such as car AUX cable or audio equipment headphone cable.

TS cable (large two-core): It has two separated contacts, transmitting mono signals, most commonly used in the guitar, bass, keyboard, and other musical instrument wires.

XLR cable: It consists of a three-pin plug (male port) and a locking device (female port). Due to the use of locking devices, the XLR connection is quite secure, generally used for microphone connection sound card or speaker connection.

RCA cable: Each RCA cable is responsible for transmitting one channel of the audio signal, so a pair of cables are required to transmit stereo signals. For a multi-channel system, the actual number of channels with the same number of cables. We may see RCA on desktop speakers in daily life.

Note: Stereo RCA audio cable, the right channel will generally be marked in red, the left channel is marked in blue or white.

AES/EBU cable: the type of digital audio cable jointly designed by the American Association of Recorders and the European Broadcasting Union. It is often found on professional AD/DA decoders or some high-end monitor speakers. Input/output interfaces of AES/EBU cable can transmit two channels of PCM (digital audio signal), and the channels are automatically timed and self-synchronized.

Note: although ordinary XLR (Canon port) is almost identical in appearance to the AES/EBU cable, it is not recommended to transmit digital signals because of the need for the impedance of 100 ohms AES/EBU digital Canon cable to connect the front and rear devices.

S/PDIF cable (Sony and Philips digital cable): It is a civilian digital audio cable protocol jointly developed by Sony and Philips. Each individual cable can transmit two channels of PCM digital audio signals, so it will not degrade the audio quality as the analog signal is interfered with.

Note: Coaxial digital cable and fiber optic cable are in the category of S/PDIF cable.

Digital Coaxial cable: It is a digital audio cable belonging to the S/PDIF protocol, generally divided into RCA coaxial cable and BNC coaxial cable, often found in digital mixers, jukeboxes, TV, and broadcast equipment.

(SPDIF-RCA coaxial interface and plug)

(BNC coaxial interface and plug)

Fiber optic cable (TOSLINK/Toshiba Link): It transmits digital signals in the form of optical pulses, and is often identified as OPTICAL. It also uses the S/PDIF protocol, characterized by high bandwidth and low signal attenuation, and is used for conventional sound cards, home set-top boxes, or digital TVs, connecting DVD players and AV amplifiers, supporting PCM digital audio signals, Dolby and DTS audio signals. In addition, the optical interface can also be used ADAT protocol.

Note: It must not be bent in use, otherwise it will cut off the transmission of optical signals in the same way interrupted.

MIDI cable: It is usually used to connect recording equipment and computer. The MIDI cable transmits signals, intensity, sustain pedals, and other information to the computer for applications such as arranging, recording, and writing scenarios.

Common audio cable chart