What Types of Audio Interfaces Are There?

The audio interface is the key part of transmitting signals between audio devices, which determines the quality and transmission method of audio signals. It usually includes two types: analog and digital. If it is further subdivided, there are several different types, all of which are relatively common.

I. Analog audio interface

1. RCA interface: RCA is the abbreviation of Radio Corporation of American, also known as AV terminal or lotus head, usually used to transmit analog audio and video signals. It uses coaxial transmission signal method, the middle axis is used to transmit signals, as the contact layer around the outer edge is used for grounding. RCA interface can be commonly found in home audio and video equipment.

2. TS and TRS interface: TS (large two-core plug) is mainly used for mono signal transmission, such as electric guitar cable. TRS (large three-core plug) can be used to transmit stereo signals or balanced signals, whose common usages including the equipments like headphones and microphones.

3. XLR interface: XLR interface, also known as Canon head, is a high-end audio interface, mainly used in professional audio equipment such as microphones and speakers. It is divided into male and female heads, with multiple core numbers to choose from, such as two cores, three cores, four cores, etc., among which the three-core XLR interface is the most common.

II. Digital audio interface

1. Optical fiber interface: The optical fiber interface transmits digital audio signals through optical conductors, and has the characteristics of fast transmission speed and strong anti-interference ability. It is usually used for connections between high-end audio devices, such as digital audio receivers, decoders, etc.

2. Coaxial interface: Similar to the optical fiber interface, the coaxial interface is also used to transmit digital audio signals. It uses coaxial cable as the transmission medium, with stable transmission quality and high anti-interference ability. However, it should be noted that although RCA plugs are sometimes used for coaxial output, the correct approach is to use BNC plugs because their impedance is more suitable for the S/PDIF format standard.

3. 3.5mm interface: The 3.5mm interface is one of the most commonly used interfaces on modern portable audio devices, such as mobile phones, tablets, MP3s, etc. It is mainly used to transmit analog audio signals and can connect headphones, external speakers and other devices. Due to its small and convenient characteristics, the 3.5mm interface has been widely used in daily life.