What are the advantages of optical fiber, coaxial, and Lotus on the motherboard audio interface? Which is better?

2021-02-01 18:28:13 ekL

Introduction to motherboard audio interface

        SPDIF is a digital audio signal. It is divided into two types, coaxial and optical fiber. In fact, the signals that they can transmit are the same, but the carrier is different, and the interface and connection appearance are also different. With the popularization of integrated circuits, many commonly used audio interfaces are also integrated on the motherboard. Most common motherboard audio interfaces such as digital TVs, PS4 game consoles, and Blu-ray players integrate SPDIF optical fiber audio interfaces and coaxial audio interfaces. There is only one of them, some have both, and some even integrate a 3.5mm analog audio interface; some high-end computer mainboards will also integrate SPDIF optical fiber audio interface and 3.5mm audio interface

Computer motherboard audio interface diagram

Computer motherboard audio interface diagram (here, Gigabyte motherboard is taken as an example)

Optical audio interface introduction

        Optical fiber audio conversion method: audio signal => digital signal => optical signal => digital signal => audio signal

        Advantages of optical fiber audio interface: long-distance transmission, no loss in the transmission process; optical fiber is the fastest transmission medium at present, the transmission speed is faster than coaxial; no need to consider the interface level and impedance, the interface is flexible and anti-interference ability Stronger

        Disadvantages of optical fiber audio interface: two conversion signals will cause data loss and disorderly data addition, which will affect the sound quality to a certain extent

Introduction of coaxial audio interface

        Coaxial audio conversion method: audio signal => digital signal => audio signal

        The coaxial audio interface Coaxial mainly provides the transmission of digital audio signals; the connectors are divided into two types: RCA (commonly known as lotus connectors) and BNC; it can transmit LPCM streams and surround sound compressed audio signals such as Dolby Digital and DTS.

        Advantages of coaxial audio interface: It reduces the conversion process of electricity-optical and optical-electricity to make the fidelity higher; the time base error of digital coaxial transmission is very small, so this transmission method has better performance on sound quality

        Disadvantages of the coaxial audio interface: the weakness of the coaxial signal line is that the long-distance transmission loss is large

        Since the coaxial audio also uses the Lotus connector, many people who don’t understand it directly connect to the traditional power amplifier that only supports analog audio signals without sound. The correct way is to use a coaxial to analog audio converter ( Such as: digital fiber coaxial to analog converter DAA) convert the audio into an analog signal and then connect it to the power amplifier

Digital optical coaxial to analog audio converter DAA

Digital optical coaxial to analog audio converter DAA

Introduction to Lotus Analog Audio Interface

        Lotus analog audio interface conversion method: audio signal => analog audio signal

        Lotus audio interface is divided into two types: L (left channel) and R (right channel). For stereo audio interfaces, the right channel is generally marked in red, and the left channel is marked in blue or white.

        Advantages of Lotus analog audio interface: It transmits analog audio signals, does not need to be decoded, and can be directly connected to the post-amplification processing; it is currently the most common and basic audio connection method

        Disadvantages: The analog audio signal is limited by bandwidth, and there is loss during transmission, which is not suitable for long-distance transmission

Schematic diagram of using digital to analog lotus audio connection speaker

Schematic diagram of using digital to analog lotus audio connection speaker

Which audio interface is better?

        For users who need to transmit audio over long distances, optical fiber audio interfaces are better; for music enthusiasts, it is better to use coaxial audio interfaces at home, and for users who only have analog audio, the Lotus audio interface is a better choice.

label: Audio port