Line In
Line In
Line In is an audio input port on a sound card or other audio device that allows an external audio source, such as a microphone or audio player, to be connected to the computer. It is typically used to record audio or to add external audio to a computer’s sound output.
What does Line In mean?
Line In is an audio input jack found on electronic devices, typically used to connect external audio sources like CD players, turntables, and tape decks to amplifiers, mixers, or sound cards. It allows the external audio source to be routed into the Device‘s Internal sound Processing system for playback or recording.
The Line In jack is usually represented by a thin, horizontal line above an arrow pointing inward, indicating the direction of the audio signal flow. It is commonly color-coded white or black, but variations exist.
In terms of signal levels, Line In typically handles higher-level signals than microphone inputs but lower levels than speaker outputs. This is because external audio sources often provide their own amplification, reducing the need for excessive gain from the receiving device.
Applications
Line In is extensively used in various technological applications due to its ability to connect external audio sources to a wide Range of devices. Some key applications include:
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Audio Mixing and Editing: In audio production, Line In is used to connect external instruments, synthesizers, and media players to mixers and sound cards for mixing, recording, or playback.
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Music Playback: Consumer audio devices such as stereos, speakers, and boomboxes often have Line In jacks to allow users to connect external audio sources like MP3 players, CD players, or laptops to enjoy music from various sources.
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Home Theater Systems: Home theater receivers and soundbars commonly feature Line In jacks for connecting external devices like DVD players, game consoles, or Blu-ray players to the surround sound system for enhanced audio experiences.
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Microphone Pre-Amplification: Some devices, such as portable recorders or digital mixers, may have a Line In jack that doubles as a microphone pre-amplifier, providing additional gain and impedance matching for low-level microphone signals.
History
The concept of Line In inputs can be traced back to the early days of audio equipment, when external audio sources were connected to amplifiers and radios using dedicated terminals. In the 1950s, standardized audio jacks began to emerge, with the quarter-inch (6.35mm) jack becoming the most common for Line In connections.
As technology advanced, Line In jacks became an integral part of mixers and sound reinforcement systems, allowing for the seamless integration of multiple external audio sources. In the early days of Digital Audio, sound cards incorporated Line In jacks to facilitate the digitization of analog audio signals for recording and playback on computers.
Over the years, Line In jacks have continued to be incorporated into various electronic devices, from audio interfaces and home theater systems to portable music players and smartphones. Today, it remains a widely used and versatile audio input for connecting external audio sources to a diverse range of technological applications.