Line level is a term used to denote the strength of an audio signal used to transmit analog sound information between audio components such as CD and DVD players, TVs, audio amplifiers, and mixing consoles. An analog or analogue signal is any continuously variable signal. ... This article or section does not cite its references or sources. ... DVD (commonly Digital Versatile Disc or Digital Video Disc) is an optical disc storage media format that can be used for data storage, including movies with high video and sound quality. ... See TV (disambiguation) for other uses and Television (band) for the rock band European networks National In much of Europe television broadcasting has historically been state dominated, rather than commercially organised, although commercial stations have grown in number recently. ... Mission Cyrus 1 Hi Fi integrated audio amplifier An audio amplifier is an electronic amplifier that works with audio frequencies (generally 20 hertz to 20,000 hertz). ... BBC Local Radio Mark III radio mixing desk In professional audio, a mixing console, mixing desk (Brit. ...

In contrast to line level, there are weaker audio signals, such as those from microphones and instrument pickups, and stronger signals, such as those used to drive headphones and loudspeakers. The strength of the various signals is not merely measured by the output voltage of a device, but also by the current available to drive different loads. A microphone, sometimes referred to as a mike or mic (both IPA pronunciation: ), is an acoustic to electric transducer that converts sound into an electrical signal. ... A picku device acts as a transducer that captures mechanical vibrations (usually from suitably equipped stringed instruments such as the electric guitar, electric bass guitar or electric violin) and converts them to an electronic signal which can be amplified and recorded. ... Headphones (also known as earphones, earbuds, stereophones, headsets, or by the slang term cans) are a pair of transducers that receive an electrical signal from a media player or receiver and use speakers placed in close proximity to the ears (hence the name earphone) to convert the signal into audible... A 3. ...

Depending on the application, line levels are stated as voltage ratios expressed in decibels. These ratios are relative to different reference voltages in units of either decibel volts (dBV) or decibels unloaded (dBu). The decibel (dB) is a measure of the ratio between two quantities, and is used in a wide variety of measurements in acoustics, physics and electronics. ... The decibel (dB) is a measure of the ratio between two quantities, and is used in a wide variety of measurements in acoustics, physics and electronics. ...

Consumer audio equipment line levels are rated in dBV, and the most commonly used nominal level for such equipment is −10 dBV, which corresponds to a sine wave of about 0.3162 volts RMS. The absolute reference voltage is 1 V_RMS ^[1]. This reference voltage represents 1 milliwatt at 1000 ohms. Josephson junction array chip developed by NIST as a standard volt. ... In mathematics, the root mean square or rms is a statistical measure of the magnitude of a varying quantity. ...

Professional audio equipment line levels are rated in dBu, and the most commonly used nominal level for such equipment is +4 dBu, which corresponds to a sine wave of about 1.228 volts RMS. The absolute reference voltage is 0.775 V_RMS. This reference voltage corresponds to 1 mW of power at 600 ohms.

Line-level in traditional signal paths

Acoustic sounds (such as voices or a musical instruments) are often recorded with transducers (microphones and pickups) that produce weak electrical signals. These signals must be amplified to line level, where they are more easily manipulated by other devices such as mixing consoles and tape recorders. Such amplification is performed by a device known as a preamplifier or "preamp". After manipulation at line level, signals are then typically sent to a device known as a power amplifier, where they are amplified to levels that can drive headphones or loudspeakers, which convert the signals back into sounds that can be heard through the air. Acoustics is a branch of physics and is the study of sound (mechanical waves in gases, liquids, and solids). ... In music, a register is the relative height or range of a note, set of pitches or pitch classes, melody, part, instrument or group of instruments. ... A musical instrument is a device constructed or modified with the purpose of making music. ... A transducer is a device, usually electrical or electronic, that converts one type of energy to another. ... A microphone, sometimes referred to as a mike or mic (both IPA pronunciation: ), is an acoustic to electric transducer that converts sound into an electrical signal. ... A picku device acts as a transducer that captures mechanical vibrations (usually from suitably equipped stringed instruments such as the electric guitar, electric bass guitar or electric violin) and converts them to an electronic signal which can be amplified and recorded. ... An example of a typical high-end stereo preamplifier. ... In-ear headphones Headphones (also known as earphones, stereophones, headsets, or the slang term cans) is a transducer that receives an electrical signal from a media player or receiver and uses speakers placed in close proximity to the ears (hence the name earphone) to convert the signal into audible sound... A 3. ...

Most phonographs also have a low output level and require a preamp; typically, a home stereo amplifier will have a special phono input with a built-in preamp, which also modifies the signal in order to account for the attenuation used in phonography of low-frequency signals. Edison cylinder phonograph ca. ... The phono input are a set of input jacks, usually behind a stereo receiver to which a phonograph or turntable is attached. ... Attenuation is the reduction in amplitude and intensity of a signal with respect to distance traveled through a medium. ...

See also

• Nominal level
• Alignment level

Nominal level is the operating level at which an electronic signal processing device is designed to operate. ... The Alignment level in an audio signal chain or on an audio recording is an anchor point that represents a reasonable or typical level. ...

References

1. ^ Tangible Tech Audio Basics

Bibliography

1. (1998) in Glenn M. Ballou: Handbook for Sound Engineers: The New Audio Cyclopedia, Second Edition. Focal Press. ISBN 0-240-80331-0. .

External links

• Conversion of voltage to voltage level dBu, dBV, and dBm
• Units dBV in consumer equipment, dBu in professional equipment
• The Decibel