Latency

Used more and more in the contemporary industry, latency is best described as the period of time between a command being sent to a device and that device's response. In MIDI instruments for example, latency measures the time between a command and the note played on an instrument. Latency has become an increasingly important feature especially as HDD recording grew more and more popular and playing/recording everything at the same time markers was crucial.

Lavalier

The lavalier is a small-size microphone used mostly attached to clothing or hanged around the neck. Lavaliers are used in a lot of situations where handheld microphones would look bad or their use would be highly impractical; TV reporters and guests, guides and other showbiz people, as well as army forces make thorough use of lavaliers. These mics are especially specced to eliminate the rumble an noise caused by contact with clothes.

LCD (Liquid Crystal Display)

LCD (Liquid Crystal Display) refers to the thinnest displays currently available on the market, used in a wide array of market segments, from dektop and notebook displays to the tiny screens on various portable devices, as for example handheld TVs, PDAs, and portable video game devices. The images displays on an LCD screen are obtained by overlapping (although the best term is sandwiching) a special electrically reactive substance between two electrodes. The color of said substance changes with the variations of the electrical current. Furthermore, LCD displays are a lot more economical than their CRT (Cathode-Ray) counterparts, since they're based on the principle of blocking light, rather than emitting it.

LED (Light-Emitting Diode)

Represents a type of semiconductor diode that emits visible or infrared light when current passes through it. The LEDs that emit in the visible spectrum are used as light sources (flashlights, car headlights, various indicator lights, etc.), while the LEDs that emit in the infrared spectrum are typically used for remote controls.

Line amp

A line amp is a device used to amplify and/or balance a signal so that it reaches a line level more suitable for being sent over longer runs of cable without losing strength or catching up too much interference. Unbalanced signal is usually susceptible to negatively react to interference and this is why line amps are used for sending sound over long distances by means of cable.

Line level signal

A line level signal denotes that an audio sound has the needed strength for transmitting analog data between two components such as CD, DVD, TV, mixing console and the likes of those. A line level signal is usually obtained by preamplifying a low-level source such as an electric guitar or microphone. The line levels in consumer audio gear are expressed in dBV and are voltage ratios, the most common nominal level being -10dBV.

Loudspeaker

Loudspeakers, often referred to as “transducers” or “drivers” are one of the key elements of sound reproduction. The basic principle is based on electromagnetism and electromechanics and it serves for transforming the electrical current into sound; the electrical current (audio signal) magnetizes a coil that is placed in a permanent magnetic field, causing it to move and setting the attached cone/diaphragm in motion, pushing air with various pressures and thus generating sound. Loudspeakers can have various dimensions and power ratings as well as be classified according to the frequencies they reproduce; the easiest way to categorize them is in tweeters (high frequency), midrange, woofers (low frequency) and subwoofers (ultra-low frequency).

Lowpass Filter (LPF)

The LPF is a filter with a special-design, meant to remove all frequencies above a user-defined cutoff point and let those equal or below this point pass on. While the main goal of the LPF is to cut down high frequencies, it is to be found in either active or passive forms, like the ”treble” control on amps or mixing consoles or passive components in guitars an basses; of course, LPFs are greatly used in all sorts of synthesizers.

Luminance

Luminance represents the photometric measurement unit of the density of luminous intensity in a given direction. The unit describes the quantity of light going through or being emitted by a certain area, and is reflected from a certain area under a certain angle. Practically, luminance is used mostly for indicating the level of brightness received by the human eye when looking at a certain surface from a certain angle. In the video industry, the luminance indicates the level of brightness provided by a certain display. In SI, luminance is measured in candela over square meter (cd/m2), an unit which is also known as a “nit”.