LFO may refer to:

LFO is a 2013 Scandinavian science fiction film directed and written by Antonio Tublén about a man who realizes that he can hypnotize with sound. He starts experimenting on his neighbors, where the abuse of power takes over and, eventually, severe consequences for mankind are at stake.

Plot

Robert Nord, an awkward man, spends most of his time playing with his synthesizers in his basement. After he has an argument with his wife Clara, whom he suspects is cheating on him, he returns to the basement again, to her annoyance. There, over the Internet, he discusses with several of his friends his belief that he has what he calls a "sound allergy" to the music that his wife enjoys. He proposes that a certain frequency could act as the opposite of this allergy and give him the peace that he desires. With the help of Sinus-San, one of his friends from the Internet, he makes a breakthrough, though he hides the extent of his success. When Simon and Linn move next door to him, he resolves to experiment on them over the objections of his wife.

LFO were a British electronic music act on the Warp Records label. LFO were pioneers of the bass-heavy techno, IDM, and acid house music of the late 1980s to mid-1990s. Originally, the group was composed of Gez Varley (born 1971) and Mark Bell. (1971–2014) After Varley left in 1996, LFO was Bell alone. Bell died in October 2014.

The group's name is derived from the abbreviation for the term low-frequency oscillator, a synthesizer function widely used in electronic music.

History

Varley and Bell met while studying at Leeds and gave their first track, the eponymous "LFO", to Nightmares on Wax. The popularity of the demo in clubs led to the track being released by the Sheffield-based Warp Records in 1990, and it was a Top 20 hit in the U.K., reaching number 12 in the singles charts in July.

Their follow-up single, "We Are Back", was released in the summer of 1991.

DJ Martin (Martin Williams) is credited as a cowriter and coproducer of the track "LFO" but was not a member of the group. Mark Bell explains:

Quartz is the second-most-abundant mineral in Earth's continental crust, after feldspar. Its crystal structure is a continuous framework of SiO₄silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO₂.

There are many different varieties of quartz, several of which are semi-precious gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Europe and the Middle East.

Etymology

The word "quartz" is derived from the German word "Quarz" and its Middle High German ancestor "twarc", which probably originated in Slavic, cf. Czech tvrdý ("hard"), Polish twardy ("hard"), Serbian and Croatian tvrd ("hard").

The Ancient Greeks referred to quartz as κρύσταλλος (krustallos) derived from the Ancient Greek κρύος (kruos) meaning "icy cold", because some philosophers (including Theophrastus) apparently believed the mineral to be a form of supercooled ice. Today, the term rock crystal is sometimes used as an alternative name for the purest form of quartz.

In Apple computer's OS X operating system, Quartz is the Quartz 2D and Quartz Compositor part of the Core Graphics framework. Quartz includes both a 2D renderer in Core Graphics and the composition engine that sends instructions to the graphics card. Because of this vertical nature, Quartz is often synonymous with Core Graphics.

In a general sense, Quartz or Quartz technologies can refer to almost every part of the Mac OS X graphics model from the rendering layer down to the compositor including Core Image and Core Video. Other Apple graphics technologies that use the "Quartz" prefix include:

Quartz 2D & Quartz Compositor

Quartz 2D is the primary two-dimensional (2D) text and graphics rendering library: It directly supports Aqua by displaying two-dimensional graphics to create the user interface, including on-the-fly rendering and anti-aliasing. Quartz can render text with sub-pixel precision; graphics are limited to more traditional anti-aliasing, which is the default mode of operation but can be turned off. In Mac OS X v10.4, Apple introduced Quartz 2D Extreme, which allows Quartz 2D to use supported GPUs for rendering. In Mac OS X 10.4, Quartz 2D Extreme is not enabled by default, because it may lead to video redraw issues or kernel panics. As of Mac OS X v10.5 Quartz 2D Extreme has been renamed to QuartzGL. However, it still remains disabled by default, as there are some situations where it can degrade performance, or experience visual glitches; it is a per-application setting which can be turned on if the developer wishes.

A crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a precise frequency. This frequency is commonly used to keep track of time, as in quartz wristwatches, to provide a stable clock signal for digital integrated circuits, and to stabilize frequencies for radio transmitters and receivers. The most common type of piezoelectric resonator used is the quartz crystal, so oscillator circuits incorporating them became known as crystal oscillators, but other piezoelectric materials including polycrystalline ceramics are used in similar circuits.

Quartz crystals are manufactured for frequencies from a few tens of kilohertz to hundreds of megahertz. More than two billion crystals are manufactured annually. Most are used for consumer devices such as wristwatches, clocks, radios, computers, and cellphones. Quartz crystals are also found inside test and measurement equipment, such as counters, signal generators, and oscilloscopes.