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VT4880DP Line Array Speakers

The VT4880DP Full Size Powered Dual 18 inch Arrayable Subwoofer is designed to deliver highquality reinforcement of VLF (Very Low Frequency) musical information for a variety of applications including concert audio, corporate A/V and theatrical presentations of all types for both portable users and performance-Venue applications.
Ideal comPanion to VT4889DP full size powered three-way systems.

JBL Line Array Speakers

James Bullough Lansing was born James Martini, 14 January 1902, in Macoupin County, Millwood Township, Illinois. His parents were Henry Martini, born in St. Louis, Missouri, and Grace Erbs Martini, born in Central City, Illinois. The elder Martini was a coal mining engineer, and his work required that the family moved about quite a bit during Lansing's early years. Lansing was the ninth of fourteen children, one of whom died in infancy. For a short time, Lansing lived with the Bullough family in Litchfield, Illinois. He later took their name when he changed his from Martini to Lansing. Not much is known about Lansing's early days, and we are indebted to Bill Martin, one of three surviving brothers, for providing most of the information presented here. Lansing graduated the eighth grade at the Lawrence School in Springfield, Illinois. He also attended the Springfield, Illinois, High School. Later, he took courses in a small business college in Springfield. As a young lad he was very interested in all things electrical and mechanical. At about the age of 10, he built a Leyden Jar which he used to play pranks on his playmates. He also constructed crystal sets, and at one time, probably about the age of 12 or so, built a small radio transmitter from scratch. The signals from this set were apparently strong enough to reach the Great Lakes Naval Station in Illinois; naval personnel determined the source of these signals and later supervised the timely dismantling of the young Lansing's radio transmitter. For a while Lansing worked as an automotive mechanic, specializing in fine engine repair work. He attended an automotive school for mechanics in Detroit through the courtesy of the dealer he worked for in Springfield. Lansing's mother died 1 November 1924 at the age of 56, and at that time Lansing left home. As best we can determine, he went directly to Salt Lake City. Mrs. Lansing, the former Glenna Peterson of Salt Lake City, tells of meeting Lansing in 1925 in that city. At the time he was working for a radio station as an engineer. In addition, he worked for the Baldwin loudspeaker company in Salt Lake City for a time. He also met his future business partner, Ken Decker, in Salt Lake City.

Entire Stages - An entire stage is a complete stage that generally include platforms, stairs and sometimes roofing, ranging in size from small easy to transport stages to large staging systems.. Used . . Used . ...

Automated Light - Automated Lights were originally used in 1972, but the first computer-controlled stage lighting fixtures began to gain widespread acceptance in the concert industry in the early 1980's. As the digital. Used . age progressed, the cost of these fixtures was reduced and they slowly started being used in more 'traditional' theatrical environments. Intelligent fixtures are currently used in almost all. Used . major theatrical productions.

Usually relying on compact arc lamps as a light source, these fixtures generally use stepper motors connected to varying internal devices to manipulate the light bef...

Compression and Dynamics - Compression is the reduction of the dynamic range of a sound to avoid unintentional changes and increases in the amplitude. Compression is generally used to make an audio signal sound louder without i. Used . ncreasing its peak amplitude. By compressing or limiting the peak signals, it becomes possible to increase the overall volume of the signal without exceeding the dynamic limits of a device or. Used . medium. This causes quiet sounds to become louder, while louder sounds remain unchanged....

Lighting - Lighting or stage lighting is a tool and art form in the production of theater, dance, opera and other performance arts. Several different types of stage lighting instruments are used in the pursuit o. Used . f the various principles or goals of lighting ranging from simple illumination to mood setting. Lighting also applies architectural accents to add color or shading to indoor and outdoor sett. Used . ings....

LED - An LED or light emitting diode is simply a tiny light bulb that fits into an electrical circuit. However, unlike ordinary bulbs, LEDs don't have a filament that will burn out and generate very little . Used . heat. They are illuminated by the movement of electrons in a semiconductor material and last as long as a standard transistor.. Used . ...

Line Array Speakers

Line array speakers make up a loudspeaker system to create a sound source that produces an evenly distributed sound output. The driver of each line array element is close enough to the driver of the next element to create constructive interference. The resulting sound waves go farther than sound waves from traditional loudspeakers. Line array systems date back to the early days of research in acoustics. Many old town halls and public venues still have old line source boxes which were found to project voice well though they are much smaller than horn-loaded speakers. These days, line array speakers use different drivers for high-, mid- and low-frequency passbands that must be in line. Each enclosure must be set up closely to form columns composed of these drivers. To increase the frequency range and maximum sound pressure, the number of drivers per enclosure must be increased. The orientation of line array speakers may vary. Vertical arrays are excellent for focusing sound at audiences without wasting output energy on ceilings or empty air above the audience because of its very narrow vertical output with a normally-wide horizontal pattern. On the other hand, horizontal line arrays have a very narrow horizontal output with a tall vertical pattern. For hanging concert speakers which are usually part of a concert reinforcement system, enclosures are set up together using a specialized rigging hardware and they hang from a single point. These line array speakers are curved backward at the lower portion so that the sound will reach more audience.