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4887-AF Speaker Frames / Rigging

JBL's VT4887-AF Array Frame for VT Systems can be used for supporting VT4887s or VT4881 Subwoofers. You can also use this versatile frame for ground stacking compact models.

JBL Speaker Frames / Rigging

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.

Active - A active circuit works with an external power supply and usually at low power. A passive circuit operates directly on a signal using the power coming from the surrounding circuitry.
This is the . Used . reason why an active crossover is, for the most part, placed before amps, containing integrated circuits (and line level signal processing). On the other hand a passive crossover is placed . Used . after amplifiers where power levels are much larger . ...

Ballyhoo - A set of programmed moves for automated lights where the lights move randomly within a specific area.. Used . . Used . ...

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

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

Watt - An international system for the measurement of the amount of power used by a device, usually electrical in nature, equal to one joule per second or one ampere of current flowing at one volt. The watt. Used . is named after James Watt for his contributions to the development of the steam engine and in turn its contribution to electrical power.. Used . ...

Power Distro - A power distro send power evenly and appropriately to various staging and rigging equipment to insure there is enough power to properly run the various equipment.. Used . . Used . ...

Speaker Frames / Rigging

Speaker frames/ rigging serve as an enclosure that holds the drivers together. It provides physical speaker mounting that prevents the sound waves from getting out the back of the drivers and colliding with the other sounds. This prevents sound cancellation, comb filtering and low quality of sound from the speakers. Speaker frames/ rigging commonly include a flyware component, rigging flyware, bumper and speaker hanging hardware. The set up and striking of the speaker frames can affect the quality of sound. The speaker system needs to have exclusive rigging hardware so that the enclosure can secure the lock down and protection of the components. Depending on the placement and suspension system of the speakers, the enclosure can include cabinets and quick attach pins and stainless steel pins to hold the components in place. Ideally, speaker frames/ rigging should become accustomed to heavy-duty usage and it should provide security for the speakers. The design should be secure, stable and should have a strong platform for the ground placement of speakers. The whole support system should be able to handle the weight of the components and it should be able to maintain a level ground stack. It should have multiple angles and rigging options for all kinds of hardware. Speaker frames/ rigging are a key feature in any sound system because it secures the location and placement of the speakers. The more flexible and simple the design, the better choice it will be. Each speaker should be placed properly so it can perform up to its optimum level.