Specifications System Type: Compact Bi-amplified 3-Way High Directivity Line Array Element Sensitivity: (2.83v/m) 97 dB LF, 101 dB MF/HF Components: 2 x 2168J 8 in. LF, 4 x 2104H 4 in. MF, 2 x 2407H HF NomInal Impedances: 8 ohm LF, 8 ohm MF/HF Horizontal Coverage (-6dB): 100 degrees nominal, 500Hz - 16kHz Power Rating: 1000W LF, 225W MF/HF Frequency Range (-10dB): 60 Hz - 22 kHz Dimensions (H x W x D): 279 mm x 787 mm - 417 mm (11 in. x 31 in. x 16.4 in.)
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.
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- Scaffolding is a temporary platform or framework, either supported from below or suspended, that is used to support people and material during the set up and deconstruction of a stage or venue.
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Used Cabinet Speakers
Speaker cabinets are specially engineered units in which audio equipment such as speakers and their associated hardware are mounted into. These cabinets can be very basic affairs, little more than a wooden case with no additional features other than one port for inputting a sound cable, or they can be incredibly complex cabinets with features ranging from numerous ports and internal baffles to acoustic insulation and composite materials used in their construction.
The main point of housing loud speakers and PA speakers in cabinets is not simply to make them look neat and tidy, although that is one benefit. The cabinet actually provides a useful function in preventing competing sound waves from interacting with each other and distorting the end product. This is because the diaphragm that the speaker driver uses to create the sound we hear generates sound waves both at the front and the rear, and these will be out of sync with each other, thus creating a distortion if not dealt with adequately.
Other side effects include echo and reverberation, as the sound waves would reach the audience at slightly different times as they travel on different paths through the loud speakers towards them.
In addition to minimizing these unwanted side effects, loud speakerâ??s cabinets also help to manage the vibrations which are caused by the driver frame, as well as the buildup of heat that is associated with amplifiers, driver voice coils and other moving components in PA speakers.