The VerTec VT4887 Three-Way Line Array Element is designed to deliver high-quality reinforcement of music and speech in a variety of applications including concert audio and corporate A/V presentations of all types for both portable users and fixed venue installations.
The VT4887 is a compact, lightweight enclosure housing two 8? woofers, four 4? midrange radiators, and two high frequency compression drivers. Advanced components provide the highest power-to-weight ratio of any speaker system in its class.
Enclosure features foam-backed low frequency grilles, dense protective foam inserts for midrange apertures, and a fine steel mesh grille to protect high-frequency apertures. Speaker cones are treated with weather-resistant compounds. Rigging tubes made of hard-black anodized 6061-T6 Aluminum. Hinge bars made from premium-grade chromoly alloy steel, with epoxy powder coating over zinc-plated surfaces. Cadmium-plated hinge pins and stainless steel quick-release pin lanyards to resist corrosion and weather damage.
VERTEC arrays are rigid for maximum support strength, yet flexible in design and application. The VT4887?s suspension hardware relies on quick-release pins and endmounted metal tubes to couple adjacent VT4887?s together. Enclosure ships with integral front and rear hinge bar set. Protective grille cover/wheel board and soft cover to ensure handy transport for rough road conditions, purchased separately as VT4887-ACC.
- Advanced technology components: Differential Drive, neodymium magnet, dual voice coil, Direct Cooled cone transducers for low weight and high output.
- Waveguide units couple to create precision HF vertical slot aperture.
- Radiation Boundary Integrator (RBI): Patented technology integrates output of individual bandpass elements.
- Advanced construction techniques and hybrid materials provide exceptionally rigid, lightweight enclosure construction.
- Rugged DuraFlex exterior finish weatherized components.
- Patented, integrated S.A.F.E. suspension system: premium heat-treated alloys provide high-strength, reliable hanging arrays.
- Pre-engineered to accept optional JBL DrivePack amplified electronics package. Rear-panel mechanical attachments and electrical connections ensure upgrade path to self-powered system.
- For use in stand-alone arrays or in combination with other VERTEC DP SERIES system products.
JBL is an American company that manufactures audio equipment, including loudspeakers and headphones. There are two independent divisions within the company; JBL Consumer produces audio equipment for the consumer home market, while the JBL Professional produces professional equipment for the studio, installed sound, tour sound, portable sound (production and DJ), and cinema markets. JBL is owned by Harman International Industries, a subsidiary of South Korean company Samsung Electronics.
JBL was founded by James Bullough Lansing (1902–1949) who was an American audio engineer and loudspeaker designer most notable for establishing two audio companies that bear his name, Altec Lansing and JBL, the latter taken from his initials.Early products included the model 375 high-frequency driver and the 075 ultra high frequency (UHF) ring-radiator driver. The ring-radiator drivers are also known as "JBL bullets" because of their distinctive shape. The 375 was a re-invention of the Western Electric 594 driver but with an Alnico V magnet and a four-inch voice coil. The 375 shared the same basic magnet structure as the D-130 woofer. JBL engineers Ed May and Bart N. Locanthi created these designs.
In 1955 the brand name JBL was introduced to resolve ongoing disputes with Altec Lansing Corporation. The company name "James B. Lansing Sound, Incorporated", was retained, but the logo name was changed to JBL with its distinctive exclamation point.
The JBL 4320 series studio monitor was introduced through Capitol Records in Hollywood and became the standard monitor worldwide for its parent company, EMI. JBL's introduction to rock and roll music came via the adoption of the D130 loudspeaker by Leo Fender's Fender Guitar Company as the ideal driver for electric guitars.
In 1969, Thomas sold JBL to the Jervis Corporation (later renamed "Harman International"), headed by Sidney Harman. The 1970s saw JBL become a household brand, starting with the famous L-100, which was the best-selling loudspeaker model of any company to that time. The 1970s were also a time of major JBL expansion in the professional audio field from their studio monitors.
By 1977, more recording studios were using JBL monitors than all other brands combined, according to a Billboard survey. The JBL L-100 and 4310 control monitors were popular home speakers. In the late 1970s, the new L-series designs L15, L26, L46, L56, L86, L96, L112, L150, and later the L150A and flagship L250 were introduced with improved crossovers, ceramic magnet woofers, updated midrange drivers, and aluminum-deposition phenolic resin tweeters.
In the mid-1980s the designs were again updated and redesigned with a new titanium-deposition tweeter diaphragm. The new L-series designations being the L20T, L40T, L60T, L80T, L100T, the Ti-series 18Ti, 120Ti, 240Ti, and the flagship 250Ti. To test speaker drivers, JBL in Glendale and Northridge used the roof as an outdoor equivalent to an anechoic chamber.
Over the next two decades, JBL went more mass-market with their consumer (Northridge) line of loudspeakers. At the same time, they made an entry into the high-end market with their project speakers, consisting of the Everest and K2 lines.
JBL became a prominent supplier to the tour sound industry, their loudspeakers being employed by touring rock acts and music festivals.
JBL products were the basis for the development of THX loudspeaker standard, which resulted in JBL becoming a popular cinema loudspeaker manufacturer.
Active: Powered. An active crossover is electrically powered and divides the line-level signal prior to amplification. An active speaker includes an active crossover and built-in amplifier.
Actuality: Audio from an announcer speaking.
Amplifier: A component that increases the gain or level of an audio signal.
Balanced Input: A connection with three conductors: two identical signal conductors that are 180 degrees out of phase with each other, and one ground. This type of connection is very resistant to line noise.
Bandpass: A two-part filter that cuts both higher and lower frequencies around a center band. A bandpass enclosure cuts high frequencies by acoustic cancellation and low frequencies by natural physical limitations on bass response.
Bandwidth: In audio, the range of frequencies a device operates within. In video, the range of frequencies passed from the input to the output. Bandwidth can also refer to the transmission capacity of an electronic communications device or system the speed of data transfer,is very important when planning a meeting for the attendees to stay connected.
Bass: Low frequencies; those below approximately 200 Hz.
Bi-Wiring: A method of connecting an amplifier or receiver to a speaker in which separate wires are run between the amp and the woofer and the amp and the tweeter.
Boost: To increase, make louder or brighter; opposite of attenuate.
Bridging: Combining two channels of an amplifier to make one channel that more powerful. One channel amplifies the positive portion of an audio signal and the other channel amplifies the negative portion, which are then combined at the output.
CD: Compact Disc. Ubiquitous digital audio format. Uses 16-bit/44.1-kHz sampling rate PCM digital signal to encode roughly 74 or 80 minutes of two- channel, full-range audio onto a 5-inch disc.
CD-R: Recordable Compact Disc.
CD-RW: Rewritable Compact Disc.
Channel: In components and systems, a channel is a separate signal path. A four-channel amplifier has at least four separate inputs and four separate outputs.
Coloration: Any change in the character of sound (such as an overemphasis on certain tones) that reduces naturalness.
Crossover: A component that divides an audio signal into two or more ranges by frequency, sending, for example, low frequencies to one output and high frequencies to another. An active crossover is powered and divides the line-level audio signal prior to amplification. A passive crossover uses no external power supply and may be used either at line level or, more commonly, at speaker level to divide the signal after amplification and send the low frequencies to the woofer and the high frequencies to the tweeter.
Crossover Frequency: The frequency at which an audio signal is divided. 80 Hz is a typical subwoofer crossover point and is the recommended crossover point in theatrical and home THX systems. Frequencies below 80 Hz are sent to the subwoofer signals above 80 Hz are sent to the main speakers.
Cut: To reduce, lower; opposite of boost.
Decibel (dB): A logarithmic measurement unit that describes a sound`s relative loudness, though it can also be used to describe the relative difference between two power levels. A decibel is one tenth of a Bel. In sound, decibels generally measure a scale from 0 (the threshold of hearing) to 120-140 dB (the threshold of pain). A 3dB difference equates to a doubling of power. A 10dB difference is required to double the subjective volume. A 1dB difference over a broad frequency range is noticeable to most people, while a 0.2dB difference can affect the subjective impression of a sound.
Delay: The time difference between a sonic event and its perception at the listening position (sound traveling through space is delayed according to the distance it travels). People perceive spaciousness by the delay between the arrival of direct and reflected sound (larger spaces cause longer delays.
Diaphragm: The part of a dynamic loudspeaker attached to the voice coil that produces sound. It usually has the shape of a cone or dome.
Diffusion: In audio, the scattering of sound waves, reducing the sense of localization. In video, the scattering of light waves, reducing hot spotting, as in a diffusion screen.
Digital Audio Server: Essentially a hard drive, a digital audio server stores compressed audio files (like MP3 or WMA). Most include the processing to make the files, and all have the ability to play them back.
Direct-Stream Digital: A format for encoding high-resolution audio signals. It uses a 1-bit encoder with a sampling rate of 2,822,400 samples per second (verses 44,100 for CD). Used to encode six high-resolution channels on SACD.
Dispersion: The spread of sound over a wide area.
Distortion: Any undesired change in an audio signal between input and the output.
DNR: Dynamic Noise Reduction. A signal-processing circuit that attempts to reduce the level of high-frequency noise. Unlike Dolby NR, DNR doesn’t require preprocessing during recording.
Dolby B: A noise-reduction system that increases the level of high frequencies during recording and decreases them during playback.
Dolby C: An improvement on Dolby B that provides about twice as much noise reduction.
Dolby Digital: An encoding system that digitally compresses up to 5.1 discrete channels of audio (left front, center, right front, left surround, right surround, and LFE) into a single bitstream, which can be recorded onto a DVD, HDTV broadcast, or other form of digital media. When RF-modulated, it was included on some laser discs, which requires an RF-demodulator before the signal can be decoded. Five channels are full-range; the .1 channel is a band-limited LFE track. A Dolby Digital processor (found in most new receivers, preamps, and some DVD players) can decode this signal back into the 5.1 separate channels. Most films since 1992`s Batman Returns have been recorded in a 5.1 digital format, though a number of films before that had 6-channel analog tracks that have been remastered into 5.1.
Dolby EX: An enhancement to Dolby Digital that adds a surround back channel to 5.1 soundtracks. The sixth channel is matrixed from the left and right surround channels. Often referred to as 6.1. Sometimes referred to as 7.1 if the system uses two surround back speakers, even though both speakers reproduce the same signal. Software is backwards-compatible with 5.1 systems, but requires an EX or 6.1 processor to obtain additional benefit.
Dolby Pro Logic: An enhancement of the Dolby Surround decoding process. Pro Logic decoders derive left, center, right, and a mono surround channel from two-channel Dolby Surround encoded material via matrix techniques.
Dolby Pro Logic II: An enhanced version of Pro Logic. Adds improved decoding for two-channel, non-encoded soundtracks and music.
Driver: A speaker without an enclosure; also refers to the active element of a speaker system that creates compressions and rarefactions in the air.
DSP: Digital Signal Processing. Manipulating an audio signal digitally to create various possible effects at the output. Often refers to artificially generated surround effects derived from and applied to two-channel sources.
DTS: Digital Theater Systems. A digital sound recording format, originally developed for theatrical film soundtracks, starting with Jurassic Park. Records 5.1 discrete channels of audio onto a handful of laser discs, CDs, and DVDs. Requires a player with DTS output connected to a DTS processor.
DTS ES: An enhanced version of the 5.1 DTS system. Like Dolby’s Surround EX, a sixth channel is added. In some cases (DTS ES Discrete), the sixth channel is discrete. Software is backwards-compatible with 5.1 systems, but requires an ES or 6.1 processor to obtain additional benefit. Neo: 6 is a subset of DTS ES that creates 6.1 from material with fewer original channels.
Dynamic Range: The difference between the lowest and the highest levels; in audio, it’s often expressed in decibels. In video, it’s listed as the contrast ratio.