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| Type | Private (employee-owned) |
|---|---|
| Industry | Broadcasting |
| Founded | 1961 |
| Founder | John Cheney |
| Headquarters | , United States |
Key people | Tom Hartnett, Kris Bobo Specht (directors) |
| Website | comrex |
Comrex is an American corporation that designs and manufactures equipment for radio and television broadcasting.
Comrex was founded in 1961 by John Cheney, a broadcast engineer. His mission, as outlined in Comrex's inaugural press release, is "to apply advanced state of the art knowledge and techniques to the production of high quality, practical equipment which can be operated by non-technical personnel.”
Throughout the 1960s and 1970s, Comrex developed audio products for the television market. In 1968, founder John Cheney developed Models 7035 and 7040 receivers for wireless microphone systems.[ citation needed ] In 1973, the 450 RA/TA wireless microphone system, designed for TV news, is the first to enable reporters to move more than 1000 feet from the camera. [ citation needed ]In 1975, The Comrex wireless cue system, composed of the CTA cue transmitter and the CRA (now LPQRA) receiver, enables field reporters and producers to hear production audio and instructions, without a wired connection to a news van.[ citation needed ]
From the late 1970s onward, Comrex began building products for remote radio broadcasters:
From 1991 to 2000, Comrex released a series of ISDN codecs.
In 2006, Cheney's technical successor Tom Hartnett, in partnership with company co-director Kristine Bobo Specht, developed BRIC (Broadcast Reliable Internet Codec) technology. A full-featured suite of tools, BRIC incorporated sophisticated jitter buffers and proprietary algorithms to provide better quality audio over inherently unstable networks, like the public internet.
With BRIC in place, Comrex released the ACCESS codec in 2006. ACCESS was distinguished from its competitors by the hand-held design of the portable unit. Due to this form factor, and to the variety of networks on which it could function, ACCESS did not require the stationary set-up of the codecs that preceded it. [1] [2]
BRIC technology was also used to develop the BRIC-Link. An IP codec, BRIC-Link was intended for use as an STL or in other point-to-point applications. Since its introduction in 2009, it has been used widely in both radio and television by many organizations, including the NBA. [3]
In 2015, the BRIC-Link II, an updated version of the BRIC-Link, was introduced.
In 2023, Comrex introduced BRIC-Link III at the NAB 2022 show. BRIC-Link III has CrossLock VPN technology. [4]
In 2012, Comrex adapted BRIC technology to transport video as well as audio. [5] The resulting product, named LiveShot, could send video and audio bidirectionally over IP networks (including Wi-Fi and 3G/4G), with less than 500 milliseconds of delay. Weighing only 3 pounds, LiveShot was designed for news crews and ENG reporters who needed lightweight equipment.
In the years that followed, LiveShot was updated with CrossLock technology, a method of network bonding in which a VPN is established between the transmitting and receiving units. CrossLock greatly improved LiveShot's broadcasting reliability, especially over unstable IP networks. LiveShot's price-point, along with its versatility, have made it popular with small stations, educational organizations, and government facilities.
Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. Work on the standard began in 1980 at Bell Labs and was formally standardized in 1988 in the CCITT "Red Book". By the time the standard was released, newer networking systems with much greater speeds were available, and ISDN saw relatively little uptake in the wider market. One estimate suggests ISDN use peaked at a worldwide total of 25 million subscribers at a time when 1.3 billion analog lines were in use. ISDN has largely been replaced with digital subscriber line (DSL) systems of much higher performance.
Digital Audio Broadcasting (DAB) is a digital radio standard for broadcasting digital audio radio services in many countries around the world, defined, supported, marketed and promoted by the WorldDAB organisation. The standard is dominant in Europe and is also used in Australia, and in parts of Africa and Asia; as of 2022, 55 countries are actively running DAB broadcasts.
Shortwave radio is radio transmission using radio frequencies in the shortwave bands (SW). There is no official definition of the band range, but it always includes all of the high frequency band (HF), which extends from 3 to 30 MHz ; above the medium frequency band (MF), to the bottom of the VHF band.
In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves.
AM broadcasting is radio broadcasting using amplitude modulation (AM) transmissions. It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave transmissions, but also on the longwave and shortwave radio bands.
Digital Radio Mondiale is a set of digital audio broadcasting technologies designed to work over the bands currently used for analogue radio broadcasting including AM broadcasting—particularly shortwave—and FM broadcasting. DRM is more spectrally efficient than AM and FM, allowing more stations, at higher quality, into a given amount of bandwidth, using xHE-AAC audio coding format. Various other MPEG-4 codecs and Opus are also compatible, but the standard now specifies xHE-AAC.
Digital radio is the use of digital technology to transmit or receive across the radio spectrum. Digital transmission by radio waves includes digital broadcasting, and especially digital audio radio services.
In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. The antenna intercepts radio waves and converts them to tiny alternating currents which are applied to the receiver, and the receiver extracts the desired information. The receiver uses electronic filters to separate the desired radio frequency signal from all the other signals picked up by the antenna, an electronic amplifier to increase the power of the signal for further processing, and finally recovers the desired information through demodulation.
In analog telephony, a telephone hybrid is the component at the ends of a subscriber line of the public switched telephone network (PSTN) that converts between two-wire and four-wire forms of bidirectional audio paths. When used in broadcast facilities to enable the airing of telephone callers, the broadcast-quality telephone hybrid is known as a broadcast telephone hybrid or telephone balance unit.
HD Radio (HDR) is a trademark for an in-band on-channel (IBOC) digital radio broadcast technology. HD radio generally simulcasts an existing analog radio station in digital format with less noise and with additional text information. HD Radio is used primarily by AM and FM radio stations in the United States, U.S. Virgin Islands, Canada, Mexico and the Philippines, with a few implementations outside North America.
FM broadcasting is a method of radio broadcasting that uses frequency modulation (FM) of the radio broadcast carrier wave. Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to transmit high-fidelity sound over broadcast radio. FM broadcasting offers higher fidelity—more accurate reproduction of the original program sound—than other broadcasting techniques, such as AM broadcasting. It is also less susceptible to common forms of interference, having less static and popping sounds than are often heard on AM. Therefore, FM is used for most broadcasts of music and general audio. FM radio stations use the very high frequency range of radio frequencies.
A wireless microphone, or cordless microphone, is a microphone without a physical cable connecting it directly to the sound recording or amplifying equipment with which it is associated. Also known as a radio microphone, it has a small, battery-powered radio transmitter in the microphone body, which transmits the audio signal from the microphone by radio waves to a nearby receiver unit, which recovers the audio. The other audio equipment is connected to the receiver unit by cable. In one type the transmitter is contained within the handheld microphone body. In another type the transmitter is contained within a separate unit called a "bodypack", usually clipped to the user's belt or concealed under their clothes. The bodypack is connected by wire to a "lavalier microphone" or "lav", a headset or earset microphone, or another wired microphone. Most bodypack designs also support a wired instrument connection. Wireless microphones are widely used in the entertainment industry, television broadcasting, and public speaking to allow public speakers, interviewers, performers, and entertainers to move about freely while using a microphone without requiring a cable attached to the microphone.
A POTS codec is a type of audio coder-decoder (codec) that uses digital signal processing to transmit audio digitally over standard telephone lines at a higher level of audio quality than the telephone line would normally provide in its analog mode. The POTS codec is one of a family of broadcast codecs differentiated by the type of telecommunications circuit used for transmission. The ISDN codec, which instead uses ISDN lines, and the IP codec which uses private or public IP networks are also common.
WirelessHD, also known as UltraGig, is a proprietary standard owned by Silicon Image for wireless transmission of high-definition video content for consumer electronics products. The consortium currently has over 40 adopters; key members behind the specification include Broadcom, Intel, LG, Panasonic, NEC, Samsung, SiBEAM, Sony, Philips and Toshiba. The founders intend the technology to be used for Consumer Electronic devices, PCs, and portable devices.
Audio over IP (AoIP) is the distribution of digital audio across an IP network such as the Internet. It is used increasingly to provide high-quality audio feeds over long distances. The application is also known as audio contribution over IP (ACIP) in reference to the programming contributions made by field reporters and remote events. Audio quality and latency are key issues for contribution links. In the past, these links have made use of ISDN services but these have become increasingly difficult or expensive to obtain.
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is widely used in modern technology, in radio communication, radar, radio navigation, remote control, remote sensing, and other applications.
Wireless Home Digital Interface (WHDI) is a consumer electronic specification for a wireless HDTV connectivity throughout the home.
Wideband audio, also known as wideband voice or HD voice, is high definition voice quality for telephony audio, contrasted with standard digital telephony "toll quality". It extends the frequency range of audio signals transmitted over telephone lines, resulting in higher quality speech. The range of the human voice extends from 100 Hz to 17 kHz but traditional, voiceband or narrowband telephone calls limit audio frequencies to the range of 300 Hz to 3.4 kHz. Wideband audio relaxes the bandwidth limitation and transmits in the audio frequency range of 50 Hz to 7 kHz. In addition, some wideband codecs may use a higher audio bit depth of 16 bits to encode samples, also resulting in much better voice quality.
aptX is a family of proprietary audio codec compression algorithms owned by Qualcomm, with a heavy emphasis on wireless audio applications.
IP codecs are used to send video or audio signals over an IP network such as the Internet. The initials "IP" here stand for "Internet Protocol", while the term "codec" is short for "encoder/decoder" or "compressor/decompressor".
