Tech Talk

100v line - or Constant Voltage Loudspeaker System provides a stable method of audio distribution/installation using voltage (provided via an amplifier) and step-down transformers (normally mounted within the loudspeakers). Advantages of 100v systems are the distance/lengths of the loudspeaker cable runs and the ability to add or remove loudspeakers from the system.

24fps (24p) - Refers to a video format that operates at 24 frames per second remove with progressive scanning.

4K Resolution - 4K Ultra High Definition (UHD) is the next generation of improved resolution television, providing 3840 x 2160 pixels.

5 GHz - Wireless technology using unlicensed 5GHz frequency bands.

50 Hz - Common Frame rate (image change rate) for video within Europe.

60 Hz - Common Frame rate (image change rate) for video within America/Japan.

5.1 - Surround sound that delivers 6 Channels of audio, five standard speakers, and 1 Sub-woofer.

7.1 - Surround sound that delivers 8 Channels of audio, seven standard speakers, and 1 Sub-woofer.

acoustics - The science of sound wave behavior in the air.

ADC (A/D Converter) - An IC Chip that converts analog Audio-Visual signals into digital.

AFILS - Audio Frequency Induction Loop System. See Induction Loop System.

AES - Audio Engineering Society.

alternating current (AC) - an electric current that reverses its direction periodically.

ambient light - all light in a viewing room produced by sources other than the display.

ambient noise - sound that is extraneous to the intended, desired, intentional, audio, and background noise.

amplifier - an electronic device for increasing the strength of electrical signals.

amplitude - the strength of an electronic signal as measured by the height of its waveform.

analog - a method of transmitting information by a continuous but varying signal.

angularly reflective screen - a screen that reflects light back to the viewer at a complementary angle.

ANSI - American National Standards Institute.

AoIP - Audio over IP allows audio signals to be transmitted via LAN, WAN, or web to IP-addressable endpoints, IP loudspeakers or IP amplifiers for control and distribution to multi-zone, multi-site PA systems.

aperture - an opening in a lens regulating the amount of light passing through the lens to the image.

artifacts - small disturbances that affect the quality of a signal.

aspect ratio - the ratio of image width to image height (typically widescreen or standard).

attenuate - to reduce the amplitude (strength) of a signal or current.

audio processor - an electronic device used to manipulate audio signals in some manner.

audio signal - an electrical representation of sound.

audio transduction - converting acoustical energy into electrical energy, or electrical energy back into acoustical energy.

bands - a grouping or range of frequencies.

bandwidth - a measure of information carrying capacity without distortion.

bandwidth limiting - the result of encoding a higher quality signal into a lower quality form, such as RGB converted into S-Video.

baseband - video signal that has not been modulated.

bend radius - maximum amount a conductor can be bent before excessive attenuation is encountered, signal integrity is compromised, or the conductor breaks.

bi-directional polar pattern - the shape of the region where some microphones will be most sensitive to sound from the front and rear while rejecting sound from the top, bottom, and sides.

bit depth - the number of bits used to describe data.

Bit - In computer and digital terminology, a bit is the smallest unit of data. It is expressed in binary notation so that it is either 0 or 1–an 'off' or an 'on' switch. The word 'bit' is an amalgam of 'binary' and 'digit'.

Bit rate - The number of bits that are transferred or processed per unit of time.

Bitstream - Digital form of multi-channel audio data (e.g., 5.1 Channel) before it is decoded into its various formats.

blocking - pieces of wood that have been inserted between structural building elements to provide a secure mounting point for finish materials or products.

block diagram - an illustration of the signal path through a given system.

BNC - a professional type of video connector featuring a two-pin lock.

boundary microphone - a microphone that relies on reflected sound from a surrounding surface.

buffer amplifier - an electronic device that provides some isolation between other components.

bus (buss) - a wiring system that delivers power and data to various devices.

byte - an 8-bit word is called a byte. The acronym for byte is the upper-case B.

BGM Background Music - low-level music distributed via a PA system.

Bluetooth - a wireless protocol for exchanging data over short distances from fixed and mobile devices. Commonly used for audio and mobile telephone headsets / hands-free applications. Operates in the 2.4GHz band.

Block Noise Reduction - MPEG digital video compression works by compressing square areas of pixels. Under some conditions, an artifact called 'block noise' can occur in the picture. Block Noise Reduction processes the noise blocks so that they become less visible.

Blu-ray - The Blu-ray Disc™ is a high-density optical disc format designed for storage of high-definition video and data.

cable - an assembly of more than one conductor (wire).

capacitance - the ability of a nonconductive material to develop an electrical charge which can distort an electrical signal.

capacitive reactance - the opposition a capacitor offers to alternating current flow. Capacitive reactance decreases with increasing frequency or, for a given frequency; the capacitive reactance decreases with increasing capacitance. The symbol for capacitive reactance is XC.

captive screw connector - sometimes called a Phoenix(R) connector, it is a molded plastic connector whose termination requires that you strip and slide a wire directly into a slot on the connector. A set screw then pushes a gate down to hold the wire in place.

cardioid - heart-shaped region where some microphones will be most sensitive to sound predominately from the front of the microphone diaphragm and reject sound coming from the sides and rear.

carrier - modulated frequency that carries video or audio signal.

Category 5 (Cat 5) - the designation for 100-ohm unshielded twisted-pair cables and associated connecting hardware whose characteristics are specified for data transmission up to 100 Mb/s. (Part of the EIA/TIA 568A standard.)

category 5e (Cat 5e) - an enhanced version of the Cat-5 cable standard that adds specifications for far-end crosstalk. (Part of the EIA/TIA 568A standard.)

category 6 (Cat 6 - cable standard for Gigabit Ethernet and other interconnects that is backward compatible with Category 5 cable, Cat-5e, and Cat-3. Cat-6 features more stringent specifications for crosstalk and system noise. (Part of the EIA/TIA 568A standard.)

CATV - Community Antenna Television system. Broadcast signals are received by a centrally located antenna and distributed by cable through a region.

CEC - Consumer Electronics Control provides a limited amount of device-to-device control (e.g., by powering up a Blu-ray player, automatically changes the HDMI input on the connected television)

charged-coupled device (CCD) - a semiconductor image-sensing device, commonly used in video and digital cameras, which converts optical images into electronic signals.

Channel 38 - A frequency band that radio microphones can operate in (606 MHz - 614 MHz). Normally a license is required in the UK from JFMG to operate in this band.

Chrominance - Signal used in video systems to convey the color information of the picture.

clock adjustment - also called timing signals, used to fine-tune the computer image. This function adjusts the clock frequencies that eliminate the vertical banding (lines) in the image.

closed circuit television (CCTV) - a system of transmitting video signals from the point of origin to single or multiple points equipped to receive signals.

coaxial cable - a cable consisting of a center conductor surrounded by insulating material, a concentric outer conductor, and optional protective covering, all of the circular cross-section. Abbreviated coax.

CODEC - an acronym for coder/decoder. An electronic device that converts analog signals, such as video and audio signals, into digital form and compresses them to conserve bandwidth on a transmission path.

color burst - that part of an NTSC video signal that carries the color information. It is a signal consisting of several (8 to 10 in NTSC) cycles of unmodulated color subcarriers, superimposed at a specified location within the composite signal.

color difference signals - signals which convey color information such as hue and saturation in a composite format. Two such signals are needed. These color difference signals are R-Y and B-Y, sometimes referred to as Pr and Pb or Cr and Cb.

comb filter - transversal filter that combs out a specific set of frequencies. Comb filters are very effective in separating the chrominance and luminance sidebands in an NTSC video signal.

combiner - in a process called multiplexing, the combiner puts signals together onto one cable constituting a broadband signal.

common-mode - refers to either noise or surge voltage disturbances occurring between the power neutral (white wire) and the grounding conductor (green wire). Unwanted common mode disturbances exist as a result of noise injection into the neutral or grounding wires, wiring faults, or overloaded power circuits.

common-mode rejection ratio (CMRR) - The ratio of the common-mode interference voltage at the input of a circuit, to the corresponding interference voltage at the output.

component video - color video in which the brightness (luminance) and color hue and saturation (chrominance) are handled independently. The red, green and blue or, more commonly, the Y, R-Y, and B-Y signals are encoded onto three wires. Because these signals are independent, processing such as chroma keying is facilitated.

composite video signal - the electrical signal that represents complete color picture information and all synchronization signals, including blanking and the deflection synchronization signals to which the color synchronization signal is added in the appropriate time relationship.

compression - the action of the air molecules moving closer together permitting audible sound.

compressor - a compressor controls the overall amplitude of a signal by reducing that part of the signal which exceeds an adjustable level (threshold) set by the user. When the signal exceeds the threshold level, the overall amplitude is reduced by a ratio, also usually adjustable by the user.

condenser microphones - also called a capacitor microphone, it transduces sound into electricity using electrostatic principles.

conductor - in electronics, a material that easily conducts an electric current because some electrons in the material are free to move.

cone - most commonly used component in a loudspeaker system and found in all ranges of drivers.

conferencing systems - the technology by which people separated by distance come together to share information. Conferencing systems may include projection, monitor displays, computers, satellite connections video and audio playback devices, and much more.

continuity - the quality of being continuous (as in a continuous electrical circuit).

control track - the portion along a length of a recorded tape on which sync control information is placed; used to control the recording and playback of the signal.

CPU - (central processing unit); the portion of a computer system that reads and executes commands.

crosstalk - any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates an undesired effect in another circuit or channel.

CRT - Cathode Ray Tube; the video display tube used in monitors and receivers, radar displays, and video computer displays. The CRT is a high-vacuum tube containing an electron gun to produce the images seen on the face of the tube.

current - the amount of electrical energy that is flowing in a circuit.

curvature of field - a blurry appearance around the edge of an otherwise in-focus object (or the reverse) when the velocity of light going through the lens is different at the edges than at the center of the surface, due to the lens design.

Coaxial Digital Audio - Coaxial digital cables are the most common type of connection cable used for digital audio. They look like the RCA cables that many people use and are familiar with. The only difference is that it carries digital instead of analog signals.

Component Video - Video signal is separated into its component form i.e., red, green (sync), and blue, and referred to as YUV. (Also see YPbPr and YCbCr). Component Video signal is the same as YUV where Y = luminance Pb = blue minus luminance and PR = red minus luminance.

Composite Video - The composite video signal is where the luminance and chrominance are mixed with sink information down a single cable.

DAC (D/A converter) - An IC Chip that converts digital signals into analog.

D-sub connector - a generic name for D-shaped serial connectors used in data communications.

dBSPL - a measure of sound pressure level measured in dynes per centimeter squared. Its reference, 0 dBSPL equals 0.0002 dynes/cm2. dBSPL is used as a measure of acoustical sound pressure levels and is a 20log function.

decibel - a comparison of two measurements or values. Abbreviated dB, it is one-tenth of a Bel (a unit of measurement named for Alexander Graham Bell).

deflection coil - a uniform winding of wire used to electromagnetically direct an electron beam to draw an image on a cathode ray tube (CRT).

delay - an audio signal processing device or circuit used to retard the speed of transmission on one or more audio signals or frequencies.

demodulator - electronic device that removes information from a modulated signal.

depth-of-field - the area in front of a camera lens that is in focus from the closest item to the camera to the furthest away.

Deep Color - Term used to describe a gamut (color space) comprising a billion or more colors. The HDMI 1.3 specification supports Deep Color bit depths. It defines bit depths for Deep Color as 30 (10) bits (1.073 billion colors), 36 (12) bits (68.71 billion colors), and 48 (16) bits (281.5 trillion colors).

De-interlaced Video - A video image is made up of a series of still images played in rapid succession, this is divided into a series of scan lines drawn on the display, de-interlaced video draws all these scan lines in one pass.

Display Port - Digital interface transmitting HD video, audio, and data signals.

differential-mode - refers to either noise or surge voltage disturbances occurring between the power hot and the neutral conductor. Most differential mode disturbances result from load switching within a building, with motor-type loads being the biggest contributor.

diffusion - the scattering or random redistribution of a sound wave from a surface. It occurs when surfaces are at least as long as the sound wavelengths, but not more than four times as long.

digital - a method of transmitting information by discrete, non-continuous impulses.

digital-to-analog converter - an electronic device that converts digital signals into analog form.

D-ILA - Digital Direct Drive Image Light Amplification projectors.

DIN connector - Deutsche Industrie-Norm (DIN) – a connector that follows the German standard for electronic connections.

direct current (DC) - electricity that maintains a steady flow and does not reverse direction, unlike alternating current (AC). Usually provided by batteries, AC to DC transformers, and power supplies.

direct sound - also known as near-field, it is sound that is not colored by room reflections.

dispersion - can be seen when a white light beam passes through a triangular prism. The different wavelengths of light refract at different angles, dispersing the light into its individual components.

distributed sound - a sound system in multiple loudspeakers separated by distance and typically operates at a lower sound pressure level than a high-pressure system. The loudspeakers are most often suspended over the heads of the listeners.

distribution amplifier - an active device used to split one input into multiple outputs while keeping each output isolated, and the signal level constant.

DLP - Digital Light Processing(c) by Texas Instruments. A projection system that has technology based on the Digital Micromirror Device (DMD). It uses thousands of microscopic mirrors on a chip focused through an optical system to display images on screen.

document camera - an imaging device used to create a video image of printed documents or three-dimensional objects.

dome - used in all ranges of drivers.

driver - in audio, an individual speaker unit.

DTV - Digital Television; a signal transmitted digitally.

DVD - Digital Video Disc or Digital Versatile Disc; an optical storage medium for data or video.

DVI - Digital Visual Interface; a connection method from a source (typically a computer) and a display device that can allow for direct digital transfer of data. The digital signal is limited to 5 meters.

DVI-D - one of two common multi-pin connectors available for DVI signals. The DVI-D carries no analog video information, only digital. The digital signal is limited to 5 meters.

DVI-I - one of two common multi-pin connectors available for DVI signals. The DVI-I adds analog video to the connection, permitting greater distances than the digital limit of 5 meters.

dynamic microphone - a pressure-sensitive microphone of moving coil design that transduces sound into electricity using electromagnetic principles.

Dolby TrueHD - Dolby TrueHD is an advanced lossless multi-channel audio codec developed by Dolby Laboratories which is intended primarily for high-definition home-entertainment equipment such as Blu-ray discs.

Dolby Digital Plus (DD+) - A digital audio compression format developed from the earlier Dolby Digital, increasing quality, and available Channels.

DTS-HD Master Audio - Lossless audio codec created by Digital Theater Systems developed from the earlier DTS with increased sampling frequency and bit rate.

Dynamic Range - Dynamic range describes the ratio of the quietest sound to the loudest sound in a musical instrument or piece of electronic equipment.

Downscaling - Reduction of a video signal from one size (resolution) to another.

DVI - Digital Video Interface is a video interface standard designed to provide extremely high visual quality on digital display devices such as flat panel LCD displays and digital projectors.

Digital Noise Reduction - Eliminates unwanted color noise from the video signal for smoother image reproduction.

early reflected sound - created by sound waves which are reflected (bounced) off surfaces between the source and the listener. The sound waves arrive at the listener’s ear closely on the heels of the direct sound wave.

echo cancellation - a means of eliminating echo from an audio path.

EDID - Extended Display Identification Data ('EDID' for short) is a data command structure provided from a digital display (i.e., Screen, TV, or projector) that communicates its capabilities to the AV system. EDID data typically includes manufacturer name, model and serial number, display size, resolution, luminance information, etc.

EIA - Electronics Industries Alliance. The association which determines recommended audio and video standards in the United States.

electromagnetic interference (EMI) - an electrical disturbance caused by an electromagnetic field, either low frequency or radio frequency (RF).

EMI - (See electromagnetic interference.)

emissive technology - any display device that emits light to create an image.

encoded - a signal that has been compressed into another form to reduce size or complexity, as in a composite video signal.

equalizer - electronic equipment that adjusts or corrects the frequency characteristics of a signal.

EN54 - a mandatory standard that specifies the requirements and test procedure for every component of a fire alarm and detection system.

equipment rack - a centralized housing unit that protects and organizes electronic equipment.

Ethernet - A PC interface used to connect computers and peripherals in a Local Area Network (LAN).

expander - an audio processor that comes in two types: a downward expander and a part of a commander.

Feedback - Microphone Feedback (also known as the 'Larson Effect') is the disturbing howl/squeal/buzz noise created when a microphone and loudspeaker negatively affect one another. Feedback occurs when sound from loudspeakers is picked up by the microphone, re-amplified and picked-up again from the speakers. This continuous loop results in the howl or rumble of the feedback effect.

Frequency Response - Describes the general output frequency range of a device/amplifier.

Full HD - 1920 x 1080p (progressive) video resolution.

HD - High Definition.

HD Ready - TVs that can display High-Definition content in both 720p and 1080i formats as a minimum standard.

HDD - Hard disk drive.

HDTV - High-definition television.

HDBaseT - Transmits converged uncompressed full HD digital video, audio, one hundred BaseT Ethernet, Power-over-Ethernet (PoE), and various control signals through a single Cat5e/6/7 cable over a distance of up to one hundred metros. Utilizing its full features is known as HDBaseT '5Play'.

HDBaseT Lite - Reduced function, lower cost version of HDBaseT; this 3Play 'Lite’ version transmits HD video, audio, and control signals through a single Cat5e/6/7 cable over a distance of up to sixty metros.

HDMI - Stands for High-Definition Multimedia Interface and provides an easy and convenient way of connecting digital audio-video components.

HDMI v1.x - Different HDMI specifications released by HDMI LLC.

HDMI 2.0/2.0a - With HDMI 2.0, among the many new features the increase in data speed from 10.2 to 18 Gbit/s is by far the most important. This increase in speed allows HDMI 2.0 to carry 4K resolution at 60 frames per second. Other features of HDMI 2.0 include; up to 32 audio channels for a multi-dimensional immersive audio experience, up to 1536kHz audio sample frequency for the highest audio fidelity, simultaneous delivery of dual video streams to multiple users on the same screen, simultaneous delivery of multi-stream audio to multiple users (up to 4), support for the wide angle theatrical 21:9 video aspect ratio, dynamic synchronization of video and audio streams, CEC extensions provides expanded command and control of consumer electronics devices through a single control point. Support for BT.2020 Colorimetry with ten or more bits of cooler depth. The latest revision HDMI 2.0a, adds support for High Dynamic Range (HDR). HDR for TVs promises more realistic video with brighter bright and darker dark. This technology comes under various guises and names depending on the manufacturer

HDMI over IP - HDMI over IP technology converts HDMI signals to TCP/IP packets and delivers them across a network utilizing the same CAT wiring that is already in place for standard IP Networks such as Ethernet. By using H.264 compression technology (as used by Blu-ray and Netflix) HDMI over IP allows you to send signals up to 4K over standard gigabit LAN networks including Ethernet switches. Although H.264 is not lossless compression in the strict mathematical sense, the amount of loss is typically imperceptible. The latency of H.264 is ultra-low with the signal delay down to an unnoticeable two or three frames per second.

HDCP - Stands for High-bandwidth Digital Content Protection. It is a copy-protection scheme developed by Intel to be used in conjunction with DVI and HDMI connections.

HDCP 2.2 - The latest version of the High-bandwidth Digital Content Protection protocol specifically developed to support 4K UHD content.

Induction loop System - An Induction loop System (also known as an Audio Frequency Induction Loop, AFILS, or Hearing Loop) is an assistive hearing system providing access to sound distribution for those wearing a hearing aid. Often integrated into a standard 100v Line PA System.

Ingress Protection - Also known as I.P. Rating, Ingress Protection is the characteristic of a product in terms of its resistance to the penetration of solid objects and liquids. Indicated by the letters IP (International Protection) followed by two numbers: the first number = protection against solid object ingress, the second being protection against liquid ingress. Often related to outdoor or harsh environment products such as loudspeakers and surveillance cameras.

Interlaced Video - A video image is made up of a series of still images played in rapid succession; this is divided into a series of scan lines drawn on the display. The interlaced video draws all these scan lines in two passes.

IP - Internet protocol.

I.P. Rating - See Ingress Protection.

IR - Infrared, commonly used as a wireless line of sight control for AV equipment.

JPEG - JPEG stands for Joint Photographic Experts Group, a consortium that has developed and spread this format worldwide. It is a compression format that efficiently stores digital images.

KSV - Key Selection Vector. A unique numerical key in HDCP content protection.

LCD - Liquid Crystal Display, a high-quality LCD display that gives a clearer picture with excellent color, contrast, and detail, also used with some projectors.

LED - Light-emitting Diode, a semiconductor device that emits visible light when an electric current passes through it.

Low Impedance - Also referred to as Low Z - the resistance of a loudspeaker or load capability of an amplifier, usually expressed in Ohms. Typical impedance levels are 4ohm, 8ohm, or 16ohm. Low Z systems are typically used in high-power music reproduction systems.

Low Z - See Low Impedance

LPCM - Linear Pulse Code Modulation is an uncompressed audio technology. Instead of compressing sound data, it simply stores the information as it is, giving you an exact copy of the original. Various bit and sampling rates can be used.

Luminance - This is the signal used in video systems to convey the light information of the picture.

MPEG4 - Stands for Motion Picture Experts Group and represents a family of digital audio and video coding standards. MPEG4 has a high compression ratio, which creates a small file size that is suitable for personal computers and Internet applications.

Motion Adaptive Field Noise Reduction - This new noise-reduction technology reduces background noise.

NFC / Near Field Communication - Advanced NFC (Near Field Communication) technology allows 2-way wireless communication between electronic devices. The devices communicate over a short distance (usually up to a maximum of 4 cm), and it is precisely this noticeably short range that ensures the security of this technology.

An employee/user can use their NFC - enabled smartphone to gain secure access to a building by placing it near a suitable access unit. NFC technology can be used as an alternative to an RFID card/pass system.

NTSC - In the US and Japan, NTSC (National Standards Television Committee) is the standard used for all video equipment. NTSC uses 525 lines to make up a TV picture and scans at 60 Hz.

OSD - On-Screen Display.

Optical Digital Audio - Optical digital cables use the Toslink connector, these use pulses of light to transmit digital audio data. Optical uses light thus it is immune to interference from electromagnetic and radio frequencies.

PA (Public Address) - Public Address / Public Address System. An electronic audio amplification system (usually for voice and background music), including amplification, loudspeakers, and sound source (microphone, music source, etc.).

PAL - Phase Alternation Line, this is the video standard used most in Europe. PAL uses 625 lines to make up a TV picture and scans at 50Hz.

Passive - A passive speaker does not have a built-in amplifier; it needs to be connected to an amplifier to provide the current to make it work.

PCM - Pulse Code Modulation, digital bitstream audio format commonly supporting sixteen bits up to 48kHz sampling frequency in stereo.

Phantom Power - A DC power source used for providing voltage to operate microphones that contain active electronic circuitry such as condenser/electret types down the microphone cable line. Usually provided by the source equipment (Mixer Desk/Preamp/Amplifier) various voltage options are available between 3~52v DC. Separate Phantom Power PSU devices are also available.

Pixel - Short for Picture Element, Pixels are the tiny dots of information that make up a digital image. The more pixels there are on the camera's image sensor (CCD or CMOS) or display, the higher the image resolution will be.

PoC / Power over Cable - Like PoE (or Power over Ethernet), PoC / Power over Cable allows for both data and power to be sent simultaneously over the cable (usually Cat5e/Cat6).

Frequently utilized in HDBaseT and HDMI - over-Cat cable systems, PoC will send power from the Transmitter / Splitter / Matrix to power the Receiver at the remote end of the connection, negating the need for a mains power supply at the Receiver.

PoE / Power over Ethernet - Power over Ethernet – also known as PoE – describes systems that allow for power and data to be simultaneously sent over the same data / Ethernet cable, with the power being supplied by an Ethernet Router or Switch. PoE is often used to supply power at the remote end of a transmission over a Cat cable system (such as IP cameras, IP telephones, etc.) where local power may not be available or where reduced cable connectivity is beneficial to the installation.

Powered - Powered speakers, also known as self-powered speakers or active speakers have built-in amplifiers. They can be connected directly to an audio source, such as a Mixer/ Pre-Amp or Music Player without the need for an external amplifier.

Progressive Scan - A sales term for describing de-interlaced video.

PVR - Personal Video Recorder, a device that records video without videotapes or discs.

Pass Through - Video by-pass output, outputs an additional copy of the original input signal.

Receiver (RX) - Receives AV signals through various interconnects after being sent by a compatible transmitter.

RCA - Recording Company of America, RCA (or Phono) is the standard way of connecting audio and video components.

RGB - Stands for red, green, and blue. A video connector or lead that offers RGB output carries these primary colors separately for greater picture quality.

RJ45 - The RJ45 is a connector used on CAT cabling for connecting computers and other devices to local area networks (LANs).

RMS - 'Root Mean Squared' - the formula used to calculate an approximate average of the power an amplifier can continuously create, and a speaker receives.

RS-232 - Is a voltage loop interface for two-way (full-duplex) communication.

Resolution - The number of pixels in an image. The higher the resolution, the more detailed the picture will be.

SIP - SIP-which stands for 'Session Initiation Protocol'-is a standard protocol to establish, modify or terminate multimedia sessions (video, voice, chat, gaming, and virtual reality) or internet telephony calls. It is mostly used in internet telephony for voice and video calls over Internet Protocol (IP) networks, as well as audio multicast meetings and instant messaging conferences. In the world of VoIP, SIP, as the name suggests, is a call setup protocol (as opposed to a 'data transfer' protocol) and is needed in a voice call, for example, to get two telephones talking. SIP can run over IPv4 and IPv6 and it can use either TCP or UDP.

S-Video - A high-quality video connection that offers better picture quality than standard composite video. S-Video cables have round, mini four-pin plugs, and sockets.

Sampling Rate - Sampling is the process of converting the heights of a sound wave (analog signal) taken and converted at set periods into digits (digital encoding). The sampling frequency is the number of samples taken per second, so larger numbers mean a more faithful reproduction of the original sound.

SCART - An audio/video connector to carry the audio & video signals on one convenient cable.

SD - Standard Definition, traditional format used for TV made up of 576 (visible) Horizontal lines (PAL).

Stereo - Stereophonic sound, commonly called stereo, is the reproduction of sound using two or more independent audio Channels through a symmetrical configuration of loudspeakers in such a way as to create the impression of sound heard from various directions, as in natural hearing.

TBC - Time Base Corrector, ensures optimum playback picture quality even in freeze frames or slow motion and compensates for any irregular movement of the tape transport mechanism.

Transmitter - Transmits AV signal through various interconnects and is accepted by a compatible receiver.

UHD - Ultra HD or Ultra High-Definition consumer display format with a resolution of 3840 x 2160. It is increasingly referred to as '4K UHD'. A UHD display will deliver four times as much detail as the Full HD (1080p) displays we are so familiar with, with around eight million pixels per screen. This technology is also starting to feature in cameras, smartphones, and tablets, as well as computer monitors and PC games.

USB - Universal Serial Bus. A connection port for transferring digital data, used on PCs.

USB 3.1 - The latest revision of USB utilizes a new transfer technology called 'Superspeed Plus which as the name suggests significantly increases data transfer speeds compared with the previous USB 2.0 and 3.0. With a huge boost in bandwidth, USB 3.1 Superspeed Plus delivers an incredible 10 Gbps data transfer speed. USB 3.1 also supports 'Quick Charge' - delivering a massive one hundred Watts of power!

USB Type C - The latest USB connector - Type C is smaller than previous versions, rotatable (you will not have the annoyance of trying to plug in a connector 'the wrong way up'), and features the new, increased ion configuration to support full USB version 3.1.

Upscaling - Conversion of a video signal from one size (resolution) to another, upscales increase the resolution.

Voice over IP (VoIP) - is a category of hardware and software used to manage the delivery of voice information over Internet Protocol (IP) networks, such as the internet, and involves sending voice information in digital form in discrete packets. The main advantages of VoIP over traditional telephony are its inexpensive implementation costs and its versatility. That said, there is a greater likelihood of dropped calls and degraded voice quality when the underlying network is heavily used. Other terms commonly associated with VoIP are IP telephony, Internet telephony, broadband telephony, and broadband phone service.

Widescreen - - Screen display ratio providing a greater width-to-height ratio. The 'standard' widescreen ratio is 16:9 (compared with the traditional TV ratio of 4:3).

Wireless - Devices that are Wi-Fi or Wireless enabled can connect to a local area network and send/receive data without the need for a physical (wired) connection.

Wireless Inductive Charging - Set to be one of the next key must-have functions in smartphones and handheld devices, wireless inductive charging allows for connector / cable-free charging of battery-powered devices.

xvYCC - Extended gamut YCC (also called x.v. Color) is a color space that can be used in the video electronics of television sets to support a gamut 1.8 times larger than that of standard sRGB color space.

YPbPr - Refers to Component video (YUV) at a higher resolution than standard definition.

Secam - color-television broadcasting system used in France