The following glossary is a list of some of the more common terms used when it comes to Hi-Fi and smart home technology.
We hope you find it useful to help simplify the sometimes bewildering array of such terms.

Certainly, all these different terms might sound like something otherworldly from a magical forest. Terms and concepts can often have different meanings or connotations in different contexts. By taking the time to define key terms and concepts at the beginning of a study, it can help to ensure that everyone is on the same page and that there is a common understanding of the language used in the subject matter. It can help avoid confusion and misunderstanding, allow better communication and make the learning process more efficient. It also will allow you to ask more precise and targeted questions when you need further clarification.

Of course, should you prefer, we always welcome your call or your visit to our office where one of our specialists can help you choose the right elements for your home or project – without baffling you with jargon.

• AMPLIFIER (aka “Amp”): An electronic device that increases the strength of an audio signal. Take a look at popular amplifiers here.
• ACOUSTIC SUSPENSION: A type of loudspeaker design that uses a sealed enclosure to achieve a flatter frequency response and a higher sensitivity.
• AMPLITUDE: The strength or intensity of an audio signal.
• ANALOG TAPE: A type of recording medium that uses magnetic tape to store analog audio signals.
• ANALOG: A type of audio signal that is continuous and varies in level, as opposed to a digital audio signal which consists of discrete numerical values.
• ADC (Analog-to-Digital Converter): An electronic device that converts an analog audio signal into a digital signal.
• A/B switching: A method of comparing two audio signals by switching between them quickly.
• BASS: The lower frequencies of an audio signal, typically those below around 250 Hz.
• BIT DEPTH: The number of bits used to represent the amplitude of a digital audio sample. Higher bit depths result in a higher resolution and a greater dynamic range.
• BIT RATE: The number of bits per second used to represent a digital audio signal. Higher bit rates result in higher audio quality, but also larger file sizes.
• BALANCED AUDIO: An audio signal that uses three wires (positive, negative, and ground) to reduce noise and interference.
• COMPRESSION: The process of reducing the dynamic range of an audio signal in order to make it easier to transmit or store.
• COMPRESSOR: An electronic device or software that reduces the dynamic range of an audio signal by automatically reducing the level of loud sounds and increasing the level of quiet sounds.
• DAMPING FACTOR: A measure of the ability of an amplifier to control the motion of a loudspeaker.
• DISTORTION: The alteration of an audio signal from its original form, resulting in a degradation of sound quality.
• CROSSOVER: An electronic circuit that divides an audio signal into separate frequency bands, which are then sent to different loudspeakers or drivers.
• CD (COMPACT DISC): A type of optical disc used to store digital audio.
• DIGITAL AUDIO: Audio that has been converted into a digital format, typically using pulse-code modulation (PCM).
• DYNAMIC RANGE: The difference in decibels between the loudest and softest parts of an audio signal.
• DYNAMIC MICROPHONE: A type of microphone that uses a moving coil and magnet to convert sound waves into an electrical audio signal.
• DAC (DIGITAL-TO-ANALOG CONVERTER): An electronic device that converts a digital audio signal into an analog signal that can be played through an amplifier and loudspeakers.
• EQUALIZATION: The process of adjusting the frequency response of an audio signal by boosting or cutting certain frequencies.
• EQUALIZER: An electronic device or software that allows the user to adjust the frequency response of an audio signal by boosting or cutting certain frequencies.
• FREQUENCY: The number of cycles per second of an audio signal, measured in hertz (Hz). 
• FREQUENCY RESPONSe: The range of frequencies that an audio system is capable of reproducing.
• FADER: A control on a mixing console that allows the user to adjust the level of an audio signal.
• Hi-Fi: Short for “High-Fidelity”. Hi-Fi refers to audio equipment that is designed to reproduce sound with a high degree of accuracy and detail.
• HEADPHONE AMPLIFIER: An amplifier that is specifically designed to drive headphones.
• HEADROOM: The difference between the maximum level of an audio signal and the level at which distortion occurs.
• IMPEDANCE: The resistance of an electrical circuit to the flow of an alternating current. In the context of audio systems, it refers to the resistance of a loudspeaker or other component to the flow of an audio signal.
• LOUDSPEAKER: A device that converts an electrical audio signal into sound waves that can be heard by the listener.
• LOUDSPEAKER DRIVER: A component of a loudspeaker that converts the electrical audio signal into sound waves. Common types of drivers include woofers, tweeters, and midranges.
• LIMITER: An electronic device or software that prevents the level of an audio signal from crossing a certain level.
• PREAMPLIFIER: An electronic device that prepares an audio signal for amplification by an amplifier.
• TURNTABLE: A device that plays vinyl records by rotating them at a constant speed and using a stylus to track the grooves in the record. Here you can see what the turntables look like.
• THD (Total Harmonic Distortion): A measure of the amount of distortion present in an audio signal, expressed as a percentage.
• TREBLE: The higher frequencies of an audio signal, typically those above around 4 kHz.
• MIDRANGE: The frequencies of an audio signal that fall between the bass and treble ranges, typically between around 250 Hz and 4 kHz.
• MP3 (MPEG Audio Layer 3): A type of digital audio encoding format that uses lossy data compression to reduce the size of audio files.
• NOISE FLOOR: The level of background noise present in an audio system.
• VINYL: A type of record made of a thin, flexible plastic material that is played on a turntable.
• SPEAKER SPECIFICATION: We already work with some of the world’s finest names in speaker technology. If you have a personal preference, our independence means we’re able to accommodate it.
• MULTI-ROOM MUSIC: Wireless systems such as those from Sonos and Bluesound make it simpler than ever to create a multiroom setup, with music stored centrally or streamed from the cloud and the ability to have different playlists in each room or the same in multiple rooms.
• APP-CONTROLLED MUSIC: How you manage your sound system is up to you, with the option of simple touchpads, your phone, physical buttons or voice control.
• TV INSTALLATION: From simple one-box solutions to full home theatre systems, we’re able to install any size TV so that it discreetly complements your room, rather than dominates ii.
• HD DISTRIBUTION: Your Sky or Virgin boxes, along with other video devices can be centrally located and the signal distributed to all the TVs in your home at full high-resolution definition. This eliminates the ugly spaghetti of cables typically seen underneath or near TVs.
• TV CONTROL: Eliminate multiple, and confusing, remote controls. We can ensure easy and reliable control from a single remote (of which you can have more than one if you suffer from “remote battles” within your family).
• CINEMA DESIGN: Our experts will take into account every aspect of the design, from the technology to the surrounding materials, to make sure you get the ultimate home movie experience.
• CINEMA INSTALLATION: We’ll project manage the project from start to finish, coordinating every aspect and minimising the inconvenience. We can provide acoustic treatment design and installation and ensure it is sympathetic to your interior design objectives.
• DOLBY SOUND INSTALLATIONS: A totally immersive cinematic sound system, revolutionary 3D sound formats place every element of the movie’s soundtrack carefully in the space around you, taking into account your room. We can advise on which experience fits your desires and budget.
• DATA NETWORK SOLUTIONS: We can install cable infrastructures to create a complete network for both wireless and wired technology, giving you the most reliable and efficient wireless roaming and data access.
• WI-FI INSTALLATION: Ensuring thorough and reliable wi-fi coverage is managed by our specialists, with much of the programming and setup carried out off-site to minimise disruption.
• REMOTE, PRO-ACTIVE, MAINTENANCE: There is little guaranteed to wind us up more than our wifi/internet going down these days. That’s why (only with your permission) we will implement a remote management process on our servers that alerts us immediately when issues arise. Often we have fixed problems before you know one exists, leaving you blissfully unware and, more importantly, connected.
• DESIGN & SECURITY: If the worst happens and your network is down, our systems are designed to not leave you high and dry. Security is paramount and so we implement secure and/or guest access to your precious home network.
• HEATING CONTROLS: A variety of controls are now on the market. We can make sure you have the most suitable option for your system and, as required, integrate such controls into your home system or, if preferred, leave them operating standalone.
• APP CONTROLLED HEATING: Intuitive, easy to use and very convenient, we can enable full control from your tablet, smartphone or dedicated in-home controller.
• TOUCH SCREEN SYSTEMS: The simplest way to control your heating and air conditioning within the home is to use an intuitive touch-screen system, easy enough for the whole family to use.
• ENERGY MANAGEMENT SYSTEMS: Modern systems do more than just control warmth. Nowadays they can monitor your energy usage and learn to adjust the heating or air conditioning based on the utilisation of the rooms in use. This can significantly reduce wasted energy.
• ALARMS: There is a wide range of alarm systems that can be tailored to suit any size or type of property, and can incorporate access systems, CCTV and smoke, heat and carbon monoxide detectors.
• APP CONTROLLED ALARMS: Wired or wireless, alarms can be fully integrated into other software – so they can all be fully controlled from one simple app alongside your lights, alarm and CCTV, if required.
• CCTV SYSTEMS: Sophisticated CCTV systems can be incorporated into your alarm system or installed standalone. These can record any movement and be accessible via your home display screens or across the internet from anywhere in the world.
• DOOR ENTRY: Be able to communicate with visitors to your home from wherever you are in the world and, if you so choose, permit them entry or give them instructions, for example, on where to leave their delivery.
• 1080P / 1080i: There are two main types of high-definition (HD) picture: 1080i and 1080p. HD TV is broadcast in 1080i, while high-definition Blu-ray discs are recorded in 1080p, which is marginally more detailed and realistic. This is because on 1080p, the 1,080 horizontal lines are scanned progressively, or one after another. With 1080i, even lines then odd lines are scanned alternately to make up the picture, although the difference is really quite subtle.
• 4K/Ultra HD 4K TVs – also referred to as ultra-HD or UHD – have four times the pixels of ‘normal’ HD 1080p TVs. Most of the TVs released are now 4K and they usually have screens 40-inches or over, as you need a larger display to really appreciate the extra detail in the picture. To watch 4K content you’ll need to subscribe to Netflix or Amazon Video, or invest in a 4K Blu-ray player and some movies. Eventually, we’ll see some 4K TV channels launch, too. For more on 4K, please see our What is 4K TV? guide.
• ACCESS POINT: In computer networking, a wireless access point (WAP), or more generally just an access point (AP), is a networking hardware device that allows a Wi-Fi device to connect to a wired network. The AP usually connects to a router (via a wired network) as a standalone device, but it can also be an integral component of the router itself. An AP is differentiated from a hotspot, which is the physical location where Wi-Fi access to a WLAN is available. Multiple APs may be used to provide complete coverage of a property.
• AMAZON ECHO (ALEXA): Alexa is a virtual assistant developed by Amazon. It is capable of voice interaction, music playback, making to-do lists, setting alarms, streaming podcasts, playing audiobooks, and providing weather, traffic, and other real-time information, such as news. Alexa can also be used to control other devices or home automation systems. Users can extend the Alexa capabilities by installing “skills” (additional functionality developed by third-party vendors, in other settings more commonly called apps).
• ARCHITECTURAL AUDIO: The term used to describe loudspeakers, amplifiers and subwoofers designed to match your décor.
• ARCHITECTURAL SPEAKERS: Hi-fidelity audio speakers are designed to blend unobtrusively into the fabric of your home, Examples include ceiling speakers, in-wall speakers, on-wall speakers, garden speakers.
• AUDIO INTERCONNECT: A cable used to transfer analog or digital signals from an audio source to an amplifier or powered speaker.
• BANDWIDTH: Since the popularisation of the internet, the term bandwidth has generally referred to the volume of information per unit of time that a transmission medium (like an internet connection) can handle. An internet connection with a larger bandwidth can move a set amount of data (say, a video file) much faster than an internet connection with a lower bandwidth. Bandwidth is typically expressed in bits per second, like 60 Mbps or 60 Mb/s, to explain a data transfer rate of 60 million bits (megabits) every second.
• BLUCUBE: BluCube is a brand whose range includes architectural speaker solutions, amplifiers and accessories for music systems. BluCube claim to offer outstanding price-performance products when compared to other brands.
• BLUESOUND: A multi-room audio system from NAD Electronics that unifies all the user’s local and Internet-based music sources and delivers them to wireless speakers throughout the home over Wi-Fi. Control is via the BluOS app in a PC, Mac, iOS or Android device. BLUESOUND NODE2 can integrate an existing stereo, home theatre or ordinary speakers into the BluOS wireless system. Bluesound uniquely focus on delivering High-resolution audio and compete with alternative offerings based on their NAD electronics pedigree of sound reproduction.
• BLUETOOTH: The standard wireless network for short-range transmission of digital audio and data. Using radio waves, Bluetooth transmits through walls and other non-metal barriers. Although the term is synonymous with cellphone headsets and hands-free telephony in vehicles, Bluetooth is also used for wireless speakers, keyboards, mice, game controllers, smartwatches and more.
• BluOS (see BLUESOUND): BluOS is the audio operating system that enables the Bluesound High-Res multi-room system. BluOs is also the name of the app used to control the system.
• Cat5/Cat6: Alternatively referred to as an Ethernet cable, a CAT5 or Category 5 is a description of networkcabling that consists of four twisted pairs of copper wire terminated by an RJ-45 connector. Cat5 has a maximum length of 100m, exceeding this length without the aid of bridge or other network device could cause network issues. Like virtually everything else in the technology sector, these cables have undergone significant development over the years, and the newest cables are capable of significantly greater performance than previous cables. The difference between a Cat5 vs Cat6 cable is not only higher speeds but reduced “crosstalk”.
• CCTV 4CCTV (CLOSED-CIRCUIT TELEVISION): this is a TV system in which signals are not publicly distributed but are monitored, primarily for surveillance and security purposes. CCTV relies on strategic placement of cameras, and observation of the camera’s input on monitors somewhere.
• CEILING SPEAKER: A loudspeaker that is fitted into an aperture in a ceiling and which uses the ceiling void as the back box of the speaker. Typically used to provide an even dispersion of sound and where audio performance is required without intrusion.
• CINEMA ROOM: Cinema rooms mean different things to different people. From a multi-purpose room with a cinema sound system to a bespoke, dedicated full-on theatre experience with Atmos or THX sumptuous seating and acoustic treatment.
• CLOUD: In the context of audio-systems, cloud refers to the internet and services accessible from the internet such as music from Spitify, Tidal or Deezer; video content from Netflix or Alexa from Amazon.
• CODEC CODER-DECODER: A device or program that compresses data to enable faster transmission and which also decompresses received data. Compressed files can be transmitted faster and stored in less space. For example, a song on a CD can be reduced to 10% of its original file size using MP3 compression.
• CONTROL – IP: IP (Internet Protocol) control refers to the ability to sent controling messages to devices addressed via Internet Protocol or IP addressed devices.
• CONTROL – IR: IR (Infra-Red) control refers to devices controlled by infra-red signals such as your TV or satellite devices. IR control requires line of sight or, for devices located out of sight, IR transmitter-receivers.
• CONTROL – RS232: RS-232 is a standard communication protocol for linking devices to allow serial data exchange. In simple terms RS232 defines the voltage for the path used for data exchange between the devices. RS232 is a reliable means of controlling devices and frequently used in automated systems.
• CONTROL Voice Demand for and reliability of voice control continues to improve. Ultimately this will lead to the ability to control functions through natural speech.
• CONTROL 4: Control 4 is a brand and manufacturer of smart home systems. From lighting control to audio-visual systems, security, comfort, Contol 4 can be retrofitted or integrated at the build phase of a project and provides a powerful means of bringing the different elements together to enable smart home function.
• CROSSOVER: A speaker crossover is an electronic device that takes a single input signal and creates two or three output signals consisting of separated bands of high-, mid-, and low-range frequencies. The different bands of frequencies feed the different speakers, or “drivers,” in a sound system: tweeters, woofers, and subwoofers. Without a crossover, a messy, sonic “traffic jam” results. Your midrange and sub would duplicate too many of the same frequencies and your sub would waste time trying to play high notes it wasn’t meant to handle. A “fatal pile-up” could also occur, with your tweeters being destroyed by some renegade tractor-trailer of a bass note thumping along in the wrong audio lane.
• CROSSTALK ELECTRONIC EQUIPMENT (including cat/ethernet cables) emit electromagnetic signals. When lots of cables are near one another, these cables can interfere with one another. This interference is referred to as “crosstalk”. Crosstalk increases errors and lost packets (among other issues). Newer versions of cat cables (i.e. Cat6 cables) reduce the impact of crosstalk through a variety of methods, including improved shielding and twisted cable design.
• DAB: DAB, or digital audio broadcasting, is the transmission system used for digital radio. Not to be confused with Internet Radio Deezer One of the mainstream cloud-based music streaming subscription services available to users of audio products such as Sonos and Bluesound.
• DHCP (Dynamic Host Configuration Protocol): The automatic assigning of IP addresses to client machines logging into an IP network. This typically establishes a Local Area Network so that such devices may comminicate and interoperate. The same IP address, although technically temporary, may remain with a machine indefinitely unless a conflict arises with other devices on the network. The DHCP software, which resides in the router or a server, eliminates the need to manually assign permanent “static” IP addresses to devices. In a home network, the DHCP is typically in the wireless router.
• DIGITAL MEDIA HUB: A device that directs multimedia content streamed from the Internet to a stereo or home theater system. Also called a “set-top box” and an abundance of other names, it connects to an HDMI input on the A/V receiver or TV (see digital media hub names). Music-only hubs connect via audio jacks.
• DOLBY 5.1: An arrangement of six speakers, one of which is a low-frequency subwoofer speaker, used to create surround sound.
• DOLBY ATMOS: Complete three-dimensional surround sound. Effects are fired from all sides including above. Sound mixing is more true-to-life, providing advanced realism.
• DRM (Digital Rights Management): A system for authorising the viewing or playback of copyrighted material on a user’s computer or digital music player. DRM has centered around copyrighted music. As broadband Internet and more highly compressed video formats take hold, the focus of DRM broadens to video content.
• FLAC: FLAC is a free and open source audio compression format. It stands for Free Lossless Audio Codec. FLAC files use lossless compression, meaning that the file size is compressed while retaining full sound quality. FLAC encoded files can typically be compressed by up to 50%.
• HD (High Definition): In the context of video, this would be 1080p definition. In the context of audio this would be High-Res (High resolution music). High Definition refers to higher quality services. 4K is frequently referred to as Ultra HD.
• HDBaseT: HDBaseT, is a consumer electronic (CE) and commercial connectivity standard for transmission of uncompressed high-definition video(HD), audio, power, home networking, Ethernet, USB, and some control signals, over a common category cable (Cat5e or above) using the same modular connectors used by Ethernet. It is used for distribution and control of signals around the home and permits equipment to be located discretely out of the way to improve the aesthetic appeal of a room as well as its operational convenience.
• HDMI: A high-definition video and audio input used for connecting HD equipment, such as a Blu-ray player or a Sky HD box. Small screen TVs tend to have only a few, but most larger sets have three or four. An HDMI switching box can be used to add more ports High-Res Audio High-resolution audio, also known as High-definition audio or HD audio, is a term used by some recorded-music retailers and high-fidelity sound reproduction equipment vendors. It refers to higher than 44.1 kHz sample rate (typically 192 kHz) and/orhigher than 16-bit linear bit depth (typically 24-bit).
• HOME AUTOMATION: Home automation is the use of one or more computers or processors to control basic home functions and features automatically and sometimes remotely. An automated home is sometimes called a smart home.
• INTERNET OF THINGS (IoT): The interconnection of physical objects through electronics, software and wireless networks, enabling them to send and receive data. An example of a sustainable use of the IoT is a smart home hub which allows users to efficiently manage temperature, lighting and any other connected devices in the home.
• INTERNET RADIO: Digital radio that picks up its broadcasts from the Internet using your Internet connection. Not to be confused with DAB radio – they’re different technologies.
• SAMPLE RATE: Sampling rate or sampling frequency defines the number of samples per second (or per other unit) taken from a continuous signal to make a discrete or digital signal. The more samples taken per second, the more accurate the digital representation of the sound can be. For example, the current sample rate for CD-quality audio is 44,100 samples per second. This sample rate can accurately reproduce the audio frequencies up to 20,500 hertz, covering the full range of human hearing.
• SET TOP BOX: A device that converts video content to analog or digital TV signals. For years, the set-top box (STB) was the cable box that “sat on top” of the TV. Although no more flat surface to rest anything, the term lives on. A satellite TV set-top box is officially a “satellite receiver” and the box that converts over-the-air digital broadcasts to analog for old TVs is a “converter” (see TV converter box). Apple TV, Fire TV, Android TV and Roku boxes connect to the home network for Internet access and convert video from Netflix, Hulu and other providers into TV signals. These “media hubs” go by many names and may accept local content from the home network as well (see digital media hub).
• IP ADDRESS (INTERNET PROTOCOL ADDRESS): The address of a connected device in an IP network (TCP/IP network). Every desktop and laptop computer, server, scanner, printer, modem, router, smartphone, tablet and smart TV is assigned an IP address, and every IP packet traversing an IP network contains a source IP address and a destination IP address.
• LAN: A local area network (LAN) is a group of computers and associated devices that share a common communications line or wireless link to a server. Typically, a LAN encompasses computers and peripherals connected to a server within a distinct geographic area such as an office, home or a commercial establishment. Typically, in a home environment it is a router that establishes a LAN using both wired and wireless connections and a “DHCP” server.
• LATENCY: Latency refers to a short period of delay (usually measured in milliseconds) between when an audio signal enters and when it emerges from a system. Low-latency audio in is important for synchronising multi-room sound systems and lip-synching audio and video.
• LINEAR BIT DEPTH: In digital audio, bit depth describes the potential accuracy of a particular piece of hardware or software that processes audio data. In general, the more bits that are available, the more accurate the resulting output from the data being processed. Bit depth is frequently encountered in specifications for analog-to-digital converters (ADCs) and digital-to-analog converters ( DACs), when reading about software plug-in , and when recording audio using a professional medium such as a digital audio workstation or a Digital Audio Tape machine. Bit depth is the number of bits you have in which to describe something. Each additional bit in a binary number doubles the number of possibilities. By the time you have a 16-bit sequence, there are 65,536 possible levels. Add one more bit, and you double the possible accuracy (to 131,072 levels). When you have a 24-bit process or piece of 24-bit hardware, there are 16,777,216 available levels of audio.
• LOUDSPEAKER: A loudspeaker or speaker is a device that changes electrical signals into sounds loud enough to be heard at a distance.
• LOUDSPEAKER – ACTIVE: Active speakers also known as self-poweredspeakers and powered speakers, are loudspeakers that have built-in amplifiers. Sonos “Play” speakers and Bluesound “Pulse” speakers are examples of active speakers.
• LOUDSPEAKER – PASSIVE: A passive speaker does not have a built-in amplifier; it needs to be connected to your amplifier through speaker wire. This speaker-level signal has been amplified enough to drive the speakers sufficiently without the need for any additional electrical current.
• MATRIX SWITCH: A matrix switch is an electronic switch designed to route video and/or audio signals from multiple input sources such as cameras, satellite TV boxes, DVD/Bluray players, to one or more display/audio-ouput devices, such as monitors, projectors, and TVs. When combined with HDBaseT, this permits electronic components to be located and controlled when distant from the output devices. This helps improve aesthetics by the ability to conceal equipment and cabling.
• MESH NETWORKING: Mesh networking is a type of network topology in which a device (node) transmits its own data as well as serves as a relay for other nodes.
• MIDRANGE: A mid-range speaker is a loudspeaker driver that reproduces sound in the frequency range from 250 to 2000 Hz. It is also known as a squawker.
• MP3: MP3 (MPEG-1 Audio Layer-3) is a standard technology and format for compressing a sound sequence into a very small file (about one-twelfth the size of the original file). This makes the file fromat very portable but at high compression rates, it suffers from a reduction in audio quality. Other formats, such as FLAC and MQA are known as “lossless” codecs.
• MQA (Master Quality Authenticated): Is a High-Res Audio codec that captures 100% of the original studio performance. It then cleverly adapts to deliver the highest quality playback your product can support. MQA folds the file to make it small enough to stream over the internet. MQA is authenticated by the studio as true to the original recording. MQA is supported in all Bluesound and NAD/BluOS products.
• MUSIC SERVICES: Music Services such as Spotify, Deezer, Tidal and Napster are cloud-based, subscription-based, music-streaming services allowing a subscriber to choose from a wide variety of music which is streamed directly to their audio device(s) «on-demand».
• NETFLIX: Netflix is a US-based company that provides Internet-based video-on-demand services and content for a monthly fee.
• OK GOOGLE: “OK Google” is the voice command used to activate Google voice search on your Android smartphone and other Google devices. This can be accessed by opening your phone’s
• GOOGLE: Search app or Google Search widget and either tapping the microphone icon or saying “OK Google
• RIPPING: Converting an audio CD from its native format to MP3, AAC, FLAC or some other compressed audio format. The term was coined with a counterculture inference, because many tech-savvy people loved the idea they were “ripping off” the music industry by making copyrighted works available in a compact format that could be quickly downloaded over the Internet. Ripping is also called “importing.”
• RJ45: Short for Registered Jack-45, a RJ-45 is an 8-pin connection used for Ethernet network adapters to allow such devices to be physically connected.
• ROUTER: A network device that forwards data packets from one network to another. Based on the address of the destination network in the incoming packet and an internal routing table, the router determines which port (line) to send out the packet (ports typically connect to Ethernet cables). Routers require packets formatted in a routable protocol, the global standard being TCP/IP, or simply “IP.” In the home or small office, a “wireless router” is commonly used to manage Internet traffic. It is a combination device that houses a router, network switch and Wi-Fi in one box.
• SIRI: Apple’s virtual assistant, introduced with iOS 5 in the iPhone 4S in 2011. Siri pioneered the “intelligent personal assistant” in a mobile device by responding with both voice and visual results and ushering in a new era of convenience for users. Siri later moved from mobile-only devices to the desktop. In 2016, Siri was added to macOS 10.12 (Sierra), and it became the major feature in the table top HomePod in 2017.
• SMART HOME: A highly automated home. Also called the “connected home,” the dwelling is networked not only for computers and entertainment but also for security, heating, cooling, lighting, as well as control of appliances. A smart home might have Ethernet outlets wired into every room or may rely partially or entirely on Wi-Fi and other wireless communications such as Bluetooth, ZigBee and Z-Wave.
• SMART SPEAKER: A wireless speaker that includes other functions. For example, Sonos Play devices and Bluesound “Pulse” speakers.
• SONOS: A very popular multi-room audio system that unifies all the user’s local and Internet-based music sources and delivers them to wireless speakers throughout the home over Wi-Fi. Control is via the SONOS app in a PC, Mac, iOS or Android device, and SONOS CONNECT components can integrate an existing stereo, home theater or ordinary speakers into the SONOS wireless system.
• SONOSNET: Sonosnet is the operating system that enables the Sonos multi-room audio system (see Sonos).
• SOUNDBAR: Soundbars are long, often tube-link speaker systems designed to boost the sound of a TV by creating a stereo effect using a single cabinet. They have become more popular in recent years due to typically poor sound in modern, flat panel TVs.
• SPOTIFY: One of the mainstream cloud-based music streaming subscription services available to users of audio products such as Sonos and Bluesound.
• STREAMING: Transmitting digital audio or video content while users listen or watch. Material can be streamed from a private network or the public Internet. To the user, streaming is the same as listening to radio or watching cable, satellite or broadcast TV, except that a connection to the Internet is required. Like cable and satellite TV, content can be streamed on-demand or on a regular schedule. Unlike downloading files, which remain in the computer until the user deletes them, streaming content is automatically deleted from the computer, set-top box, smart TV or mobile device after being played. Because streamed content is actually being downloaded (if only temporarily), and downloading means transmitting to the user’s device, the term streaming is often erroneously used as a synonym for downloading, as well as any kind of transmission.
• SUBWOOFER: A speaker that reproduces the lower end of the audio spectrum. A subwoofer system typically includes a crossover circuit that filters frequencies around 100Hz and under to the driver. In a home cinema, the placement of front, center and surround speakers is critical to the listener, but subwoofers are non-directional and can be located in a convenient spot, although corners are not recommended. Passive subwoofers contain only the speaker (the driver) and crossover. Active subwoofers are self-powered and include their own amplifier.
• SURROUND SOUND: An arrangement of speakers designed to create a more immersive sound wrapping itself around the viewers. For 5.1 surround sound, you’ll need five speakers and a low-frequency subwoofer – hence the ‘five plus one’. For 6.1 and 7.1 surround sound, you’ll need to add one or two more speakers respectively. You hook a surround sound system up to your TV using a digital coaxial or digital optical connection.
• THX: A design system that provides realistic sound playback for movie and home theater from THX, Ltd., San Rafael, CA (www.thx.com), an independent spin-off from Lucasfilm, Ltd. The THX Sound System was developed during the production of the Return of the Jedi in 1982 and named after George Lucas’ first film, “THX 1138.” THX includes a custom design for each movie theater auditorium as well as special speakers and electronics.
• TIDAL: One of the mainstream cloud-based music streaming subscription services available to users of audio products such as Sonos and Bluesound. Tidal majors on sound quality and it has adoped MQA (see MQA) to deliver High-resolution music to its subscribers. To listen to MQA encoded music, subscribers must also use MQA enabled hardware for playback.
• WAN: Wide Area Network. A long-distance communications network that covers a wide geographic area, such as a state or country. The telephone companies and cellular carriers deploy WANs to service large regional areas or the entire nation. Large enterprises have their own private WANs to link remote offices, or they use the Internet for connectivity. The Internet is the world’s largest WAN.
• WIRELESS ROUTER: A hardware device that provides the basic infrastructure for a home or small office network. By combining three network components in one box, wireless routers offer a convenient way to connect a small number of wired and any number of wireless devices to each other for access to the Internet as well as for file sharing and printing. Also see “router”.
• WIRELESS SPEAKERS: Wireless speakers are loudspeakers which receive audio signals using radio frequency (RF) waves rather than over audio cables. Typically they may be controlled via an app, music streamed from the cloud or via bluetooth. Examples are Sonos and Bluesound.
• WOOFER: A low-frequency loudspeaker. A hi-fi speaker cabinet typically contains a low-frequency bass speaker (woofer), a mid-frequency midrange speaker and a high-frequency treble speaker (the tweeter). In a two-way system, only woofers and tweeters are used. However, there are countless high-fidelity loudspeaker configurations on the market, many with more than one speaker of the same type within the enclosure.
• ZIGBEE: A wireless mesh network used for home, building and industrial control. It conforms to the IEEE 802.15.4 wireless standard for low data rate networks. With a maximum speed of 250 Kbps at 2.4 GHz, ZigBee is slower than Wi-Fi and Bluetooth, but is designed for low power so that batteries can last for months and years. The typical ZigBee transmission range is roughly 50 meters, but that can vary greatly depending on temperature, humidity and air quality. Mesh network enables devices to repeat signals to and from each other. Typically used in home automation projects to enable control of lights, blinds, relays, audio equipment.
• Z-WAVE: A wireless network for controlling lights, heating and air conditioning, appliances, home security and home theatres. Z-Wave is designed for low-speed controls such as turning a device on and off or raising or lowering a function, and it operates in a mesh topology. Each Z-Wave device can relay signals from another device for better reception. Working in the unlicensed 902-928 MHz band, Z-Wave devices do not interfere with Wi-Fi and other products that use the 2.4 GHz band.

While there are definitely much more terms that could be included in a Hi-Fi glossary, we hope you found this short glossary helpful. Let us know if you have any questions or if there are any other terms you would like to know more about.