Baffled by terminology? Check out our handy guide.

0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


 Glossary 0-9

The extra visual dimension. Creates depth of field in an image either passively or actively. You need glasses regardless. Over to you.

Generic term for UHD or Ultra High Definition. Basically it’s twice the resolution of 2K (1080p)


 Glossary – A

Loudspeaker design which typically has a crossover and an amplifier built-in. They can be connected directly to a pre-amplifier, and both require a mains power connection. More complex designs employ a powered crossover which splits the audio signal at frequency level before being sent to the amplifier. This allows for greater resolution and lower distortion when compared to passive loudspeaker designs.

Not a hard-sell or a smack on the nose, but a Hi-Fi system with a tendency to over-expose the higher frequencies.

Another Apple protocol for wirelessly streaming data between Apple products. Now licensed out to other clients.

A sense of space, or venue, within an audio recording.

The engine of any Hi-Fi or Home Theatre system. It receives the low-level signal output from sources such as CD Players, Turntables, Tuners, Blu-Ray Players etc, and increases the signal high enough to drive your loudspeakers. Various designs apply, and usually include a volume control.

The domain in which we all hear and see.

Something to do with your state of mind, and the resultant medical care required to remedy it.

Because most film negatives are a different shape than the widescreen format ratio (16:9), this process modifies the negative to allow the whole of the frame to be viewed.

Short for Application. Computer software programs that can be used on smartphones, tablets, laptops and desktop devices. Most home cinema and Hi-Fi manufacturers now also offer Control Apps to drive their equipment.

Apple Lossless
A fruit farmer that has been well & truly scrumped. Not really. This is Apple’s clever little compression format for getting music onto their devices, in slightly better quality than the MP3 format. However, it’s not lossless.

Aspect Ratio
The correlation between the width and the height of the screen or negative. Common values are 4:3 and 16:9.

Nothing to do with Pvt. Jones (Dad’s Army) shouting “They don’t like it ‘up ’em Mr. Mainwaring!”, but rather the ability of a Hi-Fi system to reproduce the initial percussive transient of a musical tone.

A person who is enthusiastic about high-fidelity sound reproduction. Don’t worry, you don’t have to be on a special list somewhere to qualify as one. However these people are difficult to spot, as they appear to behave perfectly normally, and look exactly like you and I.


 Glossary – B

Nothing to do with your general demeanour, but a professional 3-pin, earthed, click-fit connector. If your system has one, use it.

A speaker cabinet design that utilises a port, which acts to extend the bass response.

Where each driver unit of a loudspeaker is driven by a separate amplifier.

This can give some of the benefits of Bi-Amping, but at lower cost. The design of many loudspeakers will allow separate runs of speaker cable to each drive unit.

Simply refers to the number of bits used per-sample. CD audio has a depth of 16 bits, which can rise to a theoretical 24 bits in the case of higher resolution audio files.

A digital audio file is measured in kilobits-per-second (kbps). Theoretically, the higher the bitrate, the better the sound quality.

Not a pornographic sci-fi movie, but rather a High Definition video format that comes dangerously close to emulating the original film print, and with studio-quality audio to boot.

Neither the name of a pirate, nor an odd dental problem, but rather a protocol for transmitting data wirelessly between devices. AptX is an upgrade to the existing Bluetooth standard, offering higher quality audio transmission. Kleer is a similar alternative.

Beyonce, Brad Pitt, Gigi Hadid, George Clooney, Kendall Jenner, Tom Hardy, Idris Elba…oh sorry. This means a fullness of sound, the opposite of thin & reedy.

Boom / Boomy
Exaggerated low or bass frequencies. Can be caused by poor loudspeaker placement, or the natural acoustic of a particular space.

Much the same as aggressive. The Hi-Fi system is exaggerating the high frequencies, meaning the sound becomes edgy and irritating. The long-term effect can dislodge a filling or two.


 Glossary – C

Custom In-Ear Monitors. A design of earphone that moulds exactly to the shape of your ear.

The stylus and armature arrangement for playing vinyl records. Various designs apply, including moving magnet, moving coil, and moving iron. Very retro, but utterly brilliant and moving back into vogue.

Presentation is overlay accurate, at the expense of musicality. Taken to excess can produce a very sterile sound.

White or grey, fluffy, sometimes wet. Up in the sky. AKA: The Internet.

A 75ohm balanced cable construction which can be used to send electrical or digital information.

Any change in the character of the sound which makes a note, voice, or instrument sound unnatural.

Don’t worry about the technicalities, just take it from us – you don’t want it. It’s horrible. (Unless you’re a sound engineer, in which case you understand how, why and when to squash the frequency range.)

A circuit board found inside a loudspeaker which splits the incoming audio signal, by frequency, to the various individual drive units. High frequencies get routed to the “Tweeter”, whilst low frequencies get routed to the “Woofer”.


 Glossary – D

Digital Audio Broadcast. Digital radio, to you & me.

The next generation of DAB (Digital Radio). The specifications include a significant upgrade in audio quality. Most existing DAB receivers are not forward compatible, annoyingly.

Digital-to-Analogue Converter. This little gizmo turns all of those 0’s and 1’s into something our ears recognise. Simple eh? Not really. Maybe later.

These are a bit like MP3 players – not! Many are capable of storing and playing high resolution audio files (24bit) with very high sampling rates. Prices range from a few hundred pounds to many thousands. Build quality and design can be space-age with some brands. We luv ‘em so talk to us.

Opposite of bright. Or perhaps the fuse has blown?

dB. A measurement of sound pressure.

Or low-level detail, definition, transparancy, or transparent. All mean the same thing. You can never have too much detail.

The opposite of analogue.

Digital Audio Files
FLAC, WAV, WMA, ALAC, MP3, ATRAC. These are all different versions of the same thing – compressed digital storage files. Their individual qualities and abilities are hotly debated by audiophiles.

Digital Light Processing. One of several different kinds of projector technology.

Dolby TrueHD, Dolby Digital, Dolby Surround, Dolby Pro-Logic are all variations of principally the same thing, namely noise reduction processing. These are used as compression systems (mainly in the film industry) to get the original multi-channel soundtrack onto the film format with very little loss of quality. Dolby TrueHD is termed as Lossless.

Dolby Atmos
The latest surround sound format. It is an object-based surround technology that creates a 360° sound field. It’s brilliant and requires many speakers to perform properly. Talk to us.

Dolby Vision
This is Dolby’s clever little codec designed to push HDR to its theoretical limits.

Direct Stream Digital. Originally an alternative codec to MLP invented by Sony for the SACD format. More and more DAC’s are adding DSD compatibility to their roster of features.

Digital Theatre Systems. This is an alternative to Dolby. The differences are hotly debated.

DTS-HD Master Audio
Equivalent to Dolby TrueHD, i.e. Lossless film audio. Many argue it’s better than Dolby.

This is DTS’s version of Dolby Atmos. The usual Dolby vs DTS arguments apply.

Digital Versatile Disc. Been around since 1998. Now usurped in every way by the Blu-Ray format.

High resolution audio format also capable of surround as well as stereo, which had at one time been thought to replace CD.

Digital Extreme Definition. Digital editing site for DSD.

The ability of a system to reproduce contrasts between quiet and loud, with energy and dynamism.

Dynamic Range
The difference between the quietest and the loudest parts of a recording and measured in decibels. The greater the range the more realistic the sound will be.


 Glossary – E

A specific type of loudspeaker (or headphone) design which utilises a membrane or filament suspended in a statically charged field. While this design can be limited in frequency range, its one great virtue is extremely low distortion.

Standardised hard-wire connection for computer networks, now widely used for audio & video streaming services.

A very “en-vogue” word. We think it is describing the inherent distortions and colourations found in most valve designs. We don’t have a problem with ear-friendly distortions and colourations, we just think this word is gobbledegook.


 Glossary – F

One who removes fluff and dust from a stylus, both before and after the playing of a vinyl record.

A 1970’s progressive jazz/rock band from Holland, a small family car, and a now-defunct chain of DIY stores.

See “Aggressive”.

Free-to-air digital TV from the same Astra 2 satellite as Sky TV. HD available.

Free-to-air digital TV using existing aerial connections. HD available.

Frequency Range
See “Frequency Response”.

Frequency Response
Term used to describe the ability of a Hi-Fi system to reproduce the entire frequency band, from the lowest to the highest.


 Glossary – G

Speak to a French Polisher. Normally refers to an “edginess” in high frequencies.

Speak to a Wrestler.

See “Grip”.


 Glossary – H

HD 1080p
Also called Full HD. Denotes a devices capability to display the current high-definition standard without down-conversion (measured at 1920×1080 pixels).

HD Audio
See DTS-HD Master Audio, Dolby TrueHD, L-PCM and DSD.

High Definition Compact Disc. A codec invented by Pacific Microsonics to cram more data onto a standard CD. Very effective, but you need a decoder to unlock the data. HDCD’s do sound better than standard CD’s.

High-Definition or High-Bandwidth Digital Content Protection. An anti-copying mechanism found in all HDMI-enabled equipment.

High Definition Multimedia Interface. High-quality ultra-fast cable connection used for transmitting high-definition audio and video signals. HDMI version 1.4 (or High-Speed with Ethernet) compliant devices will now also be capable of 3D Video and Networking. Current version is at HDMI 2.2 for 4K.

High Dynamic Range. Basic principles go back 150 years to the early photographic pioneers. The modern version can be traced back to the 1950’s for military use, then to medical photography via satellite imaging. The Digital version of HDR was invented in the early 1990’s. There’s lots of science and maths involved, and words like Gamma and Luminescence crop up a lot. Basically HDR means brighter whites, deeper blacks, greater contrast, and a much richer colour palette.

Similar to an Audiophile, but for people who more (or less) exclusively listen to their music on headphones. These people move freely amongst us, and are generally very easy to spot.

The space above one’s head, and also the surname of a 1980’s faux computer-generated character. Also the additional power output capability of an amplifier when producing short-term peak signals. Also the name of an excellent Hi-Fi show organised by Unilet Sound & Vision.

High or Higher Fidelity.


 Glossary – I

Put this little letter in front of any product name, and some people will automatically go out and witlessly purchase it.

In-Ear Monitor. Headphones which fit inside the ear, also called Earphones.

The ability of the Hi-Fi system to accurately place a sound source in the stereo field. Is there a precise left, right and centre? No? You’re got a problem. Talk to us.

The measure of resistance to the alternating current (AC) in an electrical circuit. Measured in Ohms (Ω). All loudspeakers offer resistance to the amplifier, therefore limiting it’s potential capability. The lower the impedance value of a speaker, the more current is required from an amplifier, and the harder it is to drive.

Infinite Baffle
Loudspeaker design utilising a completely sealed cabinet.

Opposite of “Progressive”, where all the individual elements of a picture are sequenced together (i.e. 1080i, 576i).

Internet Radio
Literally thousands of radio stations whose output is available via the internet, either for free, or via a subscription. Many Hi-Fi and Home Cinema manufacturers now include network connectivity on their products for the purpose of receiving these stations.


 Glossary – J

You’re looking at it.

Audible digital noise or an involuntary psychosomatic reaction felt just prior to receiving a bill.


 Glossary – K

1000 bits. The unit used to express the size of a digital audio or video file. The speed at which such files can be delivered (i.e. Played) by a system is measured in kilobits-per-second (kbps).


 Glossary – L

Liquid Crystal Display. An alternative to Plasma displays, but traditionally found in smaller screen sizes. Not any more!

Light Emitting Diode. Now used as a back-light for LCD screens as an alternative to fluorescent. Not to be confused with OLED technology.

Low Frequency Effect. This is the .1 or Subwoofer channel within movie soundtracks.

One who exclusively uses a disc-based system, i.e. CD, Blu-Ray etc.

A clever invention of computer companies and their marketing departments, and a total contradiction in terms. There is only one lossless format, and that’s the original recording.


 Glossary – M

Process in the which the original source recording is converted into a Master Copy, from which subsequent copies can be made. The quality of the final result can be dependant on the competancy of the Mastering Engineer, and the choice of equipment used to create the Master.

Industry standard mobile audio/video interface that allows the connection of smartphones, tablets, and other portable consumer electronics devices to high-definition televisions (HDTVs), audio receivers, and projectors.

Music Library Management. A sophisticated software package that allows you to manage your stored music library. Many types are available but for audiophile purposes the package called Roon is currently king of the hill. Call us and we will tell you why.

Meridian Lossless Packaging. Originally an alternative codec to DSD, developed by Meridian Audio for the DVD-Audio format.

A single mono amplifier. You’ll need two for a stereo system, and five for a surround-sound system.

Master Quality Authenticated. An audio compression codec invented by Meridian Audio claiming to preserve the quality of the original master audio file.

The word we all love to hate. Does the music sound right to you? Yes? Then the Hi-Fi system you’re listening to has musicality, and needs buying.


 Glossary – N

NAS / NAS Drive
Network Attached Storage. An independent, stand-alone data storage solution which can be readily accessed by audio/video streaming devices.

Network Player
Any device that plays media over a network. Simples.

No Fault Found. See the Unilet Service/Repair Department.


 Glossary – O

Organic Light Emitting Diode. The next generation of TV screens that supercede LCD and Plasma displays. The one domestic vision product available, to date, which is closest to the human eye.

Relates generally to the mid and high frequencies of an audio recording. Presented properly, they can give a sense of airiness and space within any given sound stage.

You may need some new glasses, but that has nothing to do with this. Fibre Optic cable for transferring digital data via light. Very fast, and theoretically unlimited in capacity.

On-The-Go. Dedicated digital audio only for Android devices.

Standard sampling rates are 44.1KHz (for CD), 48KHz (for DVD), and 96KHz (for Blu-Ray and uncompressed LPCM). Oversampling is the process of multiplying these native sample rates in an effort to improve resolution and reduce noise. We remain unconvinced about the latter, but people do seem to like the larger numbers.


 Glossary – P

Pulse Code Modulation. A digital encoding and storage system. Uncompressed PCM (LPCM – 24bit/48 or 96khz) is the recording industry standard for both music and movie audio.

One who exclusively uses portable devices as a sound source. Usually with headphones.

Power Handling
The highest safe power for loudspeakers. Measured in watts. Great fun to exceed.

A device which allows ethernet connectivity over an electrical ring main.

Partner Purchase Approval. The act of seeking permission from your significant other. Usually before committing to the purchase of a really great hi-fi system or new piece of equipment. AKA Wife/Husband Acceptance Factor.

Pace, Rhythm, Attack, Timing. Apparently all absolute requirements of any Hi-Fi system, according to some reviewers and critics. Poor choice of acronym, though.

Progressive Scan
A system which gives clearer, flicker-free images from DVD or Blu-Ray in comparison with the conventional horizontal line refresh system (Interlaced).

Punch / Punchy
Speak to someone from the International Boxing Federation. Also an adjective to describe a type of low frequency presentation.

Personal Video Recorder. Modern equivalent of a VCR, usually an add-on box for Digital TV which uses a big hard drive to record, store and playback TV broadcasts.


 Glossary – Q

Precursor to surround sound systems, which required four separate, equal channels of audio.


 Glossary – R

RCA / Phone / Single-Ended
All various names for the standard 2-Pin line level connector.

Is your hairline receding? Is it a cunning invention of politicians and economists? Whatever, neither should deter you from buying awesome Hi-Fi and Home Cinema. Life’s too short.

Colloquial term for software and/or hardware that allows you to copy digital music files.

Room Correction
Speak to an Interior Designer. Also fast becoming the Holy Grail for enthusiasts of surround sound and Home Cinema systems. The act of acoustically treating a space to correct for sonic imperfections and unwanted reflections.

A word used to describe unwanted low frequencies.


 Glossary – S

Super Audio Compact Disc. A competitor to DVD Audio which offers superior performance to CD.

Sample Rate
The number of times the amplitude of an audio waveform is measured (i.e. Sampled) per-second. The higher the number, the more accurate the digital reproduction of the analogue recording. For instance, CD audio is sampled 44100 times every second, and DVD is sampled 48000 times every second. Wow!

SD Card
Secure Digital Card. Not a type of ID or bank card, but rather the name of a completely solid-state memory card. Now widely used for audio/video storage because of its ability to store very high bitrates with extremely low jitter.

A word used to describe ultra-low bass frequencies. Alternatively speak to a Geologist.

“Here’s your food order – Enjoy!” No, actually a computer-based device or application which manages access of resources and services across a network.

Horrible in audio, and a totally over-used setting on Televisions.

Where the “S”, “F” and “T” sounds are over-emphasised, assuming it doesn’t occur naturally. Freddie Mercury, for instance, did have a natural lisp.

Check your pocket. The ubiquitous mobile communications/computing device of the masses, although Star Trek got there first.

Smart TV
Any TV which has internet connectivity, which nowadays the vast majority do, in some form or another.

Sound Bar
Not a nightclub, but rather an under-TV single-box device containing multiple speakers and surround sound processing. Useful if you don’t fancy a full surround system, and getting better all the time. However, no substitute for a discrete multi-channel surround system.

Does the music sound fast enough, or is it dragging? Just as in music, correct timing is very important in a sound system. Too much bass and the music may sound slow.

Sound Pressure Level. This is the local sound deviation from ambient pressure caused by a sound wave. In other words, how loud the music is.

“It takes two, baby.”

A place to put your media. Can refer to old-school record racks or CD shelves, or nowadays memory space for digital files.

Device which allows the streaming of digital audio/digital files.

One who acquires, or listens to music primarily via the internet or a digital storage medium.

On-demand delivery of digital audio/video files from any form of media storage. This includes from the internet, from Cloud storage, or any form of local storage.

Loudspeaker dedicated to bass, or low frequencies. Commonly found as part of a 5.1 surround sound systems.

See also Asynchronous, Isochronous, and Adaptive, all of which refer to the transfer of data via USB. The devil is very much in the detail here, and the final quality can be extremely variable. Talk to us!


 Glossary – T

See “Body”.

Acronym which allegedly stood for “Tomlinson Holman Experiment”. A performance benchmark generally passed by many Home Cinema products as an assurance of quality. THX is a brand, not a sound format, contrary to popular belief.

The tonal character of an instrument or voice.

See “Speed”. It’s also something that most Unilet sales staff are rather bad at, before 9.30am.

See “Attack”.

Transmission Line
A type of loudspeaker design which uses an internal labyrinth construction to extend the bass response.

One who is an avid listener of radio broadcasts, digital or otherwise.

A record player to you & me. Many people under the age of 30 still struggle with this term, however just like records, the world is turning, and vinyl is coming back in a big way.

The act of tuning a Hi-Fi system by whatever means available, thereby hopefully getting closer to the best possible performance.

A practitioner of the “Tweak”. Not to be confused with Twerk.


 Glossary – U

UHD Blu-Ray
Blu-Ray Disc carrying video content at 4K resolution. A standard Blu-Ray machine will not play this type of disc, so check before you buy.

Established 1969. Still here. Need we say more?

Universal Serial Bus. The computer industry standard connection for peripherals, now becoming heavily adopted into the audio/visual industry for data transfer.


 Glossary – V

Similar to an Audiophile, but for people who are enthusiastic about picture quality on their TV’s, camera’s, or projection devices. These people are quite easy to spot due to the dark circles under their eyes.

The king of all music formats. Nothing sounds quite as good.


 Glossary – W

Similar to “Body”. Cuddly, cosy etc.

Want more power? Then you need more watts! Loudness is something else, however, which depends more on loudspeaker sensitivity.

See “Vernon”.

Now-commonplace technology that facilitates wireless connectivity between digital devices. Now entering it’s 5th generation of development (5G).


 Glossary – X

That certain something which defines an awesome Hi-Fi system. Or a popular TV programme format (which replaced Opportunity Knocks, if you’re of a certain age).


 Glossary – Y

Physically exhausting method of getting your brand-new system home because your significant other is using the car.


 Glossary – Z

See “Abbey Road”. Even though it’s the wrong crossing.