If you don't know your woofers from your tweeters, or you're baffled by technology, let us help you out! This handy jargon buster has been designed to demystify some of the most common hi-fi and home cinema terms. We've tried to explain some of the more exotic functions and facilities you might encounter on this site in layman's terms. We hope you'll find it useful.
This is the highest of the high, so to speak, being the best quality
High Definition standard. Also known as ‘True HD’ or
‘Full HD’. Blu-ray and HD DVD discs offer such pretty
pictures, although not all screens can accept them. The number
‘1080’ represents the 1,080 lines of vertical resolution,
progressively scanned (see entry). The term usually assumes a
widescreen aspect ratio of 16:9, implying a horizontal resolution of
1920 pixels. This creates a frame resolution of 1920×1080, or
2,073,600 pixels in total.
(Advanced Audio Coding)
A popular digital audio encoding system that compresses data files for
greater storage capacity – think of the music tracks stored on an
iPod and you’re on the right track. AAC is similar to MP3, but
offers superior quality and DRM support. AAC is the preferred coding
system of Apple, so, for example, you’ll find tracks on iTunes
encoded this way. A typical files size is 4MB.
Pretty much does what it says on the tin. In hi-fi terms this is an
electronic device that amplifies or boosts the signal from a source
component to a required volume. Also see Pre-amplifier and Power
For hi-fi buffs this refers to a way of recording and its related
playback. So analogue should bring to mind images of turntables and
tape recorders (and men with long beards) as opposed to portable MP3
devices, compact disc and DVDs. An analogue recording is one where the
original audio signal and its corresponding waveform are modulated onto
a physical media or substrate, such as the groove of a record. A
physical quality in the medium (e.g. the shape of a record groove) is
directly related or analogous – geddit – to the physical
properties of the original sound's waveform. See Digital.
A device – normally integrated into the screen or a set-top box
– that allows one to receive conventional TV stations, e.g. BBC1.
All systems preceding digital transmission, such as NTSC, are analogue
television systems. This older television broadcast signal is being
phased out in the coming years – meaning analogue tuners will be
useless. It will be replaced with a ‘digital’ signal.
The displayed width of an image divided by its height. A bit too much
like maths? Okay does your picture look square or more like a
letterbox? These are the two main aspect ratios around - the
traditional 4:3 and its modern 16:9 (1.78:1) successor, used in HD
television or the cinema. Conversion between formats can be
accomplished by either cropping the image to fit the receiving format's
ratio or adding black bars (the letterbox we spoke of earlier) to
retain the original format's ratio.
How low can you go! Sorry. This is the lowest part of the frequency
range, which is reproduced by woofers and subwoofers in loudspeakers.
The scary rumbling often heard in home cinema demonstrations is a
classic example of extreme bass.
A simple and cost effective way to improve the sound of your system or
simply a complex version of the Emperor’s New Clothes: the jury
is always out on this one. Bi-wiring is essentially a bewildering way
of connecting speakers to amps, which is said to improve sound quality.
The technique makes use of the two sets of speaker terminals commonly
found on the rear of loudspeakers, and keeps high notes separate from
mid/bass frequencies in the cable runs. This is meant to keep the
respective frequency signals cleaner as they don’t mix with each
Bit and bit rate
A bit is the smallest component of a digitized musical signal. Compact
disc, for example, is made up of 16 of these bits. A bit rate measures
the speed of this data when it is transferred. Also used as a measure
of quality for digital music, where the greater the Kbps or Mbps the
superior the sound. See Digital.
Blu-ray disc (BD)
Blu-ray is a high-density optical disc format for the storage of
digital information. Or in other words, something a bit like a DVD, but
a whole lot better. DVD, turbo-charged. When properly implemented it
offers superior image and sound quality over DVD. The format was
developed to enable recording, rewriting and playback of
high-definition video (HD), as well as storing large amounts of data.
The format offers more than five times the storage capacity of
traditional DVDs – up to 50GB on a dual-layer disc. Named after
the blue-violet laser used to read the new discs, it is backed by Sony,
Pioneer, Samsung and Apple amongst others.
This is the amount of light that is emitted from any screen or
projector and perceived by the eye. Brightness of screens is measured
in cd/m squared, while for projectors it is measured in ANSI (American
National Standards Institute) lumens. For both, the brighter the model
the higher the rating. Remember, as with power in an amplifier, the
biggest number doesn’t always equate to the best performance.
Equally, if a TV cannot deliver a bright image, you’ll need a
dark room, and this isn’t always possible.
The more colours a screen can produce, the more natural the image will
appear. Plasma screens create colours by combining red, green and blue
light. LCD screens create colours by removing colours from white
backlight. Plasma’s additive process tends to work better,
producing 90 per cent of the available colour spectrum, compared to
around 75 per cent for LCD screens.
The highest quality analogue video connection available. It is a method
of connecting any video source - think DVD player or games console
– to a screen or video projector. It cannot carry an audio
signal. The component connection splits a picture into three channels.
Consequently, component cables comprise three phono-type (or RCA)
sockets, which are coloured green, blue and red. Has now been overtaken
by HDMI connections in the quality (and convenience for that matter)
This is the difference between the lightest and darkest content that a
screen or projector is capable of producing. A high contrast ratio is a
desired aspect of any display, but with the various methods of
measurements, remarkably different measured values can sometimes
produce similar results. Remember that the contrast ratio promoted in
marketing literature is always measured under the optimum condition of
a room in total darkness. In typical viewing situations the contrast
ratio is significantly lower, making it harder to distinguish between
different devices with very high contrast ratios.
The part of a loudspeaker that splits the incoming audio signal into
separate frequency bands, and then sends these signals to specific
drivers, such as the tweeter or woofer. They have a huge influence over
the final sound of a loudspeaker design.
Digital Audio Broadcasting. A digital radio transmission that gives a
clearer signal, greater selection of radio stations, and wonderful ease
of access. What’s more, as well as sound, this technology allows
the broadcast of station information and EPG. Look out for DAB+
technology, which offers superior sound. Sadly there won’t be any
commercial broadcasts for at least five years!
Digital to Analogue Converter. Used in CD players and other digital
hi-fi or home cinema components to change digitized information back
into an analogue waveform that the amplifier and speakers can process.
Digital-to-Analogue Converter. A bit like a mini computer. DACs are at
the beginning of the signal chain, which makes them very important to
system performance. Video signals from a digital source, such as a DVD
player, must be converted to analogue form if they are to be displayed
on an analogue monitor. All new flat screens incorporate either a DVi
or HDMI connection, bypassing these devices and sending the signal
directly to the screen.
Any system that represents analogue signals as streams of numerically
encoded data. Think of all those green bits in the Matrix. Digital
systems use individual values (often electrical voltages) representing
numbers for input, processing, transmission, storage, or display,
rather than a continuous spectrum of values, as in an analogue system.
A digital tuner, such as those often integrated into screens, receive
signals via airwaves, satellite or cable, and translates them into a
signal the device can display. For example, with digital TV, a digital
tuner receives sound and pictures from the broadcaster in
‘bits’ of information and turns this signal back into
pictures and sound.
How big is yours? Dimensions of a component normally excluding any
stand, bracket or detachable speakers.
DivX is a brand name of products created by DivX Inc., which have
become popular due to their ability to compress lengthy video segments
into small sizes while maintaining relatively decent visual quality. It
is commonly associated with burning or ripping audio or video material
onto a hard disk. Many newer ‘DivX Certified’ DVD players
are able to play DivX encoded movies.
This is the technology that puts the cinema into 'home cinema'. When a
bullet whizzes across your front room, thank Dolby. Essentially it is a
digital audio format that delivers surround sound replay, via a 5.1
speaker system. It is the designated audio standard for DVD worldwide.
Dolby Digital is also the preferred multichannel audio standard for
direct broadcast and digital cable systems.
Dolby Digital EX takes the Dolby Digital 5.1-channel setup one step
further with an additional centre surround channel (reproduced through
one or two speakers) for extra dimensional detail and an enveloping
surround sound effect.
Dolby Pro Logic was the foundation for multichannel home cinema, being
the consumer version of the original Dolby multichannel analog film
sound format. In the good 'ol days, when a Dolby Surround soundtrack
was produced, four channels of audio information — Left, Centre,
Right, and Mono surround — were matrix-encoded onto two audio
tracks. These two tracks were then carried onto sources such as
videotapes — remember them? — from which decoding by Dolby
Pro Logic® recreated the original four-channel surround sound
experience. The quality is limited, most notably by the mono, reduced
bandwidth signal to the rear effects speakers.
Pro Logic II, Dolby Pro Logic IIx
and Dolby Pro Logic IIz
Like Pro Logic (above), Pro Logic II turns a properly encoded two
channel source into a full blown 5 channel signal. Improvements over
the original Pro Logic include better channel separation and a full
bandwidth, stereo signal to the rear speakers. The IIx version offers
6.1- or 7.1- channel playback. This is taken further still with IIz. It expands a 5.1 signal to 7.1 or even 9.1 with front height speakers.
Dolby® TrueHD is Dolby’s next-generation technology developed
for High Definition media. Dolby TrueHD delivers a sound that is
bit-for-bit identical to the studio master. The 100 percent lossless
coding technology offers up to 18Mbps bit rate and supports up to eight
full-range channels of 24-bit/96 kHz audio. It is also HDMI compliant.
Really rather good.
Another way to describe the round cones in a loudspeaker that create
sound. For those that care, these mechanical devices push air in a
pistonic manner to create sound waves.
Another multi-channel decoding format, similar to Dolby Digital, that
delivers surround sounds in the home. Often felt to have a slight
edge over Dolby in terms of performance, thanks to an enhanced dynamic
range and improved frequency response. DTS uses higher data rates
(1.5 Mbit/sec or 754 kbit/sec, which are almost twice to four times
higher) to encode the 5.1 channels of surround sound information than
Dolby Digital (448 kbit/sec or 384 kbit/sec). It's hard to tell
the difference, to be honest, and you'll always find both decoders on
A next generation surround sound technology that is capable of
delivering audio bit-for-bit identical to that of the studio master.
DTS-HD offers audio at super high variable bit rates - up to 24.5
mega-bits per second (Mbps) on Blu-ray discs and 18.0 Mbps on HD-DVD -
that are significantly higher than standard DVDs. It can offer
audio at 7.1 audio channels at 24-bit/96kHz that are identical to the
original. Another great piece of technology, similar to Dolby® TrueHD.
Players that can play both Blu-ray and HD DVD discs. So far
these haven't quite been the Holy Grail they sound like, due to some
limitations replaying one or both formats.
A ‘next generation’, extremely high quality audio system
Digital Versatile Disc-Audio uses a DVD’s superior storage
capacity to offer a sonic improvement over conventional CD replay. Not
only can it deliver stereo at 24-bit/192kHz quality, but also surround
sound recordings in 24-bit/96kHz. Sadly, it never really caught on and
there is extremely limited software availability.
The Digital Visual Interface (DVI) is a video interface standard
designed to maximize the visual quality of digital display devices like
flat screens or projectors. As a high quality, picture only connection
it sends the signal uncompressed from a DVD player to a screen. It is
available in A (Analogue), D (Digital) and I (Integrated – both A
and D) versions. DVI-D or DVI-I sockets can be part of the requirement
for High Definition TV.
These burn programmes onto recordable DVDs, offering a more durable and
compact alternative to VHS tapes.
The dynamics of a system refer to its reproduction the quietest and
loudest parts of a piece of music. A highly dynamic system can go from
extremely quiet to extremely loud as swiftly and easily as Lewis
EPG (Electronic Programme
These are found on Freeview units and simply list programmes on all the
TV channels – usually for seven days. It makes programming a
This is digital TV for those who don't want to see large chunks of cash
disappear from their bank account every month. It gives a great choice
of free digital channels, and is available built-in to some screens and
DVD recorders, or as a separate box.
Freeview HD gives up to 5 times the detail of ordinary Freeview TV and is the perfect match for your HD (High Definition) TV. Available in 720p or 1080i, Freeview HD matches the best currently available from broadcast technology.
Is it a high note or a low note? The former would live near the bottom
of the frequency range, while the latter lives up top. A bass guitar
produces mostly low frequencies while a flute or whistle produces high
frequencies. Frequency is actually the pitch of a signal and is
measured in Hertz (Hz).
A music recognition database based on the voluntary contribution of
information from users. Most music software connects to CDDB to
retrieve track names and band data for any given CD and some hardware
– such as music servers – have the database built-in.
An internal disc, such as those found in a computer, that stores large
amounts of data. Typically such designs are capable of storing many
gigabytes (GB) of data. Now a regular feature of MP3 players, DVD
recorders and DVRs.
(hard drive/disk) recorders
Components that offer an internal disk, like a computer, that can store
large amounts of video and audio information. Not only found on DVD
recorders, but also some Freeview and satellite boxes. They have a huge
storage capacity (e.g. up to 4TB for hundreds of hours of programming).
They also offer excellent editing tools so you can cut out ad breaks
At its most basic level, HD means better pictures. It is both a
broadcast and a screen technology, and there are three types: 720p,
1080i and 1080p. Any screen implementing these standards is called
‘HD ready’. However, to aficionados, 1080p, which is
sometimes called Full HD, is considered the only ‘true’ HD
The second format (with the other being Blu-ray Disc) that sought to
take over from DVD. Lost out in the battle against Blu-ray and was only ever used by a handful of companies, mainly Toshiba.
HDCP (High-bandwidth Digital
This system prevents unauthorised copying of data by ensuring that a
digital data stream is not intercepted between source and display.
Featuring in HD Ready screens, it means that you cannot make recordings
of your high-definition programming, even if you have a high-definition
recording device. The HDMI sockets on any HD Ready-badged TV must be
HDMI (High Definition
A wonderful 'pure' digital, high quality connection between a source
and screen. It can carry both sound and vision between home cinema
components. In its 1.3 guise it is able to carry high-def audio and
greater colour spectrum. It is an important part of a High Definition
system and has copy-protection capabilities.
A badge to denote screens that can accept and display High Definition
pictures. To be HD ready, a TV must have a high-resolution screen -
with a minimum of 720p pixel resolution - HDCP and either a DVI-I/D or
HDMI socket. If a TV bears the HD Ready sticker, it is considered ready
to accept and display a high-definition signal, whether from a HD DVD
or Blu-ray player or from a digital broadcast.
This is the load a speaker brings to bear on an amplifier or its
electrical resistance. The higher the impedance – with 8ohms
being top – the easier the speakers is to drive or power, meaning
the speaker should work with lower power amplification, such as valve
designs. If a speaker has consistently low impedance – say 4ohms
– the speaker is much harder to drive.
A design that comes in a single box or a component that's
self-contained. As opposed to, say, a pre-amp and power amp combination
that would come as two or three separate boxes.
Flat screen displays that use Liquid Crystal Displays to create the
pictures. Commonly available in sizes from 14" - 60". Also known as
TFTs (Thin Film Technology). LCD screens come in a wider range of sizes
than say, plasma screens, and there is also a greater variety to choose
from. They generally have a much brighter screen, pictures tend to look
better under standard lighting conditions and they can often also
double as a PC screen.
LED TV is actually just a development of the conventional sleek LCD flat screens we all know and love. LED TVs are basically LCD TVs with one significant difference - they use Light Emitting Diodes (LED) to backlight the screen.
or line input
A component or analogue connection operating at 'line' voltage. If a
device has a line input it typically means that it is capable of either
amplifying or recording from an audio source. Dual phono (RCA) and
3.5mm headphone jacks are the most common form of connection.
The middle of the frequency range, that sits between the bass and
treble. The midrange handles most instruments and the human voice, so
is of particular importance to musical replay. Many hi-fi components
focus on accurate replay of the midrange at the expense of the rest of
the frequency range.
Motion Processing - Refresh Rate
The standard refresh rate on TVs sold within the UK is 50Hz. This is the number of times a second the picture is "drawn". Higher quality TVs later increased this figure to 100Hz and then 200Hz. The higher the refresh rate the less flicker you'll notice and the picture should be more "solid" in appearance.
More recently, manufacturers have begun using their own measurement systems of motion processing and can't necessarily be compared between brands. Examples include LG - Motion Clarity Index (MCI), Samsung - Clear Motion rate (CMR), Philips - Perfect Motion Rate (PMR), Sony - Motionflow XR and Panasonic - Intelligent Frame Creation (IFC). All these figures are twice or more of the traditional 100Hz/200Hz refresh rate figures. Higher figures should equate to smoother motion but remember to stick to individual manufacturers if you want to compare like with like. Plasmas generally use a 600Hz sub-field refresh rate.
coil, moving magnet
Types of phono cartridge. Remember, those things that sit in the groove
of a record to pick up the sound. Sometimes called a stylus. Moving
coil cartridges generally require a special phono stage and are the
The American system of TV broadcasting, this is not compatible with our
PAL system. So, if you are buying DVDs from America, you will need to
check that your DVD player/recorder is multi-region or has an
The measurement of electrical resistance, in hi-fi this is used to
measure the impedance of a speaker.
A technique invented by audio boffins to improve the quality of audio
replay. In essence it means generating more pieces of information
– or bits - from a waveform that has already been recorded. Very
PAL is the analogue broadcast system used in the UK, mainland Europe
and 120 countries around the world.
Active refers to a loudspeaker or subwoofer that includes some form of
amplification, which is often digital in nature, to power the signal
that is received from the crossover. The majority of loudspeakers are
passive, which means they need some form of amplification to work.
This means a computer can be plugged in. Simple really.
Phono (-stage, -input,
All things to do with a turntable refer to all things phono, and any
phono-stage, -input, -amplifier is similarly describing such vinyl
deliciousness. Phono cartridges work at very low voltages and require
additional amplification before reaching the line-level parts of a
An individual dot of a TV picture’s image. The more pixels, the
more detailed a picture is likely to be.
Pixel resolution – horizontal times vertical. Generally, the
greater the number of pixels, the more detailed the image.
Flat screen displays that use heated phosphors to create the pictures.
Screens most commonly come in sizes between 32" - 100" (smaller sizes
are available, but most often than not they are prohibitively expensive
to manufacture). Compared to LCD screens, plasmas offer better
contrast, a wider viewing angle, cope well with fast-moving action and
can display a wider range of the visible colour spectrum.
Normally this refers to a separate component that forms part of a
pre/power amplifier system. It will be the box with the meaty power
section inside it. Such systems keep sensitive pre-amp circuitry away
from such power amps as they emit lots of sonic nasties, although they
deliver all the wonderful oomph. That said, a power amplifier can be
found in any integrated amplifier as well, where they bung everything
together in one box.
Also sometimes known as a control amplifier, which gives a clue to its
purpose. The term pre-amplifier commonly refers to a separate component
that controls and routes signals coming from your source components. As
with a power amp, all integrated amps have to have a pre-amp section to
A way of delivering a superior, flicker-free image. That's all you need
to know for now. Seriously. You want more? Are you sure? Okay you asked
for it. By drawing all the lines that make up a frame simultaneously,
in one clean sweep - as opposed to drawing the odd lines and then the
even ones, alternatively, in separate frames, as its the case with
interlaced delivery - progressive scan offers a higher quality image
with more depth and a more stable appearance. Ha!
PVR (personal video
recorder)/DVR (digital video
Like the Sky+ box or Freeview equivalent, this piece of kit records
video in a digital format to a hard disk. As well as set-top boxes, PVR
technology is found in software, e.g. for personal computers, that
enables video capture and playback to and from disk. Some manufacturers
have started to offer televisions with DVR hardware and software built
in to the television itself. Most PVRs offer a choice of recording
modes, but the more capacity you want, the poorer the picture quality
(as with the LP and EP modes on VHS tapes). All hard-disk recorders
mean you can watch the start of a recording while the programme is
still being recorded (also called ‘Chasing playback’). In
essence, PVRs/DVRs are like HDD recorders, but with fewer features.
RDS, standing for the Radio Data System, arrived in the UK in the early
90s, adding a basic data and text service to FM radio, normally the
station name. RDS also enables traffic reports to be automatically
received by those listening to an RDS-enabled radio in their car.
An amplifier that also comes with a tuner on board. It is very rare to
see simple stereo receivers, although they are supposedly quite popular
over the pond. More frequently, such a combination is found on a home
cinema amplifier. In fact, the word receiver nowadays often simply
refers to a surround sound amp – with a tuner.
Time taken for screen to respond in milliseconds. A small figure
means that there is a quicker response time, giving images a cleaner,
clearer appearance with fast motion sequences.
Like DVD-Audio, this is another next generation audio technology, which
promised extremely high quality replay, allied to potential surround
sound mixes. And like its one-time competitor it hasn’t really
caught on. In fact, it’s quite hard to find SACD players these
days and when you do it is often on amazingly expensive machines that
now only offer stereo replay. Weird, huh. That’s not to say it
doesn’t work. Results can be spectacular, if you can find the
software. SACD uses a very different technology from CD or DVD-Audio,
implementing a one-bit delta-sigma modulation process known as Direct
Stream Digital, with the very high sampling rate of 2.8224 MHz. This is
64 times the sampling rate used in making compact disc, hence the
improved sound quality.
SCART used to be the most common standard for connecting audio-visual
equipment together. With its 21-pin adaptor, SCART was a nice simple
solution for carrying audio and visual signals. Previously, each of
these would have had their own socket, requiring numerous separate
connections and a spaghetti-type mass of leads. Somewhat usurped by
This refers to how efficient a speaker and, accordingly, how easy a job
the amplifier will have driving the speaker. Measured in decibels (dB)
at one watt electrical input (W) from one metre distance (m),
sensitivity ratings end up looking like this 90dB/W/m. But was this all
number jumbo mean? Well if the figure is above 89dB/W/m, the
loudspeakers will be a breeze to drive. If the figure is low –
anything below 87dB/W/m – get yourself a monster amp as the
speakers will need power aplenty to really sing.
This is the three dimensional audio picture a pair of speakers paint.
When correctly set up a system should create such a soundstage, where
sound doesn’t appear to emanate from the speakers themselves, but
around them, with musicians placed within this stage. A classic example
with current sound engineering is to have the lead vocalist positioned
centre stage, so his or her voice will appear to come from between the
An audio enhancement feature, TruBass enhances the perception of bass
frequencies to provide deep, rich bass response from any size speaker.
S-Video means separate video, which is a quality analogue video
connections. It carries the video data as two separate signals
(brightness and color). Many devices have both S-Video and component
video inputs (along with the composite video input). S-Video does not
carry audio on the same cable.
THX-certified gear conforms to the exacting standards laid out by
Lucasfilm, unsurprisingly headed up by George Lucas, he of Star Wars
fame. It is the trade name of a high-fidelity sound reproduction
standard for cinemas, screening rooms, home cinema, computer speakers,
gaming consoles, and car audio systems. These have recently been
separated into various standards, the premium being THX Ultra 2. The
THX system is not a recording technology, but mainly a
quality-assurance system.THX-certification means that there is a
high-quality, predictable playback environment that ensures that a film
sounds as near as possible to the intentions of the mixing engineer.
THX Ultra2 & Ultra2 Plus
THX Ultra2 is a 7.1-speaker extension of the original Ultra spec.
Ultra2 is designed to work well with multi-channel music and movie
presentations playing up to reference levels in rooms of 3,000 cubic
feet or larger. "Plus" adds volume control technology amongst other features.
THX Select2 & Select2 Plus
THX Select is a more affordable version of THX Certification. It is
designed to play at reference levels in rooms of approximately 2,000
cubic feet. "Plus" adds volume control technology amongst other features.
A fast, short signal such as a rim-shot that's a good test of a
Another sound technology, for audio and home cinema systems. For more
information look at the site of SRS Labs Inc. at: http://www.srslabs.com
The thing found at the top of most loudspeakers! The tweeter is a drive
unit that handles all the higher frequencies that need to be
reproduced. Often shaped like a dome, more fancy variations include
Having two PVR tuners means you can record two programmes, or watch one
and record the other.
All those extra new pixels on the latest HD screens are going to waste
when replaying a conventional DVD. So the latest DVD players can
upscale the original DVD signal produced, by filling in the gaps with
new information, to produce better pictures. Upscaling isn’t
quite HD DVD or Blu-ray – they cannot add detail that
wasn’t in the original recording – but it does boost
performance, thanks to the very complex algorithms used to create the
A measurement of power. In hi-fi parlance it tells you how powerful
your amplifier is or what power handling your speaker is capable of.
Remember power doesn’t always equate to quality. So a powerful
amp isn’t necessarily the best.
Wireless Fidelity is actually a certification of products to say they
meet certain standards for transmitting data over wireless networks. A
wireless network uses radio waves, just like mobile phones, televisions
and radios. The radios used for Wi-Fi communication are very similar to
the radios used for other devices. They can transmit and receive radio
waves, and they can convert 1s and 0s into radio waves and convert the
radio waves back into 1s and 0s. But Wi-Fi radios have a few notable
differences from other radios. Most importantly, they transmit at
frequencies of 2.4GHz. This frequency is considerably higher than the
frequencies used for mobile phones and televisions. The higher
frequency allows the signal to carry more data.
The driver in a loudspeaker that looks after the lower frequencies. In
most speakers – which are two-way designs – this is
actually a mid/bass driver.