Glossary

Everything you wanted to know about Music and HiFi but were afraid to ask

The aim of this section is to provide straightforward information without any BS!
Its a glossary so we’ve tried to do things in alphabetical order, so scroll down until you find what you are looking for.

Most items will open a simple window box but those items that have “opens in a new tab” will open a separate page/tab in your browser.

If anyone has a term they want to know more about and would like us to add an explanation on this page then please contact us using the contact form here.

We will be constantly updating this page as new terms are added so watch this space.

A

Aa-Ad

Ae-Ai

Aj-Az

B

Ba-Bd

Be-Bi

Bj-Bz

C

Ca-Cd

Ce-Ci

Cj-Cz

D

Da-Dd

dBu

dBv

De-Di

Decibel (opens in new tab)

Dj-Dz

E

Ea-Ed

Ee-Ei

Ej-Ez

F

Fa-Fd

Fe-Fi

Fj-Fz

G

Ga-Gd

Ge-Gi

Gj-Gz

Gramophone

H

Ha-Hd

He-Hi

Hj-Hz

I

Ia-Id

Ie-Ii

Ij-Iz

J

Ja-Jd

Je-Ji

Jj-Jz

K

Ka-Kd

Ke-Ki

Kj-Kz

L

La-Ld

Le-Li

Lj-Lz

M

Ma-Md

Me-Mi

Mj-Mz

N

Na-Nd

Ne-Ni

Nj-Nz

O

Oa-Od

Oe-Oi

Oj-Oz

P

Pa-Pd

PCM

Pe-Pi

Phonograph

Phono Plug

end

Pj-Pz

Q

Qa-Qd

Qe-Qi

Qj-Qz

R

Ra-Rd

Re-Ri

Rj-Rz

S

Sa-Sd

Se-Si

Sj-Sz

S/PDIF

end

T

Ta-Td

Te-Ti

Tj-Tz

U

Ua-Ud

Ue-Ui

Uj-Uz

V

Va-Vd

Ve-Vi

Vj-Vz

W

Wa-Wd

We-Wi

Wj-Wz

X

XLR

Y

Ya-Yd

Ye-Yi

Yj-Yz

Z

dBu
Audio level measurement

dBu is a measurement system used in Broadcasting and professional audio level measurements in the UK, Europe and other parts of the world.

The “u” indicates that this measurement is an actual level rather than a ratio or percentage.

The “reference” level (0dBu) is 0.775v RMS. This level is explained in more detail under Decibel (dB)

Powered by
dBv
Audio level measurement

dBv is a measurement system used in Broadcasting and professional audio level measurements in America, Japan and other parts of the world.

The “v” indicates that this measurement is an actual level rather than a ratio or percentage.

The “reference” level (0dBv) is 1v RMS.

VU (volume unit) meters usually use the dBv scale

Powered by
Gramaphone
Audio Equipment (vintage)

The Phonograph, Thomas Edison’s original sound recording device using a stylus (needle) and a Cylinder covered in tinfoil was further developed by Bell labs and renamed the Gramophone.

In the 1890’s Emile Berliner replaced the cylinder with a flat shellac disk which allowed a greater recording time and was far more practical than a cylinder.

The gramophone disk originally rotated at 78 rpm (revolutions per minute) but in the 50’s the two modern “long play” formats were developed running at 45 or 33 rpm using either 7 inch (single) or 12inch (LP) vinyl disk which were easily produced cheaply and in large numbers.

There was also a 16rpm small disk which was primarily used for low quality voice recordings (like war reporting for radio news) but they were soon replaced by magnetic wire and tape recorders.

This basic principle is still used today as modern record players and “Vinyl”  is much loved by serious music fans

Powered by
PCM (Pulse Code Modulation)
Digital Audio

PCM or Pulse Code Modulation is a way of converting analogue audio into a digital form.

A PCM analogue to digital converter (ADC) samples the voltage of the audio signal at a steady “sample rate” which is at least twice the frequency of the maximum audio frequency that is likely to be converted.

Each sample is converted to a binary “number” which can be sent to a digital system one after the other in whats called a bitstream.

The more “bits” that the ADC is capable of will produce a higher resolution signal with less noise when converted back to analogue audio.

A 16 bit converter (CD) can convert a signal to any of 65,536 numbers.

A 24 bit converter can convert a signal to any of 16,777,216 numbers.

See “Digital Audio” for more information.

Powered by
Phonograph
Audio equipment (vintage)

The Phonograph was Thomas Edison’s original sound recording device where a stylus (needle) was attached to A moving diaphragm turned the sound waves into mechanical movement.

A stylus (needle) was attached to the diaphragm and cut a groove into a rotating cylinder covered in tin foil (later wax) which also moved the stylus along its length. The sound waves changed the depth of the groove thus recording the sound on the cylinder.

To replay the sound the stylus was returned to the start of the groove on the cylinder and the stylus then used the diaphragm to change the changing depths of the groove back into sound which was amplified by a large horn,

The Phonograph was further developed by Bell Labs (Alexander Graham Bell) and became the Gramaphone.

Powered by
Phono (RCA) plug
Audio Connector

The RCA plug became popular in the UK in the 1970’s for turntable connections and it became known as the “phono” plug.

The phono plug is now pretty much the standard analogue audio connector for domestic music systems. around the world.

Phono plugs are also used for coaxial SPDIF digital cables.

Powered by
S/PDIF
Digital Audio interface

S/PDIF stands for Sony / Philips Digital InterFace and was the first domestic digital connection system used with CD players and Digital recorders .
S/PDIF used two types of cable and connector.

Coaxial – An electrical connection using coaxial screened cable usually with phono (RCA) plug connectors.
The coaxial S/PDIF interface would work with normal analogue audio leads for short lengths but because it is an electrical connection it can generate noise and hum loops in music systems.

Optical (TOSlink) – This connection system used a fibre optic cable with special connectors.
There is no electrical connection so there is no danger of inducing noise and hum into the analogue circuits.
In the early days of digital audio TOSLink lasers were not capable of running higher data rates but these days optical performance is probably better than coaxial cables

Powered by
XLR
Audio connector

The XLR connector is a very robust professional connector and is used extensively in broadcast and professional systems around the world.

XLR connectors have between 3 and 8 pins.

The 3 pin is used for balanced audio both at line and mic level and is often found on high end audio equipment

The 4 pin version is often used for 12V power on professional audio and video equipment.

The 5 pin version is used for digital control (DMX) from lighting desks to lamp faders

The other pin configurations are used for specialist connections.

There is also a miniature “tiny” XLR connector but this connector is not as common as its bigger brother

Powered by