Glossary

Not all visitors to the earplug site are sound engineers so we have included a glossary to explain some of the terms used in this website:

Soundman

A non-sexist word to describe the slightly harrassed looking individual (male, female or non specific) who is usually to be found still working during all of the meal breaks on a t.v. or film set or backstage somewhere, trying to get the final vital parts of the rig working. They perform many thankless tasks providing the sound coverage and the communications for the production. They are usually not noticed by anyone else on the crew unless something doesn't work! (I speak with the benefit of 30 years of hindsight)

Phantom Power

A D.C. supply usually generated by a sound mixing desk and applied to pins 2&3 of an XLR cable. The Voltage is measured between pins 2&3 and ground (pin 1) and is standardised at 48 volts. It is used to power microphones.

Line Level

A signal measured at '0'dBm which is 0.775 Volts peak to peak into an impedance of 600 Ohms.

Mic Level

The usual definition of Mic Level is -60dBm or 1mV; peak to peak into an impedance of 600 Ohms. In the earplug the standard has been changed to -40 dB as this is a more realistic level to set the gain of a mixer channel for test purposes. We have also included an intermediate level of -20dB.

One Legged

A term used to describe a balanced cable which has one of its signal conductors (on Pins 2&3) disconnected.

Earth Lifted

Cables have the screen or ground conductor disconnected either accidentally or deliberately. Phantom power will not work along this type of cable!

BBC PPM Meter

An Industry wide standard level meter which displays the following characteristics:

   Response of 1dB down from steady state for a 10ms tone burst
   Response of 4dB down from steady state for a 3ms tone burst
   Return time of 1.5s to -20dB

The LED PPM in the earplug emulates this response electronically to give a fairly accurate Peak Reading Meter.

4 Wire

An Industry Standard communications circuit that uses 1 balanced pair to talk in each direction.

Howl round

Also known as feedback is a term used to describe the squealing sound that results if a microphone is put too close to a loudspeaker that is carrying the sound of the microphone. Actually the microphone and loudspeaker don't even have to be in the same country let alone the same room as the effect is due to the gain in the system and the howlround of a satellite communications circuit is something to be avoided!

LBL Technology

The earplug features LBL technolgy which is a "Little Blinking Light" that flashes when the battery is good and stops flashing when the battery is nearly flat. It also helps you to find the earplug if you have put it down somewhere. The LBL light is mounted on the top surface of the box so if you have put the earplug in your pocket whilst it is still switched on, hopefully someone else will see the flashing light and inform you before the battery is exhausted.

LRF Support

It was hoped to provide LRF (Little Rubber Feet) support on the Earplug but alas this was not possible as they fell off when you put the unit in your pocket.