Glossary M-P

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Matrix Switcher

A switcher able to route any of its camera inputs to any of its monitor outputs; a name usually reserved for large systems, that often includes telemetry control.

Megabyte (MB)

1,048,576 bytes or 1,024 kilobytes. Used to measure computer memory. Sometimes used to mean 1 million bytes or 1,024,000 bytes (1,000 kilobytes). Also see Gigabyte.


The middle of the bass part of the frequency range, from approximately 50 to 100 Hz (upper bass would be from 100 to 200 Hz). Also used as a term for loudspeaker drivers designed to reproduce both bass and midrange frequencies.


The middle of the audio frequency range. Also used as a term for loudspeaker drivers designed to reproduce this range.


A device that converts electronic signals into the video image that was generated by the camera and lens. The picture end of a CCTV system.


Monophonic sound. One channel.


Having only one color. In television it is black and white.


MPEG-1 Audio Layer-3. Compression scheme used to transfer audio files via the Internet and store in portable players and digital audio servers.


MPEG is a video compression method commonly used in digital recording. MPEG-1 is a standard for CD-ROM video and audio. MPEG-2 is a standard for full-screen, broadcast quality video.MPEG-4 is a standard for video telephony.


System with multiple sources. Can also be used to describe a receiver that can provide multiple different sources into different rooms.


System that provides audio or video to multiple areas. Usually with only one source.


System that provides different sources into multiple areas simultaneously.



(National Television Standards Committee. See E.I.A.)
Color TV system used in the USA. CCTV


Undesired signal(s) that corrupts the original video signal and may reduce image quality.



The difference between two frequencies where one is twice the other. For example, 200 Hz is an octave higher than 100 Hz. 400 Hz is one octave higher than 200 hz.

Optical Digital Cable

Fiber optic cable that transfers digital audio signals as light pulses.

Output impedance

The impedance a device presents to its load.



Side-to-side movement of a camera (on a horizontal axis).

Pan/Tilt/Zoom (PTZ)

Indicates equipment with the ability to pan, tilt, and zoom, usually by remote user control. Much of PTZ equipment is completely integrated, meaning there is only one controller necessary to operate all three features.

Pinhole Camera

A pinhole Lens is only 1/16th of one inch in diameter, so cameras with tiny pinhole lenses can easily be hidden for covert video surveillance applications. Cameras with this type of standard lens are typically referred to as pinhole cameras.


A non powered element of a system.

Passive Radiator

A radiating surface (usually similar to a conventional speaker cone) that is not electrically driven but shares the same air space in a sealed cabinet with an electrically driven loudspeaker. This arrangement is functionally similar to a loudspeaker with a vented (ported) cabinet, with the passive radiator serving the duties of the air in the port.


An optional device that can enhance a CCTV system, for example, a multiplexer, VCR, photo printer, etc.


Picture in picture.


Picture element. The smallest cell or area of a CCD chip capable of displaying detail on a screen. The greater the number of pixels, the higher the resolution.


Flat-panel display technology that ignites small pockets of gas to light phosphors.

Power Amp

See Amplifier.

Power Output:

A measure, usually in watts, of how much energy is modulated by a component.


A control and switching component that may include equalization functions. The preamp comes in the signal chain before the amplifiers.

Pre Outs

Connectors that provide a line-level output of the internal preamp or surround processor.


Anything that processes an incoming signal in some way. Surround processors, for example, can decode a Dolby Digital signal to send to an amp so you can hear it.

Projection System

Display that projects image onto a screen.

Pulse Code Modulation: (PCM)

A way to convert sound or analog information to binary information (0s and 1s) by taking samples of the sound and record the resulting number as binary information. Used on all CDs, DVD-Audio, and just about every other digital audio format. It can sometimes be found on DVD-Video.

Progressive (p) scanning

A method of displaying images from a video signal on a television screen. With progressive scanning, the vertical lines on the screen are filled in sequentially, rather than in two passes as with interlaced scanning. Also see "interlaced scanning".


See Structured Wiring

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