Magnet

A device which has the ability to attract or repel pieces of iron or other magnetic material. Speaker magnets provide a stationary magnetic field so that when the coil produces magnetic energy, it is either repelled or attracted by the stationary magnet.

Magnetic Circuit

The circuit that includes the magnet(s), the top plate, and the pole piece; they combine to create a magnetic field in the air gap where the voice coil sits.

Magnetic Flux

The measurement of magnetic flux inside the air gap.

MECP

Mobile Electronics Certification Program is the only industry certification program recognized by both retail organizations and industry manufacturers. MECP is recognized throughout the country as the official certification for mobile electronics installers. The program is administered by CEA (Consumer Electronics Association) a division of the EIA (Electronics Industries Alliance). Virginia based EIA oversees electronics manufacture, repair, service and sales throughout the US. Most manufacturers and retail store owners are EIA, or CEA members. Introduced in 1991, MECP was immediately accepted by the electronics industry not only in the US but also in Canada. MECP certification even reaches overseas with many US and Canadian MECP certified installers enjoying a rewarding career away from home. Mobile Dynamics is an official test site for MECP.

Memory

The word most commonly used to refer to a system's ability to retain specific information.

Memo List

A Custom File feature that allows the user to toggle through the disc or station titles currently loaded without interrupting playback of the existing disc or station.

Metal Tape EQ

An equalization circuit that compensates for the unique frequency response characteristics of metal tape.

Microprocessor

A semiconductor that can be programmed to perform a variety of tasks in many different systems.

Middle Frequencies

The frequencies above 400Hz but below 4 kHz.

Midrange Driver

A loudspeaker specifically designed to reproduce the frequency in the middle of the audible bandwidth. Most musical energy lies in the midband.

Midwoofer

A speaker that is designed to reproduce the upper bass frequencies, typically between 80Hz and 200Hz. Small subwoofers are often used as midwoofers in order to integrate a larger woofer, or add midbass "punch".

Milliamps

A unit of measurement of electric current equal to 1/1000th of an ampere. The milliampere is the most common unit used when measuring quiescent current drain.

MIN

The cellular phone's Mobile Identification Number.

Mineral Filled Co-Polymer Cone

A very light and rigid cone material that combines high strength and exceptional damping characteristics. JBL uses this on the GTx subwoofer line for high SPLs and excellent transient response.

MIN 1

The 10-digit mobile number used in cellular telephones.

MIN 2

The three-digit area code used in cellular telephones.

Mixer

At its simplest level, an audio processing device used to add (combine or sum) multiple inputs into one or two outputs, complete with level controls on all inputs. From here signal processing is added to each of the inputs and outputs until behemoth monsters with as many as 64 inputs are created

Mms

The mechanical mass of a loudspeaker diaphragm including air load.

Moderate Q Design

Used in subwoofers, this design delivers high output at cutoff in small sealed enclosures.

Module

A term commonly used to describe a self-contained part or device that can perform a specific function.

Mono

The operation of an amplifier in one channel for both input and output. Can refer to an amplifier with only one channel of amplification.

MOSFET

Metal Oxide Semiconductor Field Effect Transistor - A form of field-effect transistor controlled by voltage rather than current, like a bipolar transistor. MOSFETs have a significantly higher switching speed than bipolar transistors. They generate almost no loss (little heat generation), which lends the power supply fast response, excellent linearity, and high efficiency.

MOSFET-Power Supply

A power supply that employs MOSFET (Metal Oxide Semiconductor Field Effect Transistor ) transistors to convert DC to AC. Offers superior thermal stability and more accurate switching.

Mounting Depth

The amount of physical space required to mount a Driver without having any of its parts touch objects below. This is particularly relevant to car speakers where such mounting spaces may be sharply limited as to their ability to accommodate deep speakers with large magnets. Door panels are a typical example of where care must be taken in selecting speakers to be mounted.

Mounting Ring

Often used to describe the circular gasket seal incorporated into the edge of a speaker, traditionally the term "mounting ring" refers to a separate device placed between a Driver and the surface on which it is mounted, for the effect of raising the speaker so that larger and deeper speakers can be accommodated in limited spaces.

MP3

MP3 Stands for MPEG (Moving Picture Experts Group) Audio Layer 3. Mp3 is a format which "compresses" (if you will) data from a normal cd, thus making it smaller in size (Megabytes) therefore enabling the user to have more songs on a cd that the usual format (CDA).

MTSO

Mobile Telephone Switching Office - The main office of the cellular network that holds all the information for matching a customer's mobile number and electronic serial number, and hardware and software for controlling the cell sites.

Multimeter

A common term used to describe a VOM. A multimeter usually has the ability to measure volts, ohms, and amperes or milliamperes.

Multiple Power Supplies

Putting more than one power supply in an amplifier. JBL will often use multiple power supplies on large amplifiers to improve performance in difficult situations.

Mute

A control found on receivers, some mixers, and certain signal processing units that silences (mutes) a signal path, or output.

Mylar®

An extraordinarily strong polyester film that grew out of the development of Dacron® in the early 1950s. During the 1960s cellophane gave way steadily to Mylar® with its superior strength, heat resistance, and excellent insulating properties. The unique qualities of Mylar® made new consumer markets in magnetic audio and video tape, capacitor dielectrics, packaging and batteries possible.