Glossary

Please see a glossary of technical terms below.

ABR

For open environments sound quality can be further enhanced through the use of a sealed ABR (Auxiliary Bass Radiator). The ABR works like a piston moving back and forth generated by the movement of the air via the motion of the mid/bass driver inside the sealed cabinet. This makes the ABR ultimately act like a conventional port resulting in superior low frequency punch and extra penetration whilst keeping the elements at bay.

Acoustically Voice Matched

Ensuring that the many different loudspeakers used in a Home Cinema system have the same acoustic neutrality so that sounds blend seamlessly between them.

APC

Monitor Audio's engineers have developed a secret weapon called Automatic Position Correction. An integrated microphone measures irregularities caused by non-ideal room positions and uses a sophisticated Digital Signal Processor (DSP) to automatically adjust the system to deliver the ideal sound - this is achieved automatically each time you turn on the system at the mains.

ARC

Having various applications within a number of our speaker ranges, this high-tech Anti-Resonance Composite material is a thermo-set polymer loaded with minerals to provide very inert, optimally-damped components. Refined by Monitor Audio’s engineers initially for the Platinum series, ARC is ideal for acoustic design, where a high degree of structural rigidity and vibration damping is required in order to prevent the propagation of standing waves and modal resonances.

Bespoke Terminals

Platinum II’s terminal design is precision milled from solid copper with Rhodium plated conductor parts. Rhodium has been selected for its excellent electrical conductivity and resistance to oxidisation. Terminals are designed to accept a spade, 4mm banana plug or bare wire, up to 4mm in diameter (7AWG).

Bi-Amping

Each drive unit of a speaker is driven by a separate amp channel, so a pair of two-way speakers need two stereo amps and two runs of cable to each speaker.

Bi-Wiring

Some of the benefits of bi-amping but at a lower cost. You need speakers with two sets of inputs and a split crossover, then send twin runs of cable from amp to each speaker.

C-CAM Bass Drivers

Refined over many years by Monitor Audio, Ceramic-Coated Aluminium/Magnesium is used as a driver cone material for all our speaker designs from the mid-market models up. Originally developed by the aerospace industry for jet engine components, C-CAM's properties are ideal for loudspeaker cones being extremely rigid, yet light enough to yield high overall efficiency. C-CAM bass drivers are able to resist the bending distortion imposed by sudden and extreme bass excursions to reproduce very clean, deep and dynamic bass frequencies. Conventional cone materials are more likely to flex in operation, producing a significant level of audible distortion.

C-CAM Drivers

Ceramic-Coated Aluminium/Magnesium is a material originally developed by the aerospace industry for jet engine components. Its properties are ideal for loudspeaker cones being extremely rigid, yet light enough to yield high overall efficiency. In manufacture, aluminium/magnesium alloy undergoes a three-stage stress-relieving process to remove surface deformation and molecular weakness. Once formed, the alloy cone is subjected to a high temperature anodic coating process in which a layer of pure ceramic alumina is depleted onto its surfaces to a depth of 50 microns, producing a completely rigid sandwich of alloy and heat-dissipating ceramic material.

Conventional cones are liable to flex or twist in operation, producing a significant level of audible distortion. C-CAM cones have a much higher resistance to bending stress and therefore exhibit much greater fidelity over their entire operating range. C-CAM tweeters and woofers share an audible consistency producing a smooth transition of frequencies and a sense of realism and cohesion in the soundstage.

Cabinet Alignment

Defines the basic cabinet baffle structure whether ported or sealed (infinite baffle).

Colouration

A shift away from the natural rendition of music. Coloration is undesirable -'boomy' bass, a 'nasal' midrange or a splashy treble, for instance. All colorations tend to get in the way of the music.

CP

All Monitor Audio Controlled Performance in-ceiling/wall loudspeakers feature integral CP back boxes. These rigid, mineral-filled enclosures provide an ideal air load for the drivers, optimising midrange and bass performance while maintaining sonic consistency regardless of interior wall construction. The back box also retains the bass driver's backwave, limiting the transmission of sound to adjacent rooms.

Crossover Network

An electrical circuit used to split the signal into different frequency bands (splitting the signal into treble and bass for a two-way loudspeaker).

DCF (Dynamic Coupling Filter)

A new innovation in every driver replaces the usual rigid coupling of driver and voice coil with a pliable one. This ‘Dynamic Coupling Filter’ is a nylon ring ingeniously calibrated to be rigid up to the crossover frequency, and to act like a spring above it. In so doing the DCF helps to dampen surplus high frequency energy produced by the driver. It’s also perforated to encourage voice coil cooling and release air pressure from behind the cone for maximum driver efficiency. Result: more natural sound.

DCF is patented.

Decibel (dB)

Measures changes in sound pressure. A change of 1dB is just about audible, while +10dB sounds like the level has been doubled.

Dolby Pro-Logic

Uses an extra centre speaker at the front, which locks dialogue to the screen.

Dolby Surround

Encodes sound for rear effects channels into the stereo tracks. Needs to be replayed through a decoder to produce surround.

DSP

The DSP (Digital Signal Processing) allows fine tuning of all aspects of sound with complete control of the audio stream at high resolution. Advanced features include adaptive bass extension, highly accurate loudspeaker crossover and filtering, 3D audio processing, APC (automatic position correction).

Dynamic Range

The range, in dB, between the largest and smallest signals reproduced by Hi-Fi.

Frequency

High-pitched sounds have a high frequency, low-pitched ones a low frequency. Audible sounds range from around 16Hz to 20kHz.

Gold Dome C-CAM

The gold dome tweeter is formed from a ceramic-coated aluminium/magnesium alloy, gold anodised to a specific thickness for ideal stiffness and damping characteristics. Its new profile and surround geometry have been developed using advanced modelling tools, to provide the optimum qualities for accurate sound reproduction. The new design moves the first order of breakup to beyond 35kHz, producing a linear response way beyond audibility, which matches the wide frequency bandwidth available from HD music and cinema sound formats. The gold dome is thinner, lighter, more rigid and therefore more efficient than domes made from other materials which are prone to distortion in the audio band.

Hertz (Hz)

Unit of frequency. One Hz means a signal has one cycle per second.

Hi-Fi

Equipment that accurately re-produces audio within the range of human hearing.

Hive II Port Technology

A new type of port technology which uses a straight rifled design to accelerate air flow and reduce turbulence. HiVe II technology has the ability to move air in and out much quicker than a conventional port, the result is fast powerful bass coupled with superior transient response.

Home Cinema

The reproduction of audio with video material using extra loudspeakers to provide a 3 dimensional effect, to mimic the Theatre/Cinema experience.

IDC

The in-ceiling and in-wall LCR models employ a unique pivoting Inverted Dual Concentric midrange/tweeter module offering up to 18 degrees of play. This allows for the speakers to be discreetly positioned and the sound to be directed toward the listening zone by pivoting the IDC driver module to maximize performance. With the IDC module installed, these architectural speakers become true 3-way designs, offering superior performance and flexibility over typical 2-way or fixed angle speakers.

Within the proprietary IDC module an inverted 4"" midrange driver provides superior dispersion while enabling the midrange cone and tweeter dome assembly to be set as far forward as possible, allowing a clear acoustic 'sighting' of the desired listening zone and reducing undesirable diffraction effects. It's impossible to avoid diffraction effects from conventional two-way designs, which locate the bass driver 75mm (3"") to 150mm (6"") behind the speaker grille.

IEC Listening Room

Listening rooms designed with sound absorbent walls so as to give correct metre readings without echo or other audible interference.

Impedance

Electrical property. Low impedance draws a high current flow from the source, a high impedance draws little. So speakers with a low Impedance (lower than 6-8ohms) are more difficult for an amp to drive.

Magnetic Grille Fixing

Ultra-powerful Neodymium magnets hold the speaker grilles in place, allowing for easier installation and access. In-ceiling models offer the opportunity to use square and circular grilles for the ideal aesthetic result.

Mass Loading

The ability to add weight to the base of a speaker for fine tuning. The tuning is most apparent with the woofer or low frequencies.

Midrange

Frequency range where most of the instruments and voices are heard. Vital if singers, etc, are to sound natural.

MMP II

Metal Matrix Polymer driver cones have a polypropylene base loaded with metallic particles to offer a rigid and responsive structure. They are manufactured using a sophisticated high-pressure injection process, which modulates cone thickness at critical points to optimise stiffness and consistency, resulting in a superior sonic performance.

MPD (Micro Pleated Diaphragm) High Frequency Transducer

Developed over many months of intensive testing and listening, the MPD High Frequency Transducer is a landmark achievement by the engineering team for Platinum II. It represents an imaginative re-working of an existing technology, transforming a successful idea into an audiophile super-driver, having greater accuracy and efficiency than ever before. Using a new, proprietary low-mass pleated diaphragm with a surface area eight times larger than that of a traditional dome tweeter, the MPD transducer works like a super-fast accordion by rapidly squeezing the pleats to produce a smooth, wide, naturally fast response up to 100kHz. As a result it sounds more lifelike, releasing the high harmonic spectrum of every note without the distortion that blurs definition.

Ohm

Unit of resistance to current. Impedance of a speaker is measured in ohms. With lower impedance's, more sound pressure will be obtained from a given amplifier.

Power Handling

The maximum safe power for speakers. But be aware that it's easier to damage speakers with an amp of too low power driven hard, than that with too much power.

RDT

RDT is a unique technology developed specifically by Monitor Audio's engineers for the Platinum series of loudspeakers*. Designed to reduce mass and increase cone stiffness, RDT applies ultra-thin skins of C-CAM to a core of honeycomb Nomex®** material, creating a structure which is extremely light but incredibly rigid. At only 40 microns thick, the C-CAM skins are half the thickness of a human hair, yet when bonded to the Nomex core they form an RDT cone, which is 150 times more rigid than a single layer of 200 micron C-CAM alloy, but has a fraction of the overall mass. These properties allow the cone to operate as a lightning-fast piston for a clearer more natural sound. The RDT cone's concave geometry has been refined by FEA analysis to provide a smooth frequency response and to eradicate break-up.

* PLW-15's driver is C-CAM only

** Nomex® is a registered trademark of E.I DuPont de Nemours and Company

RDT II (Rigid Diaphragm Technology 2nd Generation)

A composite ‘sandwich’ structure made from ultra-thin low mass skins, bonded to a honeycomb Nomex® core material. It is very light and very strong, meaning that it can respond with great speed without bending - just like a perfect piston. RDT II uses C-CAM® for the front skin, while the rear skin is made from a woven carbon fibre material. We discovered that the new structure reduces distortion by over 8dB above 300Hz, which makes RDT II the lowest distortion cone technology in Monitor Audio’s history.

Ribbon Transducer

Monitor Audio's proprietary ribbon tweeter design uses an ultra-thin sandwich of C-CAM® alloy suspended in a powerful transverse magnetic field of high energy NeFeB rare earth magnets. The ribbon serves as both voice coil and radiating diaphragm, with every part of the ribbon driven directly and simultaneously without energy storage. Having a mass of just 18mg, its diaphragm is able to start and stop in an instant, producing a transient response capable of defining the leading edge and natural harmonic resonance of complex musical sounds. Specified to reach ultra-high frequencies up to an elusive 100 kHz, Platinum’s magical ribbon tweeter will reproduce with ease every last nuance and detail from vinyl, CD, DVD-A and SACD, together with the wider bandwidth of Blu-ray.

SPL

Sound Pressure Level

TLE (Tapered Line Enclosure)

The tapered and sealed internal enclosure for Platinum II’s mid-range drivers is cast from ARC material and designed to stop the formation of standing waves (internal sound wave reflections) in the cabinet. Result: greater midrange accuracy and reduced cabinet vibration for more accurate sound.

Tri-Grip Dog Fixings

All models feature a unique Tri-Grip fixing design. This 3-position 'dog' style fixing provides a greater contact surface area than other types, whilst saving installation time. The Tri-Grip fixings are made from a tough re-enforced polymer, giving a secure fixing without the risk of over-tightening.

Tri-Grip Dog Fixings are patented.

Tweeter

The speaker driver handling the treble.

Watt

Unit of power. More watts mean more power, but how loud a system sounds also depends on speaker sensitivity and room size.

Woofer

The large drive unit in a speaker to produce bass or low frequencies.