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Tech Talk

Active Impedance Correction

Active Impedance Correction (AIC) is an innovative extension of former known ways of reducing distortion in electrodynamic loudspeaker drivers. The effect of AIC is a clearer midrange with a markedly reduced roughness, especially noticeable on voice reproduction. In figures, this amounts to a reduction of third order harmonic distortion in the order of 6dB (= 50% reduction).

Impedance and Tweeter Level

All Kevlar Series speakers are provided with switches for the tweeter and the impedance. The switches are placed on the front of the speaker, behind the grille, for easy post installation fine-tuning to any speaker set-up and listening environment.

Asymmetric Cone

The Kevlar woofer has an asymmetric cone where the cone is convex on one side and concave on the other. This shape angles the sound away from its normal 90° dispersal pattern. This creates optimal bass dispersion as there is no direct interference from the enclosure itself.

Auto On/Off

This feature automatically switches the subwoofer on when it receives a sound input signal and sets it in stand-by again after approximately 20 minutes without an input signal. So, basically this allows you to forget all about the subwoofer once it is connected.

BASH Amplifier

This subwoofer features the highly efficient BASH® amplifier technology, which combines the musical quality of class A/B amplifiers with the efficiency of class D amplifiers. BASH® technology translates into more efficient, yet more powerful amplification without the heat associated with conventional amplifiers.

Bi-wiring

This speaker is prepared for optional bi-wiring, and bi-amplification, for truly high-end performance.

Boundary Gain Compensation

The Boundary Gain Compensation filter compensates for the room influence at low frequencies, as any room amplifies the lowest frequencies. The magnitude of the room?s amplification depends on the room size and where you are positioned in the room. Normally, it increases the closer you get to a wall. This can result in too high a bass level from approx. 60Hz and increasing downwards - in the range between 20-30Hz it peaks up to 5-10dB in an average room! At first this could sound really impressive, but the sound quickly begins to sound ?boomy?, especially when listening to music, and rather annoying. So the Boundary Gain Compensation ensures a very linear in-room bass response and gives you more flexibility when it comes to placement and choosing your favourite listening position.

Cabinet shape minimizes standing waves

Minimizing standing waves in cabinet is always a major issue when creating a speaker. The sound radiation from the rear face of the diaphragm causes sound waves to bounce back and forth inside the cabinet. If these reflections hit the diaphragm again, the result is a coloured and unclear sound. Thanks to the shape of the A 7 cabinet, standing waves are kept down to an absolute minimum. By creating a multi-curved, multi-angled cabinet, internal sound waves are prevented from bouncing back and degrading the loudspeaker?s performance.

Central Control

The product is part of an integrated system and therefore allows you to utilize all your centrally placed electronic sources in any room. This means that, for example, you can use your CD-Player from your living room to listen to music in the kitchen or even put on a DVD and enjoy movies anywhere in the house with the right modules and accessories.

Centre Plug

The Centre-Plug replaces the traditional dust cap, making the cone both lighter and more responsive, while also cooling the voice-coil resulting in higher power handling and a stable sound reproduction when playing loud. The design produces increased power-handling capabilities along with a more uniform, precise and dynamic reproduction of sound. The Centre-Plug also prevents potential break-up points where the dust cap would have been glued to the cone. In addition, it prevents over- and under-pressure behind the dust cap when the cone moves back and forth. The advantage is more dynamic and precise sound reproduction.

Class D digital amplifier

The power is delivered by a class D digital amplifier, chosen because it is much more efficient than conventional amplifiers - it simply produces more sound and less heat. And with lower power consumption the need for cooling is significantly reduced which again reduces the size of the heat sinks. Also the circuitry layout itself is more compact which besides space savings also grants shortest possible signals paths and thus optimum sound quality. A digital amplifier is not a cheap solution, but it is the right solution in order to decrease the size and enhance the performance.

Coaxial drive unit

The co-axial drive unit (a tweeter integrated into the mid/woofer) ensures the same acoustic centre for the two drivers and thus the treble and bass frequencies reach your ears in correct acoustic phase (simultaneously) regardless of whether or not your listening position is off-axis ? horizontally or vertically.

Convex tapered vent

When playing loud the speed of the air in the bassreflex port can create sonic colouration via turbulence which is why the design of the ports is highly critical. The carefully symmetrical-flared design (Convex-shaped) of the Jamo bassreflex port ensures an optimised airflow that minimizes port noise. Actually, this design allows the speaker to generate 5dB of extra SPL before any port noise occurs!

Crossover

The subwoofer can be set to only allow frequencies above 150Hz, the upper frequency the subwoofer handles, to be distributed to the satellite speakers.

Daisy-Chaining

It is supplied with line-in/line-out connections to enable the daisy-chaining of multiple units.

Dipolar

Dipolar means the sound is distributed from both the front and rear of the speaker ? in opposite phase. The reason for using dipolar surround speakers is not that you should be able to pinpoint their physical location; on the contrary, they should add a ?3D? ambience to the surround effects, making you feel part of the action.

A dipolar front speaker?s sound radiation will emerge from the back and bounce from the rear and side wall before reaching your ears, creating a slight delay in the sound from the front and back. The 2nd order reflections adds ambience and gives you the impression of a much larger room. A dipolar front speaker is to be angled in slightly from the rear wall. Due to the angling the rear sound will be bouncing off two boundaries before reaching your ears. The reflections add ambience and gives you the impression of a much larger room.

DivX

DivX is to movies what MP3 is to music ? Thanks to very efficient compression algorithms, a full movie can be stored on just one CD-ROM.

Dolby Virtual Speaker

Dolby® Virtual Speaker technology simulates a highly realistic 5.1-speaker surround sound listening environment from as few as two speakers, making it an ideal technology for digital TVs, stereo minisystems, PCs, and a variety of consumer audio/visual products. Dolby Virtual Speaker technology also creates a wider two-channel environment during playback of stereo CDs and MP3s, and when combined with Dolby Pro Logic® II processing, (for example, in an audio/video receiver or PC), delivers a virtual surround listening experience from any high-quality stereo source.

Down-firing woofer

This unique feature minimizes one of the major barriers to good sound reproduction. To avoid boomy bass reproduction, loudspeakers must normally be placed well away from the wall ? often impractical in many living rooms.When a woofer fires downwards it couples with the floor, making placement less critical. In other words, this speaker can be placed close to the wall.

DTT

DTT (Decoupled Tweeter Technology) is a mounting system specially developed by Jamo. One of the biggest challenges when designing speakers is preventing unwanted cabinet vibrations from clouding or colouring the sound. High frequencies are particularly susceptible. This problem is solved using the ingenious Jamo DTT.

By decoupling the tweeter from the rest of the loudspeaker, vibrations transmitted from the front baffle to the tweeter are reduced by more than 20dB, resulting in an uncommonly detailed and realistic reproduction of high frequencies.

Dual concentric diaphragm

The totally unique tweeter features a clamped dual-concentric diaphragm and ventilated magnet system. Among other benefits, this extends the frequency range to a very low 1 kHz, allowing a smooth and seamless transition with the midrange, and then all the way up to 40 kHz,making it compatible with new digital multichannel sound formats. The voice coil is copper-plated aluminium wire, combining the low weight of aluminium with the superior conducting qualities of copper, and making magnetic oil for cooling and resonance damping unnecessary.

Dual Voice-Coil

The unique Dual Voice-Coil design allows both left and right channel sound from just one speaker. Simply hook up both the left and the right channels to the special terminals on the speaker. Hook up one channel only, if the speaker is to be used in a conventional stereo set-up.

Electronic overload protection

An electronic PTC resistor automatically limits power to the loudspeaker if it becomes overloaded.When the volume is turned down again, the resistor cools down and the sound is restored to its normal level.

Flexible & Expandable

Being a part of a modular system makes the product flexible and expandable by nature. This will, facilitated by and combined with leading technology, allow you to easily adapt the system for your entertainment requirements by simply adding modules as needed, and because the system allows distribution in up to 16 main-zones and 16 sub-zones, it ought to meet the requirements of any home.

Front baffle

The 1.7in/43mm thick front baffle is made from no less than seven layers of MDF board, glued together and shaped under high pressure. The rounded shape provides optimum working conditions for the drivers as it prevents diffraction and improves rigidity even further.

The baffle itself is attached to a 57lb/26kg cast-iron base housing the cross-over network and the bi-wiring XL binding posts, they connect directly to the crossover network placed inside the base, so securing the best possible signal path. A solid double 5x60mm stainless steel brace with a special damper ensures a rock solid connection between the baffle and the base.

Gold plated binding posts

To ensure loss-less connection, the terminals are equipped with goldplated binding posts, accepting stripped wire as well as spades, pins etc.

HCC (Hard Conical Cone)

The HCC technology (Hard Conical Cone) enables the driver to reach far beyond midrange frequencies before any significant cone break-ups occur. The material?s rigidity and the cone?s conical shape ensures the unit creates clear and detailed sound with very little distortion, even at high sound pressures. This combines with the natural rubber suspension, which effectively prevents vibrations from travelling back to the diaphragm; the result is a very well-controlled diaphragm that operates vwithout break-ups up to 4kHz -well beyond its working range.

HDMI

HDMI (High-Definition Multimedia Interface) is the first and only industry-supported, uncompressed, all-digital audio/video interface. By delivering crystal-clear, all-digital audio and video via a single cable, HDMI dramatically simplifies cabling and helps provide consumers with the highest-quality home theater experience. HDMI provides an interface between any audio/video source, such as a set-top box, DVD player, or A/V receiver and an audio and/or video monitor, such as a digital television (DTV), over a single cable.

Integrated flexible mounting bracket

Being able to control the directivity of sound is of paramount importance in an indoor/outdoor loudspeaker. It?s easy enough to position it correctly on first installation but what if you want to change the speaker?s alignment afterwards? If you have invested in a Jamo Indoor/Outdoor A2 design there?s no problem. Thanks to its ingenious mounting bracket you can adjust the speaker in both horizontal and vertical planes, a strong allen-key bolt allowing secure ?locking? in position.

Kevlar Woofer and Silk Dome

The Kevlar material is one of the very best materials for designing woofers. Utilizing the Kevlar material in combination with our silk dome tweeters, provides exceptionally clear and rich sound performance.

Level, Phase and Cut-off

Continuously variable level, phase and cut-off frequency controls make it easy to tune the subwoofer to integrate with virtually any speaker on the market, as well as allowing different placements and personal preferences

Limiter

A limiter prevents high input signals from overloading the subwoofer amplifier. It guarantees that the subwoofer will always be fully in control and that the sound will remain clean and clear, no matter how hard the subwoofer is driven.

Low-loss X-over

At Jamo, we design all our loudspeaker units in-house.This means individual units for exact purposes and units that complement each other perfectly, thus reducing the need for complex crossover filters with various compensation circuits. Limiting the number of components in the filter also reduces Its power consumption (an overly complex filter can easily consume 10 - 20% of the power supplied).The advantage of lowloss x-overs is clearer, cleaner sound reproduction, as well as lower distortion and higher sensitivity.

Magnetic shielding

Normally when placing a loudspeaker close to a TV, the magnets of the drive units will cause discolouration of the TV picture. Therefore centre channel speakers ? which in order to achieve best possible coherence between picture and sound, need to be placed as close to the TV as possible ?must feature shielded magnets to eliminate the disturbing magnetic radiation.

MFB (Motional feedback)

When a large woofer has been abruptly driven by a strong sonic impulse such as an explosion or a timpani, the woofer continues moving after the impulse stops.The MFB circuit compares the impulse to be reproduced with the actual movement of the woofer. If the woofer moves unnaturally in relation to the input signal, the MFB circuit corrects the error before it becomes audible. Furthermore, the MFB makes it possible to equalize the subwoofer to go deeper without losing any precision.The result is incredibly accurate, deep bass, full of punch and dynamics.

Midrange

In order to fulfill the R 909 brief we also had to use state-of-the-art technology for the midrange driver. Employing a patented Neodymium magnet arrangement, the Seas unit uses a magnesium cone for its stiffness and low weight, both vital qualities for dynamic response. Thanks to the HCC (Hard Conical Cone) technology the driver is able to reach all the way to 9kHz before any significant cone break-ups occur. This makes for extremely low distortion throughout the range plus a very open and detailed midrange for optimum voice reproduction. Turned from solid brass the centre-plug has a cooling effect on the voice-coil, providing greater power-handling capability and most importantly, extra sonic stability when playing at high volume levels.

Multiple drive unit attachment points

The drive units have been clamped to the rear part of the cabinet in addition to the front baffle. This enables them to stay perfectly still, eliminating microscopic vibrations created by the sound and the movement of the drive units themselves, thus improving the overall sonic performance. In addition, the clamping of the drive units front and back also adds additional internal bracing, adding further to the excellent acoustic properties of the rigid aluminum cabinet.

Mylar Tweeter

The Mylar tweeter does not only feature great sonic qualities, it is also moisture-resistant, making the speaker ideal for installation in moist areas (such as a garage). However, only the Indoor/Outdoor Series is designed for full outdoor use.

Neodymium magnet

Neodymium is a powerful magnetic material ? 10 times more powerful than a normal magnet. Because the magnet can be reduced in size, it can typically be placed inside the voice coil of the loudspeaker unit, allowing the magnetic force to be converted around the voice coil ? exactly where it is needed.

Paintable Frame and Grill

Both the frame and grille can be painted for perfect integration with the surroundings. We recommend using a spray paint. Separate the grille and the frame from the speaker and paint them individually. Then while the paint on the grille is still wet, gently blow air through the grille from the one side in order to clear all the small metal holes of paint.

Pivoting Midrange and Tweeter

The pivoting tweeter and midrange can easily be directed toward the sweet spot in any listening area, providing the best possible listening conditions.

Pivoting PEI Domes

The left and right channel PEI domes are especially designed to cope with damp and moist conditions. Also, the pivoting tweeters can easily be directed toward the listening area, providing the best possible listening conditions.

Pivoting Tweeter

The pivoting tweeter can easily be directed toward the sweet spot in any listening area, providing the best possible listening conditions.

Polypropylene Woofer

The speaker has a Polypropylene woofer which delivers a very smooth, well-extended bass response.

Protection Circuitry

The amplifier is incorporates both thermal and short circuit protection.

Signal sensing

The unit offers automatic on/off-functionality based on if there is any signal provided to the amplifier or not. The signal sensing can, if desired, be deactivated.

Simplicity of Installation

An integrated system allowing simple operation of multiple sources to multiple rooms might sound complicated in terms of installation. However, this is not the case. As illustrated in the diagram, there are only a minimal number of wires connecting the modules, which is partly due to the versatility of the CAT5e cables used in the installation, making the system quick and simple to install.

Slotted Port Cabinet

Slotted port cabinet construction allows for deeper tuning, superior power handling and distinct sonic fidelity. Last but not least, the integrated port design ensures great rigidity and stability in the cabinet design.

Speaker Level In

This subwoofer features speaker-level inputs, which is vital if your amplifier/receiver lacks a subwoofer line output.

The subwoofers also have both left and right line-level inputs (for stereo sources) plus a "loop-through" capability to allow the signal to be routed through to a second subwoofer. Spikes

The easily adjustable spikes ensure that the speaker always stands securely, making a good mechanical contact to the floor. The speaker can also be placed on the rubber supports, if required.

Temperature Range

The speaker can handle a very wide temperature range of -10°C/-14F to +70C/158F.

THX Ultra 2

THX Ultra2 Certified.The most stringent quality requirements for home cinema in the world, compiled by LucasFilm. The THX certificate is your guarantee of high, uniform quality throughout the entire frequency range, clear and well-defined dialogue, accurate location of music and sound effects and, not least, effortless and realistic dynamics in reproduction ? from the softest whisper to thundering explosions. A THX-certified system in your own home will offer the same level of sound quality sound that?s available in ?professional? cinemas.

Tweeter

There was only one choice when it came to choosing a tweeter to reproduce the delicate treble frequencies? the legendary Revelator from Scan Speak. However, since this model features a relatively large face-plate, it would have needed to have been placed further away from the midrange than would be ideal. So, in order to obtain a seamless transition with the midrange driver, we chose to fit a smaller cast-alloy face plate.

The tweeter features a 1in textile dome which is coated several times to obtain a unique combination of dynamic linearity and resonance damping, the result being an incredibly smooth, linear, dynamic and incredibly transparent sound.

The driver's Symmetric Drive Technology - a copper ring on the pole that extends past the voice coil, curving into the dome chamber - practically eliminates electrical phase shift. And, just as it does with the midrange, it also lowers distortion significantly.

To eliminate turbulence the double-damped, optimized chamber behind the magnet system is also equipped with an anti-resonator-plug. And the specially designed chamber under the cloth surround minimizes air noise and compression. Actually this tweeter is so carefully manufactured that damping unwanted resonances using ferro-fluid - the usual way - is rendered unnecessary!

WaveGuide

WaveGuide is the unique way Jamo has shaped the tweeter?s faceplate. The result is a controlled sound pattern with a more open and dynamic reproduction of sound. WaveGuide makes it easier to position the speakers in the room.

Another big challenge is to secure a uniform dispersion pattern in the treble and midrange frequencies. In general, the dispersion is getting narrower as the frequencies get higher. Consequently in the area where the mid/woofer and the tweeter should integrate smoothly, the mid/woofer has a narrow dispersion and the tweeter has a wide dispersion. This problem is solved with the Jamo WaveGuide. The completely smooth design of the WaveGuide also reduces diffractions to an absolute minimum. Finally, the WaveGuide increases treble output in the lower treble range, which means the tweeter needs less power for the same SPL. So, power handling is improved and distortion is reduced.

Wide Frequency Span

With the advanced 4-way design, this loudspeaker provides amazing sound through out an extraordinary wide frequency span.

Woofer

Most woofers are developed to work in a cabinet, and as a woofer constructed for a dipole application is very different from a traditional boxed one we had to develop a special woofer for this open-baffle application.

These huge bass drivers employ high quality magnesium baskets plus lightweight, air-dried paper cones with a rubber suspension. The time-consuming process of letting the cones air-dry ? instead of just pressing out the water in the former - has resulted in a thicker, and thus more rigid, material for the same low weight. Although paper cones might be out of fashion in some circles they have the ability to start/stop moving incredibly quickly, can reach very, very deep and they endow the drive unit with great sonic precision and musicality.

X-over

As should be apparent from the drive unit descriptions, we wanted to start out with drivers of immense fundamental quality, precisely so that we would only need minimal assistance from the cross-over!

Consequently, the cross-over in the Jamo R 909 is of a relatively simple ? in the most positive sense of the word ? low-order configuration. The advantages of using the 2nd order filters that are in the R 909 is that both electrical and phase angles are kept at very small values, something that's of great importance both in terms of sound quality and the eventual load on the amplifier. The use of quality Solen foil-capacitors and air-coils in the crossover further ensures sound quality.

XBR (eXtended Bass Response)

With the unique Jamo XBR (eXtended Bass Response) feature, the surround loudspeaker functions as a dipole in the treble and midrange, and as a bipole in the lowest bass, providing the diffuse surround reproduction of traditional dipole loudspeakers, but with full bass reproduction.