Monitor Audio debuts Radius HD speakers

Phil Hinton

Staff member
After a five year reign, the original compact 'audiophile' sub/sat speaker range gets a make over, here is the press release.

Promising even more style, practicality and performance than its famous forerunner, Radius HD is a new decor-matching range of ultra-compact
sat/sub speakers, which replaces the celebrated and acclaimed Radius series. So successful were these radical originals that it’s taken Monitor Audio five years to improve them. But with sharp new styling and driver technology, easy-fit brackets, luxury finishes and even better performance, Radius HD
marks a comprehensive upgrade of a classic design.
Inspired by the original Radius concept, which offered an easy, décor-friendly way to live with high quality multi-channel sound by virtue of a wide choice of compact speakers and finishes, these slender new Radius HD models have a refreshingly stylish but unobtrusive profile, which will blend beautifully with any interior, however sophisticated. Available in Walnut and Rosemah real-wood finishes and Black, White and Silver piano lacquer the sleek new Radius HD cabinets benefit from flush mounted grilles to present a clean, elegantly contoured look.
Utilising a further refinement of MA’s Metal Matrix Polymer (MMP®II) and Ceramic-Coated Aluminium Magnesium (C-CAM®) cone technologies developed for Monitor Audio’s award-winning high-end Platinum speakers, Radius HD offers a greater dynamic performance and a wider bandwidth than the original Radius designs.
The nine-strong HD range builds on the high performance and aesthetic standards of the original Radius designs but broadly mirrors their dimensions. As before, with versatile easy-to-fit bracket systems, the Radius HD satellites are designed to operate perfectly in LCR positions. One exception is the ‘R one HD’, a wholly new Radius design, which provides complete system surround sound for use with LCD/Plasma screens. Two new active subwoofers (8” and 10” drivers) complete the line-up.
The new Monitor Audio Radius HD loudspeakers
Approximate retail prices (inc VAT) each:
R45HD £180 (pair)
R90HD £300 (pair)
R180HD £175
R225HD £225
R250HD £250
R270HD £600 (pair)
R one HD £450
R360HD £400
R370HD £500
RHD Stand £150 (pair)
Availability: September 2008

The diminutive R45HD is a surround speaker with a size-defying performance. Its secret is a combination of a 3” MMP®II cone mid-bass driver and rear-firing 3/4” C-CAM® gold dome tweeter, which spreads and magnifies the sound around the room to create a huge, encompassing surround
sound effect. Designed to dovetail with the R360HD subwoofer and available in the Radius HD range of real wood veneers and lacquers, the R45HD will blend perfectly with your décor in an ultra-discreet multi-channel audio or video system. Installing the R45HD on the ceiling or wall is easy by using the
same high quality angled bracket supplied. Use the optional bespoke RHD stand for floor positions.
The R90HD is a high-class mini monitor, only smaller. Unprecedented enclosure
rigidity and leading edge drive unit technology in the shape of a 4” MMP®II mid/bass driver and 1” C-CAM® gold dome tweeter combine to produce clarity, dynamics and imaging abilities that are unparalleled in a speaker of this size. It can fill a room with high fidelity sound and yet visually melt into the background. The R90 can be installed easily on ceiling or wall using the same
high quality angled bracket supplied. Use the optional bespoke RHD stand for floor positions.
If you can trade a little space for more bass, the slightly larger and more versatile R180HD offers the same irresistible blend of virtues as the R90HD, but can be installed vertically as a main, side or rear speaker, or horizontally as a centre channel speaker using the bespoke low-profile wall bracket supplied. Its enhanced bass performance makes it ideal for discreet
music applications around the home. Combined with a R360HD or R370HD subwoofer however, the R180HD will form part of a formidably powerful stereo or multi-channel home cinema system.
The slender R225HD’s contoured profile is designed to match the aesthetic of flat plasma and LCD displays. When used as a centre channel or main speaker, it s acoustic design of twin 4” MMP®II mid/bass drivers and 1” C-CAM® gold dome tweeter provides the signature accuracy of Monitor Audio’s reference speakers. Its impressive size-defying bass performance can be further extended with the addition of a Radius HD active subwoofer. Use it with the R360HD or R370HD subwoofer to create a compact, perfectly matched yet sonically exhilarating audio/video speaker system.
Supplied with a low-profile bracket for horizontal or vertical flush-mounting on the wall, the R225-HD can be customised to complement its environment for the perfect balance of style and performance.
The elegant R250HD has been designed to be sited vertically or horizontally with larger 42, 50 and 60-inch LCD and plasma displays. Providing bass right down to 50 Hz, it can be used as a centre, main, side or rear speaker in a multi-channel music or movie system. At just 105mm deep and in a choice
of luxury black, white or silver lacquers, its suitability for flat screen applications or where space is at a premium is beyond dispute. The R250HD employs the 225’s driver configuration in a longer cabinet, providing the enhanced bass performance that makes it a desirable space-efficient hi-fi satellite for any room.
The R270HD is a super-slim floor-standing loudspeaker designed for genuine full-range performance in a serious music system or multi-channel audio/video system. Excellent fidelity from twin 4” MMPII mid/bass drivers and a 1” C-CAM® gold dome tweeter, coupled with a svelte profile provides the opportunity to enjoy great sound and discreet design all in one package. A choice of luxury real-wood or lacquer finishes supplies a lustrous appeal, giving the R270HD a tactile sense of quality that feelsat home anywhere.
R one HD
The R one HD is a design completely new to Radius. Inspired by the popularity of single box surround sound solutions, R one HD gives the format the Monitor Audio Radius treatment. Enhanced by the luxury curves and finishes, proportions and performance of Radius HD, R one HD integrates left, centre and right channels in one cabinet. Each channel has a dedicated braced compartment and individually specified crossovers. The centre channel section houses twin 4” MMP®II mid/bass drivers and a 1” C-CAM® gold dome tweeter. The left and right channel sections house single 4” MMPII drivers and1” C-CAM® gold dome tweeters.
This super-compact active subwoofer has the speed, subtlety and pitch accuracy to enhance the highest quality music reproduction but it can also deliver the power and slam demanded by movie soundtracks by virtue of its downward-firing 8-inch driver, controlled by a powerful built-in 100 watt Class A-B amplifier. It has a variable crossover frequency control from 40Hz-180Hz, 0-180 phase switch, stereo and LFE RCA inputs, silicone rubber nti-resonance feet and two EQ settings for music or video programme optimisation.
The R370HD active subwoofer provides a new dimension to a system’s sound. Its 10-inch C-CAM® down-firing driver, powered by a potent 250W (RMS) Class D amplifier, will extend the reach of the Radius HD satellites to add the deepest drama to movies and music. The R370HD’s lowest frequencies are controlled so expertly that even subtle effects are better defined, enhancing the listening experience with bass you can feel as well as hear. The R370HD is equipped with atop-mounted control panel for easy access to volume and EQ settings, 12V trigger input for power on/standby control from an AV amplifier, variable crossover control from 40Hz-120Hz, stereo and LFE RCA inputs and link outputs, and two EQ settings for video and music.Technical features
Drivers MA’s engineers have managed to surpass the performance of the renowned C-CAM® tweeter by providing extension in excess of 35 KHz. This ensures that the wide frequency bandwidth of HD music and cinema formats can be replayed faithfully. The tweeter’s new dome profile and surround
geometry have been developed using advanced modelling tools, to provide the optimum qualities for accurate sound reproduction. The gold dome itself is formed from of our trademark C-CAM® material being only 30uM (0.03mm/ 0.0012”) thick, and weighing a fraction of a gram. This lightweight material
possesses ultimate strength when formed into the dome shape and treated with the ceramic coating process. This gold C-CAM® dome is extremely light, strong and possesses the ideal characteristic properties to enable the tweeter to work right up to 35 kHz before any sign of ‘break-up’ occurs. The
Radius HD bass drivers have been completely re-worked and re-modelled with the aid of new design and simulation tools, to achieve higher sensitivity, increased magnetic linearity. A newly shaped T-section pole and focussed magnetic gap have produced better linearity and lower distortion,
resulting fast, punchy bass. All drivers are dedicated and model specific, with each model in the Radius HD series being designed and voice individually.
Crossovers New PCB layouts have been designed to keep signal paths as short as possible. Thicker copper tracks have been employed to reduce losses. Component layout has been optimised to make sure that no interaction can take place between the components themselves, providing a clearer sound
and better signal separation.Where possible, air core inductors have been used for low signal distortion and a faster response to transients.
Internal cabinet damping Box resonance and time smearing effects have been reduced by improved cabinet damping. Our research led us to a combination of polyurethane foam and a polyester fibre material, which provided excellent damping of rear waves, and a cleaner, more open sound.
ARC Baffles (For models R225HD, R250HD, R one HD)
Anti-Resonance Composite (ARC®) was originally developed for the baffles of Monitor Audio’s high-end Platinum series. It is a cast thermo-set polymer loaded with minerals to provide very inert, optimally damped materials. ARC® reduces the stiffness of the driver mounting area, preventing
unwanted vibrations from being transferred to the cabinet.


Active Member
Sounds about right, I just moved over to a R250 L/C/R and R90 rears last month as I needed to save some space :(


Standard Member
orum member illumina finally finished his 235:1 theater.
Just in time for the holidays!!
I love how the screen fills the width of the room with the help of a Panamorph doing its magic.

Equipment details:
Pioneer Elite receiver, dvd player
Celestion speakers
Infocus SP4805
Panamorph U380
Velodyne VA-9100x Sub
DIY 106"x45" BOC screen (total cost: 60 bucks)
mathew hadley
Internet Marketing

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