Monitor Audio Radius HD R270, A happy balance

MONITOR AUDIO AND BREAK-IN

• An excellent balance between design, modest dimensions, good musical performance and a more than competitive price

• Price: €780

• Specialists' rating: 5

• Text: Luis LLANA

Because of aesthetic or functional constraints in our future listening room, we may well have to give up on that pair of floorstanding speakers we liked so much in the store's demo room, even though they were not excessively large. On the other hand, it would be a mistake, in my opinion, to consider the alternative of the monitors one step below those floorstanders in the range, because with the necessary stands we will have another "eyesore", certainly lighter, but taking up the same living space as the floorstanders, with the added drawback of poorer low-frequency performance. Unless we put into practice the much-repeated false axiom of "bookshelf speakers" and install them on the shelf of a bookcase, in which case musical disaster is guaranteed.

Some manufacturers rack their brains and offer what they call "design" solutions, whose small dimensions, in a more or less successful cabinet concept, are their only reason for existing, because their musical qualities are usually questionable for listening with genuine high-fidelity aspirations. With its experience and mastery of woodworking for loudspeaker manufacture since 1972, Britain's Monitor Audio goes further and offers the Radius HD series, positioned halfway between design speakers and conventional ones, bringing together the best of both worlds with a happy balance of design, discreet size and sonic performance.

It is a loudspeaker range aimed primarily at home theater systems, with models that prove their worth in strict stereo, as is the case with our guest, the R270, the top model in the series. The Radius HD range offers three floorstanding models, two small monitors, one center channel speaker also suitable for the surround channels, two subwoofers, a dedicated speaker for mounting under a flat-screen TV, and various stands for the monitors. The series catalog offers no packages for multichannel audio.

I suspected what I was going to find inside the single carton for a pair of R270s, but, accustomed to the usual proportions of, let's say, conventional speakers, I could not help being surprised by the extreme slimness, almost "anorexic", of my guests, in a glossy silver finish that does not go with my room at all, although its execution borders on perfection. But since there are as many tastes as there are colors and possible decors, Monitor Audio offers other finishes to harmonize with any setting: white and black lacquers, genuine walnut veneer, and also genuine rosemah veneer, as the manufacturer calls it in English, because I don't know what type of wood it refers to with that word.

I have never removed the drivers from any speaker to look at their motor systems and investigate the interior, because this simple operation could damage the airtight seal usually found between the driver and the cabinet and cause subsequent air leaks, impairing the reproduction of low frequencies. But with the R270 it would have been really complicated, because each driver is secured and mechanically decoupled by a single bolt that runs through the whole cabinet from the rear panel, also acting as a tie brace to increase the cabinet's solidity and prevent resonances.

Since the driver grilles are firmly anchored to the cabinet (I broke a nail trying to remove one), access to the interior is probably gained by removing the four screws in the base to start taking things out. Be that as it may, I mention it to illustrate the superb construction of the speaker as a whole, based on a robust, perfectly assembled wooden cabinet (a constant at Monitor Audio), whose rounded vertical edges are the best remedy against the diffraction of sound waves striking those critical areas. These solutions and the narrowness of the front baffle, just 125 mm wide in contrast to its 1,000 mm height, ensure the R270's low coloration and its generous horizontal dispersion angle (low directivity, if you prefer), according to the listening tests.

Electroacoustically, it is a two-way bass reflex design with three drivers and two tuning ports, one on the front hidden by a grille and another at the rear. The two low- and mid-frequency drivers have been completely redesigned with the help of simulation tools to achieve greater sensitivity, low distortion and higher concentration of magnetic flux in their magnets. The 100 mm cones are an MMP II (Metal Matrix Polymer) structure, consisting of a polypropylene base loaded with metal particles and subjected to a high-pressure injection molding process to achieve different thicknesses at critical points in order to optimize rigidity and sonic coherence. According to the manufacturer, there is a specific driver for each model in the Radius HD series.

For the dome of the 25 mm tweeter, Monitor Audio uses one of its leading developments for its higher-end models, an aluminum-magnesium alloy known by the acronym C-CAM (Ceramic Coated Aluminium Magnesium), which provides treble extension up to 35 kHz with excellent linearity. All the drivers used in the Radius HD series are shielded to prevent magnetic leakage, which can also affect the microprocessors in plasma or LCD televisions, not just CRT-based ones.

The crossover is built with polypropylene capacitors, air-core inductors and others with laminated iron cores offering low distortion and insertion losses, and its wiring to the drivers and to the pair of binding posts (which accept any termination) uses high-purity PCOFC copper cable. It includes a self-resetting protection circuit that reactivates a few minutes after being tripped by an overload. Damping and stability are ensured by a high-mass base, but it is best to keep an eye on the sturdy little ones of the house. The manual (in English, of course) states that four decoupling spikes, included as standard, can be fitted after first removing the rubber feet from the base.

To listen to them, I connected the pair of R270s to the two-channel electronics in my system: a Marantz SA11-S1 SA-CD player and an RHA-10 preamplifier and RHB-10 power amplifier, both from Rotel's Michi series, using Integration interconnects and The Wind speaker cables, both from Van den Hul. With the speakers brand new (I had to cut the factory seal on the carton), on first listening I detected a certain hardness in the upper midrange and treble, typical of speakers that need a few hours of break-in (see box), so I will exercise some judgment to set this matter aside. My experience with other Monitor Audio models vouches for, if you will allow the term, the superb behavior of the C-CAM alloy diaphragm fitted to the firm's various tweeters, and its sonic excellence after hours of operation.

It is also true that this might go unnoticed by those not used to listening to speakers, because there are no signs of harshness or aggressiveness in the excellent treble, which is smooth and very clear, judging by the violins of Gidon Kremer and Fabio Biondi, which immediately expose a driver system of questionable quality. As for the soundstage, the R270's low directivity allows very flexible placement, with each speaker angled between 22º and 30º (according to the manual) from the axis of symmetry as seen from the listening position. I verified this by deliberately varying the position and orientation of the R270s from what I considered the ideal placement, and my "soundstage tool", Jacintha's voice on Lush Life, barely suffered with respect to its usual exact location.

They are very clear and detailed with small nuances, and they render voices and string instruments with elegance in the arias and choruses of J. S. Bach's Matthäus Passion (St Matthew Passion), in Philippe Herreweghe's version, whose final chorus the R270s reproduce with the fullness this sublime work requires, with proper separation of the sound planes on a stage that extends beyond the boundaries of the speakers. As for the lower part of the spectrum, their ability to go down in frequency to limits unthinkable for two drivers of just 100 mm is incredible, with truly vital and powerful bass, but best of all is the cleanliness and sense of control of these two small and surprising drivers at those frequencies. I must only point out a certain emphasis I noticed in the mid-bass with some recordings featuring a strong double bass presence, but it is not bothersome and implies no lack of control. Nothing to object to in their excellent impulse response and their ability to generate a respectable sound pressure level of 108 dB, without the slightest fuss or compression, with our usual third movement of Rachmaninov's Piano Concerto No. 3 with Volodos, Levine and the Berlin Philharmonic.

I tried them for home theater, crossed over at 80 Hz on a Tag McLaren AV32R AV preamp-processor, sending the lower frequencies to a Bowers & Wilkins ASW800 subwoofer. After calibrating the front channels, the R270s held their own with the excellent HTM center channel speaker from B&W's 800 Matrix series, despite the qualitative differences and different sonic personalities, and the actors' voices maintained their tonal coherence regardless of their position on the stage. To sum up, the Radius R270s do not reach the exquisite delicacy of their big sisters in other Monitor Audio series, but given their level, nor do they try to. Nevertheless, thanks to their excellent balance between design, modest dimensions and good musical performance, to which I now add their more than competitive price, they stand out as a superb alternative when the constraints of the room lay down their inexorable law.

MONITOR AUDIO AND BREAK-IN

We bring up the subject of break-in again to remind you that every loudspeaker, like any electromechanical component, needs a period of mutual adaptation (break-in, if you prefer) of its moving parts, which may last a few hours or go on considerably longer. This disparity is probably related to the different degrees of elasticity or stiffness (known as compliance) of the driver elements subject to mechanical stress, such as the spider centering the voice coil and the surround of the cone or dome. Monitor Audio estimates it (in the FAQ, Frequently Asked Questions, on its website) at between 50 and 60 hours for the Bronze series and between 70 and 100 hours for the Platinum, with no specific mention of the Radius HD. To speed up the process, it recommends connecting one speaker with the cables reversed (out of phase), placing the two face to face almost touching and playing music at a medium level. As a tip from yours truly, this process can be accelerated with some specific tracks on the Burn-In CD, a CD-DA distributed by the Dutch loudspeaker manufacturer Kharma.



You will understand that when I receive speakers to test for you, and remove the factory seal from the carton myself, I am obliged to include in the article a certain amount of judgment about something as tremendously subjective as listening to a loudspeaker. It happened to me in the test of Monitor Audio's fantastic PL300s, when I had to go back to the store a few days later because of their obvious hardness, and it has happened again with the Radius R270s, with no time to complete their break-in and eliminate certain signs of roughness in the upper part of the spectrum. The tweeters of both models share as their basis the excellent C-CAM (Ceramic Coated Aluminium Magnesium) dome, although the similarities between the two drivers end there.

Monitor Audio Radius HD R270, A happy balance

Specifications

FREQUENCY RESPONSE 48 Hz–35,000 Hz. SENSITIVITY 90 dB. NOMINAL IMPEDANCE 8 ohms. RECOMMENDED AMPLIFIER 20W – 150W. MAXIMUM SPL 108 dB. DIMENSIONS 1000 x 125 x 140 mm. WEIGHT (each) 10.2 kg. DISTRIBUTOR Uno800 (934855062).

Price: €780