Review: Monitor Audio Radius 270 Tower Speaker

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Does Skinny = Weak?

Brent Butterworth

Is it possible to please serious music lovers and less-devout listeners? Yeah, but it's rare. Sure, George Benson sounds as great singing "Give Me the Night" as he does playing "Willow Weep for Me." But efforts by pop artists like Rod Stewart and Barry Manilow to tackle the standards haven't been embraced by most lovers of the Great American Songbook.

Monitor Audio's in the same position with its recent revamp of its Radius line. Monitor's earned a rep among audiophiles for well-engineered, great-sounding speakers, but the Radius line is a lifestylish creation built for designer living rooms and small media rooms.

To up the sound quality of the Radius speakers, Monitor borrowed technologies developed for its higher-end lines. These include the company's C-CAM (ceramic-coated aluminum/magnesium) diaphragm material in the woofers and tweeter. The ceramic coating helps damps the resonances in the metal, making the drivers work more like stiff pistons rather than flexible drum heads. As in the company's most expensive tower speakers, the drivers are bolted through from the rear to help stiffen the enclosure (see the back photo on the last page of this review). The ports are rifled, like a gun barrel, to smooth air turbulence.

The $1,249/pair Radius 270 tower speaker stands at the top of the revised Radius line. Given the Radius 270's rated 50 Hz bass extension, you can use it on its own in a stereo system as long as you're not looking for deep or loud bass response. If you want to add more bass or flesh out the 270s into a full home theater sound system, Monitor Audio offers an array of Radius speakers and subwoofers that should do the trick.

It's hard to deny the Radius 270's visual appeal, but you've got to wonder how robust the sound can be when you've got an enclosure less than 5 inches wide, packed with just two 4-inch woofers. Let's give a listen ...

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Monitor Audio Radius 270: Features and Setup

Brent Butterworth

• Two 4-inch C-CAM woofers
• 1-inch C-CAM tweeter
• Five-way metal speaker cable binding posts
• Available in gloss black, gloss white or walnut finish
• Dimensions 39.4 x 7 x 8.2 in / 1,000 x 177 x 208 mm (hwd)
• Weight 21.8 lbs./9.9 kg

The 270 is a simple, elegant little speaker that comes out of the box fully assembled. There's not much to the setup. I put them in the same approximate place I put most conventional speakers; in this case the backs of the towers sat 28 inches from the wall behind them, and I toed both in to face straight at my listening chair.

I connected both to my Denon A/V receiver. Sometimes I ran them full-range, and sometimes I use them with an SVS SB-2000 subwoofer, crossing over the Radius 270 to the subwoofer at 80 Hz.

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Monitor Audio Radius 270: Performance

Brent Butterworth

As I often do when I start reviewing a speaker, I just messed around with the Radius 270, playing a bunch jazz records my friend Nick loaned me. He hadn't listened to them for at least a decade, but they turned out to be pristinely preserved -- not one of them had the slightest scratch. Yet another great reason to own a turntable: You can bum records off your friends who don't have turntables.

My ears perked up right away when I heard the super-spacious, ambient soundstage the Radius 270 threw out on guitarist Gabor Szabo's The Sorcerer, a 1967 side recorded live at the Jazz Workshop in Boston. Szabo's twangy guitar (a steel-string, flat-top acoustic with a single-coil pickup) and drummer Marty Morrell's snare and cymbals sounded like they were echoing off the hard walls of a medium-sized club. I loved the way the Radius 270 seemed to recreate the acoustics of the venue so precisely. As a web search later told me, the Jazz Workshop was indeed a decent-sized basement space, something like the Village Vanguard or Small's in New York City, so apparently the Radius 270 got it right.

Drummer Chico Hamilton's Man From Two Worlds (also featuring Szabo) was even better, with saxist/flautist Charles Lloyd's ethereal sounds seeming to emanate from a big virtual space in the front of my room rather that from the Radius 270s.

Old jazz records, though, are not the most demanding material, so I switched over to my 10 favorite stereo test tracks. Steely Dan's "Aja" (actually not one of my top 10 these days but definitely in my top 15) sounded very smooth, with the hard-to-reproduce piano in the recording showing no trace of the unpleasant hardness most speakers give it. The 270s treated Donald Fagen's reedy voice just as carefully.

I did notice that while Chuck Rainey's bass line sounded tight, it didn't sound powerful, and the piano lacked some body. I also noticed the cymbals seemed to show a little trace of emphasis in the mid-treble, but not as much detail in the upper treble, above 10 kHz. This made me wonder if maybe Monitor Audio's engineers rolled off the treble slightly to better balance the little woofers' lightweight bass output. That'd be a smart move, I think -- sometimes a tweeter with flat response to 20 kHz can sound too bright when paired with small woofers.

My favorite "normal music" track, Toto's "Rosanna," sounded positively huge through the Radius 270, with the colossal, reverberant sound I imagine the group was going for. ('Cause you know everybody back in the early 1980s was going for that sound.) As I pushed the volume up past 92 dBC, measured from my listening seat 11 feet away, the sound got thin and the kick drum lost its kick. On Mötley Crüe's “Kickstart My Heart," the Radius 270 just blared at me when I tried cranking it to a satisfying level. But adding the SB-2000 subwoofer into the system fixed this problem instantly and completely.

I liked what the Radius 270 did with vocals in general; every singer I played through it sounded smooth, with no notable sibilance or midrange coloration. I did note, though, that on James Taylor's recording of "Shower the People" from Live at the Beacon Theatre, Taylor's voice sounded a little bloated in the deepest notes. So did Reverend Dennis Kamakahi on his recording of "Ulili'E." I guessed this was an artifact of a little bass bump I figured Monitor's engineers added to give the 270's tonal balance a more heft. Switching the subwoofer back in, and thus filtering frequencies below 80 Hz out of the 270, brought the lower vocal ranges back closer to the realm of reality.

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Monitor Audio Radius 270: Measurements

Brent Butterworth

Frequency response
On-axis: ±2.8 dB from 51 Hz to 20 kHz, ±2.0 dB to 10 kHz
Average: ±3.5 dB from 51 Hz to 20 kHz, ±2.1 dB to 10 kHz

Minimum 4.7 ohms/280 Hz/+2°, nominal 9 ohms

Sensitivity (2.83 volts/1 meter, anechoic)
84.8 dB

I measured the frequency response of the Radius 270 using quasi-anechoic technique, with the speaker atop a 28-inch (67 cm) stand and the measurement microphone at 1 meter, using the gating function on my Clio 10 FW audio analyzer to eliminate the acoustical effects of surrounding objects. Bass response was measured using ground plane technique, with the microphone on the ground 1 meter in front of the speaker, then splicing the result to the quasi-anechoic curves at 250 Hz. The blue trace in the chart above shows the frequency response on-axis; the green trace shows the average of responses at 0, ±15 and ±30 degrees horizontally. Results were smoothed to 1/12th octave.

These are excellent results. Any speaker that measures with no more than a ±3 dB variation on-axis is generally considered to be pretty well-engineered, and the Radius 270 meets that standard easily. Anomalies? Sure, there's a slight but broad peak centered at 7.5 kHz (probably the cause of that cymbal emphasis I noted), and a mild downward tilt in the tonal balance, which may make the Radius 270 sound just a bit soft. Off-axis response is super-clean, with just a smooth reduction in treble response even way out at 60 degrees off-axis.

Sensitivity of this speaker should be about 88 dB in-room (I measure anechoic sensitivity for the sake of consistency), which is enough that even a 16-watt amp will give you about 100 dB output.

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Monitor Audio Radius 270: Final Take

Brent Butterworth

The Radius 270's not your best buy in a ~$1,000/pair tower speaker, but it wasn't intended to be. You can easily find a bigger tower speaker, like the PSB Image T5, that has a similar level of sonic refinement with a lot more bass output. That's not the point, though. The PSB Image T5 -- and almost all other tower speakers in this price range -- looks like an ugly, conventional box speaker, sure to be loved by audiophiles but hated by those they share the house with.

The advantage of the Radius 270 is that it gives you the refinement of those speakers in a form factor that's vastly more appealing and much less likely to garner complaints from your significant other. For playing jazz or folk or light classical, it's probably all you need. Add a good little subwoofer and the Radius 270 should equal the output of its bigger, bulkier competitors.