Call in the professionals

Acclaimed by studio engineers, does Genelec’s triple-coaxial ‘The Ones’ design transfer its strengths to the home?


How easy is it to incorporate ‘professional’ audio equipment in a more consumer hi-fi context? In some areas, pretty easy. Take headphones — not so very long ago, consumer headphones were priced below professional headphones, for the apparently obvious reason that pro gear was going to operate to higher standards than consumer gear. But then consumer headphone prices rose higher and higher, and today your staple studio headphones — a Sennheiser HD280 Pro or beyerdynamic DT770, say — are looking more and more the bargain (though specifications can vary — some pro headphones are not designed for portable use, for example).

What about speakers, and in particular active speakers? Active speakers are the new darlings of home hi-fi, being exceedingly décor friendly, no amplifiers required, and potentially no sources either, except your phone. Yet active speakers are long established in the pro market, and some have garnered a reputation with audiophiles as well as engineers, Genelec being a prime example.

“We aim to deliver performance-driven tonally neutral Studio Monitors”, says its website, which has as much information about musicians as about equipment. Performance-driven tonally neutral Studio Monitors, did they say? Well that sounds pretty good. But will they work in a domestic environment? Let’s see.

Genelec does have a series of domestic models for the home, and architectural (in-wall/ceiling) speakers too. But the fame of this 40-year-old Finnish company is built on its studio monitors, which range from the compact and relatively conventional to models which Genelec calls ‘SAM’ monitors (for Smart Active Monitors), which can be controlled by the company’s Genelec Loudspeaker Manager (GLM) software and can benefit from autocalibration with a microphone to optimise them to your room environment.

Among Genelec’s SAM speakers are coaxial designs, including the acclaimed series known as ‘The Ones’, from which comes the model under review here, the 8351 SAM Studio Monitor.
Coaxiality — where one driver sits within another, or is perfectly aligned with it — has a long history in studio monitoring (back to a 1943 Altec Lansing design and a 1947 Tannoy, indeed). The benefits are time alignment, a true ‘point source’ of sound, renowned for delivering accurate soundstaging in particular, and also less variation in tone when moving off-axis. They also allow you to sit closer without breaking a designed alignment of separated drivers; Genelec says you can sit within 40cm of these 8351s without such issues — which might well be handy for a studio-type position with monitors by the desk.

We know the benefits of coaxiality from consumer hi-fi, of course, famously KEF’s UniQ drivers which nestle the tweeter within the midrange. But three-way coaxiality, with the woofer also aligned with midrange and tweeter, is much more unusual in home hi-fi, though sometimes used in car audio. KEF’s home solution for three-way coaxiality was to use multiple bass drivers to create a ‘virtual’ source positioned coaxially behind the UniQ midrange and treble in its Blade and Blade 2 creations. Cabasse’s La Sphere comes to mind as a genuine four-way coaxial, but being enormous and upwards of quarter of million dollars, it is not for everyone.

Genelec has achieved three-way coaxiality using what it calls an Acoustically Concealed Woofer (ACW) — curious naming given it’s actually visually concealed but acoustically very much present, happily. In the 8351 model the concealed ‘driver’ actually comprises two oval woofers behind the integral front baffle, and these radiate through slots located top and bottom of the front fascia. These openings are optimised in size and curvature to minimise acoustic diffractions from the die-cast aluminium cabinet, which is itself further curved and rounded to achieve minimal diffractions. Genelec claims the pair of woofers, each 215 × 100mm, behave acoustically like one larger woofer spanning the distance behind the front baffle, and thereby achieve true point-source performance.

Meanwhile that front baffle, which remarkably forms a continuous part of the enclosure’s front half, allows mounting of the coaxial midrange/tweeter assembly, which Genelec calls an MDC ‘Minimum Diffraction Coaxial’ driver. This is unusual enough in itself that our brethren at Australian Hi-Fi were soon gathering around to poke the roll-less 5.75-inch midrange diaphragm, which has no conventional spider and a suspension that is made of foam over the entire cone. Within this sits the dome tweeter protected by a light mesh grille. The moulding of the front baffle creates a waveguide for the pair.

Three finishes are available — white, black, and the attractive speckly-sparkly granite grey of our review pair, as pictured.

The crossovers in this three-way system are set at 490Hz and 2.6kHz.

And these are active speakers, as noted. They contain Class D amplifiers for the bass and midrange drivers rated at 150W and 120W respectively, with 90W of (interestingly) Class-AB power for the tweeter. So if you’re thinking the price is relatively high, despite all the clever technology, remember that you won’t be needing to budget for power amps.

On the other hand, as we realised when we came to connect them, you will most definitely require some kind of preamp control, along with a potential rethink of how your entire system fits together.

Calibration & correction
The software which allows both room correction and control of ‘The Ones’ is free from Genelec’s website. We downloaded the GSM 3 version for Mac, which on first installation declared OS High Sierra too advanced for the software, on second launch dived into a software freeze, but on third attempt launched and worked successfully.

You need hardware too, and as mentioned in the main panel, it comes at additional cost. This network adaptor kit includes a small hardware box into which plugs a USB cable for your computer, the microphone which comes as part of the kit, and an Ethernet cable off to one speaker, from which a second Ethernet cable connects to the other speaker. In fact the software is capable of tuning and controlling far more than a simple stereo set-up (up to 45 speakers and/or subwoofers), and your first task in software is to select a speaker and drag it to its approximate position in the room diagram. The speakers quietly hiss when selected, so you can easily identify which is left and which right.

With the layout of your group confirmed, you can get on with calibration, which involves getting the microphone in the position between your ears, and setting off the joyful whoops of autocalibration — just a single whoop per channel here. You can force the EQ to be the same for both speakers, which may have benefits in maintaining the very best soundstaging between the speakers, but if you have a lopsided room in any way, release this option to get the best possible compensation.

You can see the software matching the curves to flatten the speaker response, then with your calibration confirmed you can load those settings into the speakers themselves.

At that point you can unplug the calibration kit; the settings will remain in the speakers, though you can select or deselect the saved setting using one of the rear DIP switches. Should you move the speakers at any time, you’d need to do it again. We’re told that a studio with a few rooms of Genelecs would probably buy a kit to keep on hand, whereas a humble home user might not.

But if you do, and keep it connected, the GLM software can also be used to control the volume level of the speakers, rearrange them quickly into different configurations, apply different calibration choices for different occasions, and a whole lot more.

In a studio with a central console including computer, you can see the value of keeping it all connected. In a home environment, computer control may be rather less convenient, and standalone operation will likely better suit domestic users.

The 8351 speakers are the size of a large standmount speaker, around 45cm high, making the 8351 an exceedingly compact three-way speaker indeed.

They are curved on the base, so they don’t sit easily direct on stands, but are rather designed to sit on their clever ‘Iso-Pod’ bases of hard but lossy rubber (see above). These provide four small feet ideal for table positioning or wide speaker stands, with the additional merit of sliding back and forward to allow the speakers to be tilted (up or down) by up to 15 degrees — crucially useful given that ideally you want those coaxial sources aimed right at your ears. Genelec’s description of the base as an “Isolation Positioner/Decoupler” highlights that the rubber will also minimise the effect of vibrations from below, while reducing first-order surface reflections. You can also switch the Iso-Pods to the sides and have the speaker horizontal, which — as a coaxial speaker — matters not at all.

The 8351 enclosures port to the rear and Genelec’s instructions are very clear — no more than 30cm from a rear wall to avoid reflections (from the baffle, rather than the port) reducing their bass output, and absolutely avoid distances of 1-2.2m from the wall. Having said that, deep in the back panel are a host of tiny DIP switches, 14 in all, which can be configured to deliver adjustments for positioning — treble and bass tilts (‘tilts’ are shelf EQs which raise one part of the spectrum while reducing another) and a bass roll-off. But for neutrality within your room as well as from the speakers, you can use Genelec’s GLM software and kit, including microphone, to calibrate the speakers for your room. The downside is that this isn’t included, and the kit costs $610. But your Genelec dealer may help you out there. (See panel, previous page, for more.)

Now here’s the fun bit. Being professionally inclined, the 8351s favour balanced connections on XLR sockets, with none of your hi-fi RCA unbalanced line-ins. Each speaker has two input options — a single XLR analogue balanced input, or a single digital AES-EBU input (also an XLR-style socket). Since the digital connection is stereo, this also has a ‘through’ socket to the other speaker. With analogue, you just connect left to the left speaker, right to the right.

There is no local volume control (unless you have the GLM software permanently connected — see above). That means you will need some kind of preamplifier with balanced outputs and volume control, with your two XLR analogue cables running to the active Genelecs. Compare this with what you’re currently using at home, and you’re likely to find that going for a pro solution like this may require a complete rethinking of your system.

On the other hand, if you’re a home DJ or musician with everything plugged into a little mixer with balanced outputs, you’re pretty much ready to play. And post-calibration (see above), the Genelecs were on song immediately, and revealed the plus sides of going pro.

There is no bloat here, no friendly bass lift to warm up your ears. But nor do they slip the other way into sounding analytical. Neutrality is the word, as it should be for a studio monitor — and here it is neutrality with soul.

The Last Day on Earth by Kate Miller-Heidke is a good straightforward studio production, and hearing it through the 8351s you can just imagining them signing it off at the desk, the deep soft kick of the bass drum, her delicately double-tracked harmony given a little cut-through EQ, wide-panned twin pianos — these speakers proved to be a window into the art of production, as well as a wonderful presentation of the music.

For rather more studio artifice we turned to The Last Shadow Puppets’ 2016 album, fusing 1960s’-style strings over bouncy baroque pop. Even the most complex sections were cleanly separated, the powerful whole punched out but with each element of it distinct in the mix. Tonally we found them untouchable as well, delightfully highlighting the clicky bass guitar while the kick drum behind gave it solidity and weight.

The Genelecs simply shined with unlimited acoustic material, whether modern Beth Orton or the high-res unlimited remaster of McCartney’s Every Night from 1970, recorded at home straight to Studer, the snare whipcracking in the right channel, Macca’s vocal pure and unprocessed in the centre, always at the front. Again the staging of acoustic guitars across the soundstage was a delight from the Genelec coaxial drivers.

Such classics proved irresistible — a song as jaded as Carole King’s So Far Away emerges clean and tangible, so very open that you can hear how the piano was miked to add a little distance, the voice smooth and high but not peaky, the acoustic guitar in the left channel astoundingly sharp-edged, while the kick drums in the right channel had all the depth of a modern recording. This is the time travel great hi-fi can deliver, bringing the past into your present.

We turned to Mozart’s brief (eight-minute) but charmingly joyful Symphony No. 22 (Philips, 16/44, Neville Marriner Academy of St Martin-in-the-Fields). Here we could relish the soundstaging from the Genelec coaxiality, presenting the orchestra with not only pinpoint left-right positioning but a deep front-back differentiation.

We played Keith Jarrett’s Köln concert and the 8351s perfectly delivered the slightly thin tone of his ‘wrong’ Bösendorfer piano, and on the third section where Jarrett starts banging keys with remarkable force you could distinguish precisely how hard each finger was impacting each invory, and also hear deep details in the bass of his foot banging the platform, plus his accompanying moans leaning right, favouring the piano’s treble microphone.

Accuracy, dynamics, plenty of level (they seemed unbreakable) — was there anything the Genelecs couldn’t do? We sometimes thought kickdrums and deep stuff a little soft — a characteristic of a concealed woofer? On something as tricky as Blue Man Group’s Opening Mandelbrot the toms were clean enough but the underlying kicks were more thunderous in support than beat-for-beat delineated.

On Genelec’s website there is a series of cosmic videos called ‘The Science of Sound’, with swirly music and a voiceover like The Hitchhikers Guide to the Galaxy. It perfectly matches the personality of the company, and the cool technology here — we note also a profession for sustainability and green values in efficient use of material, low energy consumption, and longevity. With the 8351s’ dynamite performance, whether for studio monitoring or hi-fi listening, their hardy construction and versatility of tweaking to a room environment, we imagine anybody with a pair would enjoy that longevity to the last drop. As ‘pro’ monitors they may not plug easily into a domestic system, and there’s that tuning kit to consider if you ever move them. But should The Ones fit your needs, well, they are special Ones indeed. 

Genelec 8351 
Price: $11,000

+ Thrilling imaging and staging
+ Utterly neutral
+ Room compensation possible

- Balanced connections only

Network adaptor kit (for calibration): $610
Quoted frequency response: 38Hz–21kHz -3dB, 32Hz–40kHz -6dB
Drivers: 19mm tweeter + 130mm midrange in coaxial driver, 2 x oval 215 x 100mm woofers
Internal power: 150W + 120W Class D (bass/midrange), 90W Class-AB tweeter
Inputs: 1 x XLR analogue; 1 x XLR AES/EBU digital; 2 x RJ45 control network
Outputs: 1 x XLR AES/EBU digita pass-through
Dimensions (hwd): 452 x 287 x 278mm (with IsoPod base)
Weight: 19kg