They might be smallest members of the ADAM range, but the sound quality remains undiminished.
Text: Brad Watts
There are several ways to build a tweeter: piezos, horns, standard cones and electrostatics all compete in the marketplace, but electrodynamic dome tweeters are the typical choice of most studio monitor manufacturers.
Consequently, one could loosely place the majority of nearfield monitors into a couple of classes: those that use ‘soft dome’ high-frequency drivers, and those that use top-end drivers manufactured from metal. Both these designs have their advantages but neither one is perfect. It’s generally agreed that metal dome tweeters provide a more detailed top end, while soft dome tweeters tend to provide a smoother high-end reproduction.
Fans of metal domed designs tend to be drawn to the ‘crispness’ of their aluminium or titanium tweeters, and are often critical of silk-domes for what they see as a lack of detail. Those in the soft dome camp, meanwhile, repeatedly point to the ‘non-fatiguing’ nature of their preference, and often dislike the ‘harshness’ of the metal alternative. Inevitably it’s a case of horses for courses, and everybody has their preference, but it’s fair to say that both methods can deliver outstanding results. And as with most things in this world, you get what you pay for – an expensive silk dome design will generally trounce a cheap metal dome and vice-versa.
There is, however, a less prevalent tweeter design that’s markedly different from electrodynamic dome transducers. Originally concocted in 1972 by a Dr Oskar Heil, the ‘Air Motion Transformer’ uses a folded aluminium ribbon suspended within a magnetic field. As the ribbon is electronically stimulated, it vibrates, thus moving air. It’s kind of like a ribbon microphone in reverse. Compared with electrodynamic devices that move a piston within a sleeve at a ratio of 1:1, the process of a folded ribbon is extremely efficient, moving air at a ratio of 4:1. But ribbon tweeters weren’t always this efficient. Early designs would merely push air, resulting in quite high distortion figures, whereas modern ribbon tweeters now both push and pull. This fact, combined with high strength neodymium magnets and modern materials for the actual ribbon, has resulted in an unprecedented level of efficiency.
Which, of course, is where ADAM monitors slide neatly into view. ADAM has been at the forefront of ribbon tweeter design for many years now, although the company’s early experiences were mainly restricted to the audiophile arena. Should you care to go wandering through its domestic loudspeaker range you’ll come across domestic models costing 35, 53, and 385 thousand dollars (yes, that’s Australian dollars, and no, none of these figures are a typo).
IT’S ART, BUT NOT AS WE KNOW IT
ADAM denotes its tweeter technology as A.R.T. or ‘Accelerated Ribbon Technology’. The company uses a modern composite for the actual ribbon material – what this material is precisely comprised of remains a bit of a mystery, as I’ve yet to extract any further information from the company, but it’s performance is superior to aluminium nonetheless.
While there’d be very few of us who could afford anything from ADAM’s audiophile range, or for that matter, many of its upper echelon studio monitors, ADAM now produces nearfield monitors for the shallowest of pockets. Enter the ADAM A5, the smallest nearfield released by the company to date, and the most inexpensive way to wrap your ears around the pleasures of ribbon tweeters.
The ADAM A5 utilise a 5.5-inch low-frequency driver alongside the same A.R.T. high-frequency driver as used in allADAM speakers. The low-end driver of the A5 is actually a composite of carbon fibre and ‘Rohacell’ (a rigid closed-cell foam). The A5 is a tiny unit, measuring a Smurf-like 285 x 172 x 200mm and each one is magnetically shielded (should you still be forced to work amongst CRT displays). The A5 is self powered via two 25W amplifiers – one amp for each driver – and provides an SPL of around 110dB at one metre, which is an incredible achievement for such a tiny cabinet. The bass reflex design can reproduce frequencies down to 55Hz, with two ports escaping from the front of the cabinet. Between the two ports you’ll find a power switch, a volume control, and two LEDs. One of these is blue and indicates the monitors ‘power on’ status, while the second LED is white and indicates the unit is in ‘link’ mode.
What is link mode? Well, I’m glad you asked.
The rear of each individual A5 features two RCA connectors in addition to the one that accepts either left or right RCA audio inputs. These are labelled ‘Stereo Link’: one for ‘input’, the other for ‘output’. If you don’t have a volume control system, this linking setup allows you to connect the signal source of the second ADAM A5 to the ‘master’ speaker, which then connects the ‘slave’ via its output RCA connector. Now the volume of both monitors can be attenuated from the one control – very handy indeed. While the speakers are in this state the white LED (on the ‘master’ monitor – whether it be left or right) will light up. This is a cool feature for those without a dedicated volume control, but do be warned, the pots on the ADAM A5s don’t offer the most stable of left/right balances at lower volumes using this method. A better option would be to grab a $60 attenuator like the little SM Pro Nano Patch reviewed in Issue 64 for superior results.
While we’re still looking at the rear connectors, I must say I was a tad bamboozled by the choice of RCA connectors rather than something more serious, like a 1/4-inch jack, but then I’d imagine there’d be a number of people using semi-pro audio cards with the ADAM A5s, and many of these devices offer RCA connectors as their only output option. For the best results, however, you should definitely use the balanced XLR inputs also available on the rear panel. The only limitation with this alternative is that the aforementioned single volume control system won’t work – it only functions when the RCA inputs are being utilised.
Below the connector section are three recessed pots. The first of these is for adjustment of the overall tweeter output (up to ±4dB). The other two pots provide shelving EQ control above 6kHz and below 150Hz. The pots are stepped so you can match each monitor – just be sure you know what you’re doing here and cross-check your mixes before adjusting these controls willy nilly. Below these – alongside the IEC mains input – are two threaded recesses for attaching the monitors to mounting brackets.
ART OF NOISE
Apart from all this, the big issue is obviously how the little ADAMs sound. Being one who’s firmly ensconced in the silk soft dome tweeter camp myself, I was very interested to hear the ADAM A5s perform. I’d listened to their larger brothers in other studios but hadn’t ever really had the opportunity of spending any substantial length of time listening to familiar music through them.
I’ve got to say, these things are very impressive. Ribbon tweeters seem to offer the best of both worlds: detail and clarity without the stridency of metal dome drivers. Just to convince myself I wasn’t simply enamoured of a new set of monitors, I set up two alternate pairs that used metal dome tweeters along with my usual Questeds and Spatial Ones – both of which use soft dome technology (although the Spatial Ones are somewhat unique in other ways).
The two monitor systems wielding metal included an old set of JBL monitors that I’ve owned for years (and absolutely detest), and a set of PMC monitors that reside in the AudioTechnology studio. Chalk and cheese was the first cliché that immediately sprang to mind – the ribbon technology of the ADAMs, on first listen, sounded brilliant. Clear-as-a-bell top end without cymbals meshing with each other or firing daggers at the listener. You can hear the ripple of hi-hats closing as the drummer brings his or her foot down on the pedal, rather than one continuous high-frequency ‘schlloop’. String sections, meanwhile, gain a surprisingly natural sweetness not encountered with either the JBL or PMC monitors, and all of this without the ‘fatigue’ one experiences within a few minutes of listening to the metal dome designs. Admittedly, metal dome technology has come a long way since the release of the five-year old PMCs – and certainly the JBLs – but there’s something that just unnerves me when listening to metal tweeters. Yes, I have listened to some of Genelec’s recent offerings like the 8050As (I can’t deal with 1032As) and I still start to squirm when I hear that top-end battering away at my tympanic membrane. Suffice it to say, the ADAM A5s don’t do that. Their sound is precise, yet smooth and reassuring – perfect for those times when you’re faced with 80dB sound pressure levels for hours on end.
As far as bottom end is concerned, remember these are small speakers, so you certainly won’t be shaking the floorboards with them. The tiny cabinet and 5.5-inch low end driver will give you some ‘welly’ down to 55Hz, but below that you’ll need a sub cabinet – which is where that bottom-end EQ control will also come in handy.
As they stand, the ADAM A5s have really opened my ears as to how well high frequencies can be reproduced by a ribbon tweeter. If you’re in the market for a tiny nearfield you must put these monitors on your audition list.