It’s ART: According to Adam
Get ready to dump just about everything you know about studio monitors, because now available in Australia is the entire range of Adam Audio. These are German designed and built studio monitors that will turn any studio into the audio equivalent of the Garden of Eden.
There’s a new and very sonically pleasing noise being made in major studios around the world at the moment. This applies to not just the big bangers on the Sonex clad far wall, connoisseurs of near field monitors and project studios are also “hearing where no man has ever heard before” in increasing numbers. And the studio monitor making all these (sound) waves through the industry is Adam.
Why the Adam studio monitors sound so different to anything you’re used to listening to is another story. It’s a very technical story of course and here at Filter, we have the industries smartest readership. Unlike some media outlets, we are not into delivering cheesy dumbed-down sales brochure type gear and technology reviews – we go deeper than that. So get your white “boffin” coat on ‘cause we’re going straight to tech-town with a rave about something completely new in studio monitors.
At first glance an Adam studio monitor has a “funny looking” top-end transducer. We have seen electrostatic and ribbon-looking transducers before, but unless you have previously heard the name Dr Oskar Heil, don’t confuse this with your garden-variety ribbon tweeter. The first thing you notice when you listen to an Adam studio monitor is the natural sounding top end. This makes acoustic instruments and voice sound so realistic, you won’t want to listen to a conventional horn or dome tweeter loaded top end ever again. The mids and bass are both stunning as well but let’s focus on the HF for a moment.
Accelerated Ribbon Technology
Now don’t be put off by the ART acronym, this is a brief history lesson. The top-end transducers are all manufactured in the Adam factory in Berlin and are described under the heading of Accelerated Ribbon Technology. The A.R.T. (Accelerated Ribbon Technology) tweeters and midrange units take a completely new approach in kinematics (the branch of physics that deals with the characteristics of different kinds of pure motion without reference to mass or to the causes of that motion) to move air and improve the quality of music reproduction.
Let’s take one apart
Based on the original works of Dr. Oskar Heil, who invented his "Air Motion Transformer" back in 1972, Adam has refined and developed new electro acoustic transducers that are based on improved layouts and new materials. The membrane consists of a lamella like folded diaphragm whose single folds move according to the alternate current, thus squeezing air in and out. All other loudspeaker drive units, whether they are voice coil driven, electrostatics, piezos or magnetostatics, act like a piston, moving air in a 1:1 ratio. This is undesirable, as the specific weight of air is much lower than that of the driving mechanics. Speaking in terms of electrical engineering one could say there is a bad match between source and load.
The yellow/lime-corrugated film is the diaphragm.
The original Heil design was bi-directional and produced a figure-8 pattern polar plot of exactly mirror image.
An example of load matching can be done on your desk with a simple experiment.
- Put a paperclip on your desk.
- See how far you can flick it across the room with your thumb and finger.
- Now do it again sweeping your whole arm.
The mass of the finger is more closely matched to paper clip and its delivery of force transfers energy much more efficiently to the clip.
The mass of the air is way out of proportion to the mass of a titanium diaphragm that can access only a small portion of the air. That is why we bolt horn flares onto top end drivers, to improve the air mass loading, but this causes other problems. The A.R.T. principle achieves a 4:1 velocity transformation between driving diaphragm and driven air, i.e. the air moves in and out four times faster than the folds its self are moving. This superior "motor" is responsible for the enormous clarity and transient reproduction that is to be heard from the A.R.T. drive units.
The aluminum-clad Heil AMT/AVT driver, which is inherently bidirectional, is held in place by a wooden bracket, located toward the rear so that it is clear of the direct output of the woofer. In place of typical domes or cones, it features a large corrugated diaphragm, described in detail in the following section. Sensitivity is rated at 94dB, and overall frequency response at 28Hz to 23kHz. The crossover frequency is 700Hz, which means the AMT driver is covering an impressively broad frequency spectrum.
Dr Klaus Heinz, the principle owner and designer of the Adam speakers was a close associate of the late Dr Heil and has taken the theory and practice of this very clever physics based approach to a natural finale of mathematical and engineering reasoning. It starts with a clean sheet of paper to analyse how a conventional system behaves.
Problems Of Loudspeaker Design
Spurious Diaphragm Resonances:
We’ve all heard that 3.5k harmonic ring you can’t get out of some horn drivers. Any solid material made to vibrate by striking it or otherwise setting it in motion will produce a pattern of resonances characteristic unique to that particular material. If made to vibrate at a specific frequency by an external driving force it will introduce, in addition to that frequency, its own resonances. That’s why Sitka spruce is so popular for acoustic guitars, bell brass for bells etc.
In music, the pattern of these resonances (harmonics) is peculiar to each instrument and enables us to distinguish, for example, between the sound of a saxophone (metal) and an oboe (wood), even when both instruments are playing the same fundamental note. This characteristic, useful in recognizing musical instruments, constitutes a major problem for the loudspeaker designer, since spurious resonances generated by a diaphragm will distort and mask the musical signal. In order to move a large amount of air, with minimum loss and provide fast transient response, the diaphragm must be extremely lightweight.
However, diaphragm material that is too thin and light will not be sufficiently rigid to prevent it from flexing and producing its own audible resonances. If the deformation occurs between the center area and the edges of the diaphragm, that portion will vibrate independently of the music signal and produce standing waves; bell-shaped vibrations that are clearly audible as distortion. In addition, the diaphragm will store the resonant energy, and when the music signal stops it will continue to move in order to dissipate that stored energy. The continued vibration of the diaphragm will damp (absorb) the sharp rising transients of the ensuing music and seriously affect the accuracy of the music reproduction.
Efforts to Eliminate Unwanted Resonances:
Attempts by designers to minimise diaphragm resonances usually involve coating (damping) the diaphragm with silicon, rubber or other substances to increase rigidity and prevent flexing. There is a trade-off, however: while the damping material may help to reduce resonances, it adds to the mass of the diaphragm, increasing inertia and resulting in slower response to the transients of complex musical waveforms. These damping methods can reduce to a mere 0.25% the ability of many loudspeaker diaphragms to move air efficiently.
The You can see the relative size of an unfolded A.R.T tweeter and a conventional diaphragm. There are many inherent benefits in the folded tweeter that automatically solve the many of the fundamental problems with the conventional dynamic dome diaphragm.
Large Diaphragms and Differentiated Driving Force: Efforts have been made to minimize unwanted diaphragm resonance by applying the driving force more evenly over a large area of the diaphragm. Electrostatic loudspeakers distribute the driving force over a large, flexible plastic panel suspended on a framework. EMIT and magnetostatic loudspeakers utilize a differentiated driving force applied to different areas of the diaphragm to compensate for the varying flexibility of its surface.
However, when a flat or conical diaphragm supported at its edges is caused to vibrate, only part of the diaphragm oscillates in a direction perpendicular to its surface. At the outer edges where it is suspended, the diaphragm cannot oscillate in the same manner, since the surface of one side will stretch with each + oscillation, while the reverse side will be compressed — and vice versa. Thus the entire diaphragm does not move uniformly like a rigid piston, but vibrates like a suspended flexible membrane, producing a self-resonance with a pitch.
A new approach in geometrics and the use of previously un-available materials enabled ADAM to redefine the original idea and build tweeters and midrange units we consider being second to none. The name for the new Technology is A.R.T. (Accelerated Ribbon Technology). A.R.T. tweeters are superior in musical clarity and transient reproduction.
They have an above average efficiency of ~93 dB/W/m, a perfectly linear impedance of 3.2 ± 0.05 Ohms, an equally perfect phase response of ± 1° within the used bandwidth, a reasonable directivity characteristic and a thermal power handling g that exceeds that of 1" domes by a factor of 2 to 3.
Summed up here is a completely new transducer that has no weaknesses in terms of operation, compatibility, reliability or other electroacoustic specifications. Looking back into loudspeaker history you will not find anything comparable. So much for the hi-mid technology, why the great bass response? That’s another story for another Filter. What about seeing some black boxes?
Can you see yourself here?
The range starts with a collection of near field monitors, graduates to a broad group of mid-field, and culminates in some real monsters for those who like their full bandwidth program accompanied by an “authentic dynamic range”. We will just gloss over a few of them but if you check out the web site at the end, you’ll see a considerable collection. The entry near field is the recently released A7. With the optional sub, it is the ideal system for a project or digital studio.
The A7 matches the A.R.T. tweeter with a state of the art 6.5“ woofer that introduces a new cone material combining high rigidity and high internal damping with low weight, resulting in an extremely accurate monitor with all the clarity, detail and spectacular imaging traditionally associated with the ADAM name.
The Adam A7 is powered by two 50W RMS amplifiers (one per driver), and the front panel sports both a power switch and volume control. The rear panel houses controls for tweeter level and two shelving filters for high and low frequencies. The unit also features both balanced (XLR) and unbalanced (RCA) input connectors, allowing it to be used in almost any audio application.
The Sub8 houses an excellent 8“ woofer with a large 50 mm voice coil, and is driven by a 160-W ICE Power amp. This amp stays cool while handling maximum power levels even if they are sustained. The front baffle features two motorised knobs that let you tailor input level and crossover frequency settings for the best performance in your studio. These knobs can be controlled with an included wireless remote, allowing you to optimize your sound reproduction from your ideal listening position.
The Sub8 is an ideal match for ADAM monitors such as the ANF10, P11A, S1A and S2A. In addition to a traditional black model, ADAM will also offer a silver version that will be a perfect complement to the Artist desktop monitor.
The Adam Artist Desktop Monitor
The Artist is a small, unique active monitor that is dedicated to a maximum in acoustic performance for applications requiring an attractive monitor with a small footprint. It uses a brand new ADAM A.R.T. tweeter for frequencies above 2.2 kHz, providing breathtaking authenticity in the reproduction of music and speech. It is an ideal desktop solution for enthusiastic professional and hobbyist audio engineers and multimedia designers in search of no-compromise equipment in their A/V set up either at home or work; and, it is equally well suited for any post production room, home studio or mobile recording facility.
The ANF-10 is a two-way shielded passive monitor that produces unique imaging and outstanding transient response at a very attractive price point. It combines a brand new redesigned A.R.T. folded ribbon tweeter and a 7" woofer in a relatively small bass reflex cabinet. It was primarily designed for small to mid-sized project studios; however, it can also be used comfortably in any application where a small passive monitor is called for, from top-of-the line recording facilities and broadcast/post applications to professional or home surround monitoring.
The P33A is a shielded monitor and has three 100 W amplifiers that deliver outstanding dynamic performance. It can be used either horizontally or vertically, so that very flexible positioning within the studio is possible.
The models S4 are the first to incorporate the A.R.T. Midrange unit. The capability of a loudspeaker to simultaneously create spatial information and good positioning has been the subject of much discussion. Perhaps it is this constant phase behavior of the A.R.T. transducers that cannot be found in voice coil based systems that can accounts for ADAM monitors great ability in this area. The S4 is more than adequate for use in even bigger control rooms with great sound. The S4 is especially suited for broadcast monitoring.
The three-way S4V MK 2 features a 12” woofer, a 5” HexaCone® Midrange and the A.R.T tweeter. The large size of the bass driver combined with 500 W of sheer amplifier power dedicated to this driver alone enable this monitor to deliver low bass information loud and clear. The S4V´s capability to create realistic 3-D sound-scapes makes them the ideal choice for the discerning surround sound engineer.
The S6A MK2 is a real milestone in the history of active main monitors. It combines numerous innovations with great flexibility in compensating for different room acoustics, but foremost it delivers a stunning overall realism in sound reproduction that we consider to be unsurpassed. The woofers and woofer-midrange units carry a HexaCone® diaphragm, a honeycomb structure made of Nomex, coated with Kevlar on both sides, making them lighter and stiffer than possible with classical materials. All drivers are mounted on a 25 mm Aluminum honeycomb plate, that leads to a very close connection between cabinet and drive unit. As a result you get much better impulse coupling that audibly improves the clarity and precision of the reproduction. There’s a dual 15” model as well but for almost all studio purposes, the 6A kicks.
You can mix for hours on these and still hear at the end of the day
You’ll be seeing more of Adam Studio Monitors but if you want to hear them sooner rather than later contact Group Technologies on (03) 9354 9133. Full line information will be on the GT site soon. In the mean time check out www.adam-audio.com
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