Featuring seven drivers, including dual 15" and 9" woofers, plus ADAM Audio’s proprietary X-ART tweeter and midrange drivers, the 2,750-watt S7A MK2 main monitor is designed for very large control rooms and film studios—The S7A MK2 is no longer in production but still supported.
If you’re looking to update your mains or are in the process of building a large facility for recording, post-production, or university-level audio education, the need for wall-mounted main monitors is clear in terms of size, and power, which are essential components in regard accuracy in listening position—particularly in multi-operator setups. While there are convenience factors found with free-standing mains, flush-mounting mains is advantageous for acoustical reasons. Flush-mounting forms an infinite baffle*, which improves the bass response and efficiency and enhances the midrange transient and frequency response. The S7A MK2 main houses seven drivers, which allows a gradual transition across the frequency range, thus correcting the lobe tilting effects found in traditional two-way systems. With that in mind, ADAM Audio designed the S7A MK2 with horizontal symmetry in mind, to produce radiation patterns that provide very consistent reproduction characteristics in the horizontal center position. At the same time, vertical dispersion is reduced so that reflections from the ceiling, floor or mixing console are greatly reduced. As such, early reflections are tamed, which leads to significantly better stereo imaging and a more three-dimensional sound. As a result of this and several proprietary technologies, the ADAM S7A MK2 offers the widest possible dispersion and accuracy, which is crucial for the multi-operator desks common to film production.
ADAM Audio S7A MK2—Just the Facts:
- Two 15" and two 9" woofers in “Extended D’Appolito” speaker configuration
- X-ART tweeter and X-ART midrange driver, handmade in Germany
- Improved driver coupling with cabinet (impulse coupling)
- Six onboard amplifiers; RMS/Music: 2750W/3850W
- Frequency response: 20Hz-50kHz
- Maximum SPL per pair at 1m: ≥138dB
- Room compensation control panel
ADAM Audio S7A MK2—Behind the Grille
The S7A MK2 is the larger version of the S6X and consequently one of the most impressive studio monitors. With a total of 2,750-watt onboard amplification power, this monitor reaches SPL peaks of 138dB per pair at a distance of 1 meter (3'). The larger woofer diaphragms provide more bass volume even at frequencies as low as 20Hz.
The S7A MK2 combines all of the ADAM innovations in the areas of transducer technology, highly efficient PW/M amplification, more detailed control options and the best materials available with an unmatched level of power and performance. This combination of maximum volume with the utmost precision in all sonic areas could only result in one thing: The S7A MK2 is the result of ADAM’s quest to offer the best possible active studio monitor available today.
An active-built complex, large top-class monitor has not yet been achieved because of the challenge presented by the heat generation of the high power amplifiers used in this type of device. In recent years, PWM (Pulse Width Modulation) amplifier technology had significantly improved in that only a fifth of the generated heat has to be dissipated – a real breakthrough in terms of reliability and durability. This allows the S6X and the S7A MK2 to be flush mounted into the studio walls, since all the heat is emitted through the front of the cabinet and the heat sink temperatures remain moderate. Together with the built-in protection circuits the low, constant temperatures of these amplifiers result in reliable performance not possible with traditional AB amplifiers.
In addition to the input sensitivity that can be adapted in the range of ±10 dB, there are four other level controls that affect the individual amplifier modules. Shelving filters at both ends of the frequency spectrum and three fully parametric equalizers help compensate for standing waves in the control room. The EQs can be inserted separately or grouped so their effect can be directly evaluated.
In large film score mixing rooms, there may be a need to simulate theater sound. Based on the ISO 2969 standard, the Dolby® X-Curve is used to achieve this. This filter engages a 3dB per-octave roll-off starting at 2kHz. Below the front input jack is a selector switch that activates this filter, eliminating the need for external processing during the film mix. In addition to the rear input there is an additional switchable XLR input on the front panel, allowing work with the monitor regardless of set-up.
X-ART folded ribbon tweeter technology
Like all models of the AX, the A77X features the ADAM proprietary X-ART tweeter. The “X” stands for “eXtended frequency response,” which is one of the features of Accelerating Ribbon Technology (ART) that has been drastically improved. It now extends all the way up to 50kHz. In addition, the X-ART tweeter has higher efficiency and higher maximum sound pressure levels.
How X-ART works
From its inception, ADAM Audio emerged as a major force to be reckoned with in pro audio monitoring, mainly due to its innovative folded ribbon tweeter. The ribbon tweeter is based on the Air Motion Transformer concept developed by Dr. Oskar Heil, which is a pleated diaphragm similar to the shape of bellows. From the standpoint of surface area response, a 1-inch-wide pleated diaphragm is comparable in function to an 8"-diameter cone. The folded driver acts like a point-source version of a larger driver, which inherently results in lower distortion during sound reproduction. Another property of the folded diaphragm is that its squeezing movement projects air with a speed approximately five times faster than the speed of the ribbon driver itself.
ADAM engineers took this technology and improved on it, incorporating superior geometries and materials to achieve unprecedented audio fidelity. The latest iteration of the ADAM folded ribbon tweeter is the X-ART, which explores new paths in the kinematics of moving air, resulting in a dramatic improvement in the quality of audio reproduction.
The X-ART membrane consists of a pleated diaphragm in which the folds compress or expand according to the audio signal applied to them. The result is that air is drawn in and squeezed out, like the bellows of an accordion.
The ADAM X-ART design overcomes the piston-like motion of all conventional drivers and their inevitable problems, such as narrow directivity, by achieving an improvement in air loading by a factor of 4 over conventional transducers. In addition, the X-ART tweeter’s pleated membrane avoids the typical breakup/distortion and subsequent dynamic limiting at higher frequencies found in dome and cone tweeters. Another positive result of the X-ART design is that the driving “stripes” are in direct contact with the outer air and are cooled immediately.
Diaphragm area is another important factor in determining the dynamic range of a transducer. Basically, what you see is what you get. The cone area you can see is always the acoustically active area of the loudspeaker–this is true for practically all other drive units. By folding the X-ART diaphragm into the 3rd dimension (as seen from the listener’s position) a larger foil can be used, thus increasing the acoustically effective area of the diaphragm by a factor of more than 2.5 times. This results in a higher dynamic output with extremely wide dispersion.
The X-ART midrange driver
Because midrange is the significant frequency band (it’s where nearly all of our music lives), the ADAM development team devoted themselves to building a midrange driver that would do for midrange, what the X-ART tweeter does for high frequencies. It follows, that a similar concept was used to achieve that goal.
The X-ART midrange driver uses a diaphragm that weighs only a fraction of comparable voice coil units, which theoretically enables it to cover a frequency range from 400Hz to 20kHz. The large diaphragm area, comparable to a conventional midrange unit, permits very high, uncompressed SPL without compromising dispersion. The unit has an absolutely flat impedance curve and consequently exhibits linear phase behavior, with a mere ±0.75° deviation within the utilized frequency band.
The result of this technological superiority is unmistakable. There is a special openness that is immediately apparent to the listener when auditioning ADAM monitors utilizing the ART midrange drivers. These monitors are a quantum leap forward in musical accuracy, closely approaching the ideal loudspeaker.
Custom A/B amplifier
While the X-ART tweeter’s solved certain problems associated with conical tweeter designs, its wide bandwidth up to 50kHz, though responsible for the musicality and openness of its high-frequency response, also created a problem in terms of amplification. PWM (pulse-width modulation) amplifiers, which have become popular due to their high power efficiency and low distortion, require a low-pass filter to separate the modulation frequency (the point where power switches from the supply rails) from the audio band. it imposes a limitation on the high-frequency reproduction of the X-ART tweeter. To preserve the wide bandwidth, which in turn preserves the phase coherency and resultant realism of audio in the audible range, ADAM put considerable time and effort into creating a high-frequency power amp to allow the high-frequency tweeter to live up to its potential.
An internal bandwidth of more than 1MHz is externally limited so that the unit delivers an ultra-wide response up to 300kHz, which impacts the audible range due to phase coherency. A signal that’s 3dB down at 25kHz can show a measured in-band phase shift of roughly -50 degrees, which reaches down to 10kHz (frequencies above human hearing do affect the audible range). With nothing limiting the abilities of the X-ART tweeter, the monitor has unsurpassed clarity and openness which will daze and amaze even the most jaded professional ear.
Integral to ADAM monitors, the core of HexaCone woofers comprise a honeycomb Nomex structure that makes them both extremely light and very stiff. The front and back of the cone is coated with Kevlar, which withstands elongation by a force factor greater than 1000 times that of steel, enabling the cone to resist deformation (the source of distortion if all cone-based drivers, such as silk and aluminum dome tweeters).
HexaCone woofers are far more rigid than paper, polypropylene, or aluminum devices of similar dimensions. Due to this rigidity, break up resonances in the diaphragm cone are prevented. The effective length and diameter of the voice coils in conjunction with the size of the magnets and the available cabinet volume are all precisely aligned for a musically optimal low-frequency reproduction.
Another general problem observed frequently in many so-called reference monitors is a disproportionate low frequency volume. With massive woofers (and frequently inadequate acoustic pressure levels!), the average listener is supposed to be impressed. However, this approach results in an inaccurate representation of the overall sound quality. ADAM woofers have been designed to reproduce the given sound material with the highest possible authenticity, guaranteeing ideal translation to the widest range of systems and environments.
PW/M custom amplifier
PW/M (Pulse Width Modulation) also known as Class D amplification or switching amp technology (and mistakenly digital amplification), converts the incoming signal to a series of rectangular waveforms of equal height. The width of the rectangles varies in time and represents the musical signal. This waveform can be amplified much more simply, as the transistors are used as switches that only turn the power supply voltage on and off.
It is possible that a very fast mechanical switch could do the job, but power transistors are a better choice for the task, as such, PW/M amplifiers work pretty much like conventional Class AB designs.
The main advantage of PW/M amplifiers is their extremely high efficiency (>90%). As a consequence the heat to be dissipated is only one-fifth of earlier designs, leading to much lower temperatures within the amps and making the use of heat sinks unnecessary.
While PWM is highly efficient, pulse-width modulation causes signal distortion due to non-linearity of the modulation based on transient response. Usually, some form of noise-shaping filter is required to eliminate the distortion. However, that alone wasn’t good enough for ADAM engineers, who set out to develop PW/M units that would perform at the leading edge of sonic quality while maintaining high efficiency. The ADAM units use a proprietary technology for both the amp and the power supply section (i.e. no more transformers) combined with state-of-the-art input and filter sections to achieve the best in multi-channel active monitoring.
Impulse Coupling (which could easily be misconstrued as hooking up while under the influence of your party demon), actually refers to a basic law of physics as it applies to mounting drivers. Contrary to common wisdom, Sir Isaac Newton didn’t just spend his time tossing apples around at 32 feet-per-second squared (9.8 m2 for you European types). He was also laying the groundwork for studio monitor design. Okay, not really, but the formula for his 3rd law (F1= -F2) governing action = reaction, does form the basis for ADAM’s Impulse Coupling, which is a method that improves the time behavior of speakers based on the physical connection between drivers and a wooden cabinet.
The forces created by the movement of the diaphragm/voice coil assemblies are transferred to the cabinet. However, since wood is not very stiff, these forces cause local instability around the driver, which is a phenomena that keep the drivers basket in motion relative to the diaphragm, thus deteriorating the transmitted sound quality. Imagine if you were to jump in the air; starting from a sand bank gives you a much less stable jump-off point than from solid rock.
Impulse Coupling is ADAM’s way of creating a solid base that improves the reaction of the driver in a comparable way. In both the S6X and the S7A MK2, all drivers are mounted on an acoustically dead, ultra-stiff, 25mm thick aluminum honeycomb plate, which provides an extremely stable mechanical bridge to the cabinet. This superior mount has a positive effect on the driver’s time behavior, which improves clarity, both measurably and audibly.
To ensure that the ADAM Audio S7A MK2 is right for your production needs, call or chat online with your PAD Studio Consultant today.
X-ART tweeter, handmade in Berlin
- Allows longer operation with fewer signs of fatigue
- Their breakup is prevented by the folded diaphragms, distortions are effectively reduced to a minimum
- Advanced dynamic range due to acoustically effective diaphragm surface that is 2.5 times bigger (compared to a classic tweeter according to the piston principle)
The air velocity ratio of 4:1 during the sound generation by folded X-ART membrane
- Direct, fast response in the high-range even with complex transients
Ultra-light but extremely dimensionally stable woofer material
- Excellent transient response even at high sound levels without breakup of the diaphragm
4-way system with 2 x 15" woofer and 2 x 9” midrange
- Very high resolution of the stereo image and extremely wide stereo base
Spacious bass reflex ports on the front
- Bass reproduction with very low compression
Highly efficient PWM amplifiers
- Low-distortion amplification at both low and high volume levels
Linear frequency response of 20Hz to 50kHz
- Unbiased reproduction in a wide frequency band
Maximum peak sound pressure per pair in 1m ≥ 138dB
- Powerful, compression-free sound reproduction even at very high sound levels
Sophisticated room acoustic adjustments
- Allows optimal adaptation to acoustically difficult listening environments or individual preferences
Analog XLR input
- Optimized for balanced line signals
Directional sound radiation in vertical plane
- Reduction of early reflections on the surfaces of, e.g. mixing consoles, desks, etc.
2 years warranty with optional extension to 3 years with the registration of the product
- Full repair service if required for 5 years
- Control panel: Front
- X-Curve filter: Yes
- Frequency response : 20Hz - 50kHz
- THD 90dB / 1m > 100Hz: ≤0.5%
- SPL with sine wave acoustic 100Hz to 3kHz at 1m: ≥128dB
- SPL per pair at 1m: ≥138dB
- Crossover frequencies: 65 / 800 / 3100Hz
- Input impedance: 10k ohm
- Magnetically shielded: No
- Number: 2
- Basket Ø: 15" (380 mm)
- Voice coil Ø: 4" (100 mm)
- Cone material: Paper
- Number: 2
- Basket Ø: 9" (228 mm)
- Voice coil Ø: 2" (50 mm)
- Cone material: HexaCone
- Number: 2
- Type: X-ART
- Diaphragm area: 2 x 26 inch² (16,800 mm²)
- diaphragm Ø: 2 x 5-1/2" (146 mm)
- Velocity transform ratio: 3.5:1
- Diaphragm weight: 0.7g
- Number: 1
- Type: X-ART
- Diaphragm area: 4 inch² (2,420 mm²)
- diaphragm Ø: 2" (56 mm)
- Velocity transform ratio: 4:1
- Diaphragm weight: 0.024 oz. (0.17 g)
- Woofer: 1
- Type: PWM
- Power RMS / music: 1,000W / 1,400W
- Woofer: 1
- Type: PWM
- Power RMS / music: 500W / 700W
- Midrange (cone): 1
- Type: PWM
- power RMS / music: 250W / 350W
- Midrange (cone): 1
- Type: PWM
- power RMS / music: 500W / 700W
- Midrange: 2
- Type: PWM
- power RMS / music: 2x 250W / 350W
- Tweeter: 1
- Type: PWM
- Power RMS / music: 250W / 350W
- Input sensitivity: ±10dB
- EQ 80Hz (Q / Hz / level): 3 x 0.2 - 20 / 20 - 200 / ±12dB
- High-shelf EQ > 6kHz: ±6dB
- Low-shelf EQ < 150Hz: ±6dB
- Sub gain: ±4dB
- Mid-woofer level: ±2dB
- Mid level: ±2dB
- Tweeter gain: ±4dB
- Analog: XLR
- Location: Front/rear switchable
- Weight: 575.4 lb. (261 kg)
- Dimensions (H x W x D): 35-1/2" x 47" x 26-1/2" (900 x 1,200 x 670)
- Warranty: 5 years (2 years warranty plus 3 years optional with product registration)
- Delivery contents: Power cord, manual