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March 2023
Visiting Audio Group Denmark
(AGD)
A technology overview of remarkable products.
Manufacturer Visit Report By Greg Weaver
Scandinavian Ascendancy
If you've been paying attention to recent industry trends, you'll be aware that the
Audio Group Denmark's three audio product lines, Ansuz, Aavik, and Børresen
Acoustics, have been getting a shite load of attention of late. And if
you've followed my show reports here, you've seen my highly favorable coverage
of them several times now, from my inaugural Pacific Audio Fest report to my
Capital Audiofest coverage, where they stole the show with the introduction of
simply remarkable $11,000 Børresen Acoustics X3 loudspeaker. This sleek,
sexy-looking, small foot-print loudspeaker was driven with something on the
order of another $90,000 worth of their Aavik electronics and Ansuz cabling,
power and grounding solutions, network switches, noise suppressors, and
resonance control devices. And – it was stunning!
When I learned that I would have the opportunity to visit the Audio Group Denmark's 25,000 square-foot production facility in Aalborg the third week of January this year, I was totally stoked! Besides getting to tour their entire state-of-the-art facility – and to make a video record of it, I would get to audition loads of their products, some of which were still in development as prototypes, to interview Michael Børresen and Flemming Rasmussen, and get the full four-one-one on all the technologies and techniques they were implementing to globally reduce noise and dampen resonances.
The opportunity to visit Denmark simply amplified my already animated state of excitement about this trip! I must share that I have had the desire to visit this part of the world since learning about the Viking age and reading Shakespeare's Hamlet in middle school. Yeah, this was going to be a dream come true.
My plane landed at the Aalborg airport after more than 19 hours of travel, from South Bend, Indiana to Atlanta, Georgia to Amsterdam, Netherlands, and finally on to Aalborg, Denmark. I was met by the Founder and CEO of AGD, Lars Kristensen, whom I've had the pleasure of knowing for some years now, going back to when he was still with Nordost. When you have the pleasure of meeting Lars at a show or promotional event, you will find that his cordial demeanor, astuteness, sociability, and passion combine to make him not only the perfect ambassador for their brands, but a genuinely fun cat to spend time with.
We chatted briefly during the 15-minute commute to my hotel, the Radisson Blu, situated just one block off the historic and beautiful Limfjord. While Lars parked his exhilarating ride, a dark blue BMW M4, I had time enough to check into my room and freshen up a bit after my long day of travel. I met Lars in the lobby, and we walked just a few blocks to the Bistro V, where, joined by his charming wife, Iben, we dined on some of the tastiest "Fish & Chips" I've had in years.
After a cocktail or two and making plans to meet and start my real adventure first thing the following morning, we said goodnight, and I headed back to my hotel to crash. I had been up since 6:00 AM EST and had gotten on a plane in South Bend, Indiana, at 4:00 PM EST on a Monday. Now, after having been up for some 33 hours (save some inadequate cat naps on the flight to Amsterdam), and traveling for the past 23, by 9:00 PM CEST Tuesday, I was ready for a nap!
Behind the Curtain
Lars collected me from the hotel at 9:00 AM on Wednesday, and my astonishing
adventure began as I entered the 25,000-square-foot AGD facility. It is not
coincidental that, over many conversations with both Lars and Peter Hansen, AGD's
Area Sales Manager for North America, I had been exposed to the core guiding
principles behind all their designs, principles that are implemented to some
varying degree, from rudimentary to fullest possible effect, in every
product that they produce.
And while I have heard a good number of their products over the past few years, and had established a fairly well-rounded base understanding of what they were doing, and why, my one-on-one time in Aalborg allowed me to acquire a much deeper understanding and appreciation of these design philosophies, their application, and the aggregate performance enhancements that their integrated application offers. Let's dig into the particulars of each of their signature approaches and see if we can't begin to understand more clearly what they are doing, what makes them so effective, and how these products have made such an enduring impression on virtually everyone who gets the opportunity to hear them!
Conquering the Adversary – Inductance
First and foremost, the underlying, almost singular design goal of AGD is to
eliminate, or to at least radically reduce at all turns, inductance throughout
the entire reproduction chain. Why? Simply put, inductance can be seen to have a
direct correlation to noise, which contaminates and destroys the purity
of the audio signal.
While it may sound as if this would be an obvious consideration, every manufacturer has their own "unique" approach to reducing self-generated or induced noise, allowing them to deliver the highest level of performance they can attain. But they don't all focus on, or address, the same concerns. Even when two manufacturers do find themselves addressing the same issues, they rarely approach how they choose to resolve the challenge from the same perspective or use the same methods to find solutions. And adhering to their individual choices gives them a "distinction" from other similar manufacturers, and thereby, a story to tell as to how and why their products differ from their competition. In their battle to overcome inductance, AGD applies a multi-pronged approach, one that you will see is both unusually complete and complex. Spoiler alert – their methodology is remarkably successful!
Exotic Metals / Materials
After a closer examination of many of the most commonly used materials in the
fabrication of most audio products, they quickly realized that they weren't fond
of the intrinsic "sound" of aluminum, especially when used in such common roles
as a component chassis or in any capacity anywhere near a loudspeaker. In fact,
given all that they have learned through their independent testing and
evaluation, Lars is fond of pointing out that if aluminum has such excellent
sonic properties, why doesn't anyone make musical instruments out of it?
He further points out that while it isn't possible to eschew the use of aluminum completely, they use as little as possible, and only where it will have a minimal impact. Lars goes on to suggest that by reducing the aluminum content in their products, they are reducing induction. In place of aluminum, they have chosen to implement a number of other materials, including chassis made of non-metallic composites, and where metal is required, they implement stainless steel, copper, silver, gold, titanium, or most notably, zirconium.
In fact, one significant contributor to the significant cost of the flagship speaker is the use of laser printed zirconium speaker baskets. Lars showed me some in the assembly and test area and commented that they were just about $3,000 each!
Iron Distortion
Staying with the discussion of the sonic contributions of various metals, iron
is commonly used in the construction of motors for loudspeaker drivers today.
Much like their findings with their independent study of the sound of aluminum,
they questioned the use of iron, and decided to do something about a matter
referred to as "iron distortion." Lars explained that if your purpose is to push
the performance of loudspeakers to new levels, then you have to consider solving
the non-linear behavior of traditional drivers due to the presence of iron.
During our conversations, he was quick to point out that until now, no one else
has successfully addressed this problem.
They felt very strongly that this was a distortion that they had to address in order to take their speaker performance to the next level, and as such, with time, Michael Børresen has designed and patented the iron-free magnetic motor; a method he continuously works to improve and refine. The result of this iron-free magnetic motor design is a reduction of inductance that is about ten times lower than that of conventional drivers! As such, the brand now uses iron-free driver motors in all of its loudspeakers.
Silver Faraday Rings
Wanting to push the envelope to its limit, to reduce inductance even further,
the Børresen engineering team replaced the typical copper Faraday, or shorting,
rings, used to absorb the magnetic fields radiated by induction coils, with
in-house, handcrafted, highly treated, silver versions. They buy raw Sterling
Silver, and using an individualized sand-casting process, heat the silver ingots
to 1100 degrees Celsius, and pour the molten metal into individual sand-cast
formers. Once they have cooled, they process and polish these exotic shorting
rings.
Mechanical Distortion Reduction
And as if that weren't enough, these bespoke silver parts, along with other
speaker parts like the four one-hundredths of a millimeter thick titanium skin
layer that goes on the M series driver cones, are shipped off to the Danish
Technological Institute in Aarhus, some 120 Kilometers to the south. There they
are bombarded with Titanium Nitrate, Tungsten, and/or Zirconium for up to 92
hours using a sophisticated, high-energy process to modify the surface structure
of the materials being treated, subsequently diffusing these other metals into
those base materials.
The result of this additional exotic and expensive process is the accretion of fine layers of these other more exceptional metals upon the base metal parts is said to have an extremely positive effect on reducing their mechanical distortion properties. This transformation affords even further reduction of inductance, allowing them to achieve an unprecedented new minimum level – one that they say is about 12 times lower than the inductance level of conventional, iron-based drivers! However, because of the remarkable expense incurred in the fabrication and application of these last two advantages (bespoke silver ringed drivers and the other plasma-plated materials), these Silver Supreme Editions are only available in the 0 series of loudspeakers.
Augmented Class A Amplification
And while we are on the matter of the selected application of advanced
technologies, the newest flagship lineup of their amplifiers have implemented a
unique augmentation of Class A circuit topology. While most Aavik amplifiers
employ Class D amplification because of its efficiency, light weight, and
exceptional sonic properties, they have adopted a more absolute approach to the
use of Class A in their 880 series of integrated, mono, and stereo amplifiers.
Michael contends that even the most stringently designed Class A amplifiers at some point give way to Class B operation, where the output devices are no longer constantly on, and revert to some level of switching. Michael attributes this to a known operational property of transistors. He explains that current is used for the base of the transistor – and because that leg is quite often leaky, the current drain will run through the base and out through the emitter to the signal. His reasoning is that the forward bias used to drive the transistor varies routinely and may diminish significantly under the greater load of higher volume demand, meaning that some of the current is actually coming directly from the bias stage.
The reinterpretation of Class A that Michael and Flemming have implemented uses a multiple approach. First, they apply a significantly higher margin, or spread, of bias current difference between what is needed to keep the devices merely forward biased, operationally in Class A, and to actually drive the audio signal under arduous loads.
In addition, to better maintain the stability of that elevated current margin across its full operational output, rather than employing a simple resistor between the base and collector of the transistor to provide the bias voltage (we'll ignore its negative feedback component in this example), they employ a diode matching the one used at the output of the transistor to provide considerably more consistent and stable current flow under even the most demanding of loads.
Inverted Tesla Coils
Next up, one of the more unique tools in their arsenal to combat inductance is a
new component they have both developed and fabricated in-house, something they
call a Tesla coil. The key operating principle uses a matching pair of coils,
wound in opposite directions – one coil and one counter coil, in essence, a
double inverted coil. As Michael explained, these inverted Tesla coils
are essentially a transformer inside another transformer, wired in opposing
polarity. This allows them to drastically reduce the voltages they see. By being
able to do so with high-frequency noise spikes, they can transform them down,
and that reduction then allows them to very effectively cancel some of the
high-frequency noise encountered, whether it was introduced via the mains or
comes from some other residual origin, like cabling.
According to the information at their site, both coils carry voltage, and when one of the Tesla coils encounters a voltage spike, a counter spike is activated to eliminate the noise. Since noise spikes are pure voltage carrying virtually no charge, even though the resultant cancellation is quite good, it alone is not perfect. The addition of many Tesla coils in parallel increases their effective noise cancellation, elevating the degree of the perceived blackness from which all the music emanates, and significantly increasing the overall purity and clarity of the sound.
A closer look reveals that AGD uses several different types of these Tesla coils, as their individual properties ideally complement and reinforce one another. There is the passive Tesla Coil Technology (P-TC), used in a noise suppressing role that focuses on mains power spike noise cancellation and works by having their double inverted coils connected to the power conductors.
Next is the first Active Tesla Coil Technology (A-TC), a powered rather than passive version of the P-TC, which are about three to four times more efficient than the passive variety. Then there is the Active Cable Tesla Coil Technology (AC-TC), and while it is similar to A-TC, where the A-TC technology is mounted on circuit boards, AC-TC coils are mounted directly around the mains conductors to further enhance their effectiveness. The last implementation is called the Active Square Tesla Coil Technology (AS-TC). While also similar to A-TC, where the A-TC technology is mounted on the circuit boards, these AS-TC coils are embedded in the circuit board itself. While this application may not be quite as efficient as the A-TC method, it is much more compact overall, and considering their impact, are more cost-efficient.
Analog Dithering
In combination with these innovative inverted Tesla coils, they have also
introduced a new analog dithering technology across a wide range of their
products. During our interview, Michael explained that this technology was first
recognized during WWII, as radar or sonar systems used on objects that were
physically moving, like those on ships or aircraft, consistently delivered
notably more accurate readings than those taken from stationary land-based
systems. The conclusion was that the vibration of the planes or ships aided the
radar or sonar performance.
AGD applies this understanding to further minimize system noise with the application of this analog dithering. This dithering works by injecting a very low-level amount of random noise. Then, by modulating the noise floor, it becomes possible to uncover information that is normally concealed beneath that floor. In their case, they use a process that mathematically removes harmonics and other highly undesirable distortions, entirely replacing them with a constant, fixed noise level. The result is a clearer picture of the full content of the recording.
Anti-Arial Resonance Coil Technology
Another trailblazing technology that they developed for use in their cables and
cable screens is called Anti-Arial Resonance Coil technology (AARC). All cables
are in essence, antennas. By fitting AARC into their cable architecture, it can
significantly reduce each cable's ability to absorb airborne RF/EMI. Though AGD
doesn't specify exactly how they accomplish the feat, this technology is said to
somehow prevent the cable from appearing to have a definitively fixed length.
This ambiguity diminishes the ability of the treated cable or internal wire to
act as an antenna, preventing any waves, standing or otherwise, from being
intercepted by the cable and bleeding into your system.
Power Distribution/Grounding, Network Switches
Ansuz also makes a series of power distribution and grounding systems and
network switches, all of which incorporate varying levels of these effective
technologies. Their entire lineup of AC, digital, interconnects (single-ended
and balanced), Ethernet, and speaker cables, as well as those power distribution
and grounding systems and network switches, all employ them to varying degrees
and with increasing effectiveness as more and more combinations of layers of
their inductance minimization strategies are implemented.
Supplementary Resonance Control Devices
The Ansuz product lineup also includes several other interesting devices aimed
at providing even more effective audible noise reduction. Many of you may recall
the "shorting plugs" that rose in popularity in the 1970s. They were essentially
an RCA connector with its signal and ground pins shorted together. Inserting
them into the unused inputs on preamps and other devices helped to block
radiated noise from making their way into that unused input.
The Ansuz Sortz products take this idea to an entirely new level. They are termination plugs meant to be used with any open input or output socket in your system. By combining the Tesla coil, to reduce the ability of your component to pick up disturbing noise, the anti-aerial resonance coil technology, which significantly reduces the introduction of RFI and EMI-based noise levels, and effective grounding, when they are plugged into open jacks, they can be heard to significantly reduce otherwise unchecked background noise levels.
Further, their diverse lineup of Ansuz resonance control isolation devices, designed as component footers, are called Darkz. A single Darkz footer measures 1 ¾" wide and just shy of an inch tall and is comprised of a layer of three discs. Each disc has three dimples - spaced equidistant (every 120°) - on its top and bottom surface and is separated and isolated from the one above or below by the use of three small metal ball bearings, residing in and held in place by the disc dimples. Moving through the Darkz lineup, you move to more and more effective isolation materials, including titanium and zirconium.
Cryogenics
Finally, Audio Group Denmark cryogenic treats many of its products constituent
components, from crossover parts like coils to speaker parts like baskets,
magnets, rings, and even some driver cones, to further reduce inductance. When
these metal crossover components and premium drivers undergo cryogenic
treatment, inductance is reduced by an additional 6 to 8%!
Those who have experienced the aural benefits derived from cryo treatment will appreciate the resultant synergistic sonic possibilities obtained by any audio components constructed using such affected parts. I have been aware of both the measurable and audible results that super cooling items by immersing them in a bath of liquid nitrogen (at temperatures approaching minus 200° C/minus 320° F) for an extended period can provide for decades now. AGD says that they find further diminished inductance in the range of 8 to 10% after such treatment!
It All Adds Up
I think you can acknowledge that this is one impressive array of technologies,
more than ten outlined herein, all aimed at the reduction of inductance, and
thereby, its related reduction in noise and related distortion-causing
components. I have outlined these many approaches, the bulk of which would
appear to be unique to the product lineup from AGD. In all fairness, other
companies utilize vapor deposition and cryogenic treatments.
While even the entry-level products from each of the Aavik, Ansuz, and Børresen Acoustics product lineups employ some level of their myriad strategies, stepping up through each tier of the entrants available from each product line reveals the implementation of more and more layers of application of these various technologies, yielding greater and more effective noise suppression.
By way of just how effective their approach is, the degree to which their entry-level products demonstrate the successes of their global approach, in particular the $11,000 Børresen X3 loudspeakers - driven by even their new, entry-level $5,000 Axxess integrated amplifier, is simply astonishing! I've yet to speak with any listener who has heard this loudspeaker who is not as completely taken with their unexpected and astonishing degree of performance as I was. Seriously, had I been told that the X3 had a retail of $20,000, I would still be struck by its overachieving level of accomplishment.
The combined effect of all these individual elements was to be borne out, over and over, during my many listening sessions over the length of my visit. While I cannot speak to the individual efficacy of any single one of their methods, what I can say - without question - is that the synergy of their combined application is undeniable!
I'm reminded of the comment Polonius makes to Laertes in Act 1, Scene 3 of Shakespeare's Hamlet, "If we are true to ourselves, we can not be false to anyone." So it would appear to also be with the efforts of AGD. By following their instincts, exploring and pioneering new and innovative methods of problem-solving, and staying true to their goals and beliefs, they are building products that reveal music with as much truthfulness as they know how.
As much as I had been taken with what I had heard from my sampling of AGD products prior to my visit, I have to admit that I was quite taken with much of what I got to hear before I left. To that end, Lars and I discussed my reviewing a number of these remarkable products, some of which are still in development. Be sure to keep an eye out for my auditions of each and every one of these remarkable products that I may have the opportunity to experience in my reference system. In fact, I've been told to expect a visit from Peter Hansen, AGD's Area Sales Manager for North America, just as soon as the new Børresen X3 loudspeaker is put into regular production! That may happen as early as next month!
In the interim, if you have the opportunity to hear any of these products, at a show, in a retail environment, or in any professional or private installation, go out of your way. Once you do, I've no doubt you will understand why these products are making such an impression everywhere they show up!
Company Information
Aavik Denmark / Audio Group Denmark
Rebslagervej 4
9000 Aalborg Denmark
Voice: 45 4051 1431
E-mail: info@audiogroupdenmark.com
Website: AudioGroupDenmark.com
USA Distributor
Audio Group Denmark USA
Perkasie, PA 18944
Voice: (267) 905-5365
E-mail: ph@audiogroupdenmark.com
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