Visiting Audio Group Denmark
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
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
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
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!
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
Mechanical Distortion Reduction
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
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
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.
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
Power Distribution/Grounding, Network Switches
Supplementary Resonance Control Devices
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.
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
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!
Voice: (267) 905-5365