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This review first appeared in the August 2010 issue of hi-end hifi magazine High Fidelity of Poland. You can also read this review of the German Physiks HRS 120 in its original Polish version. We publish its English translation in a mutual syndication arrangement with publisher Wojciech Pacula. As is customary for our own reviews, the writer's signature at review's end shows an e-mail address should you have questions or wish to send feedback. All images contained in this review are the property of High Fidelity or German Physiks - Ed.

Reviewer: Wojciech Pacuła
CD player: Ancient Audio Lektor Air 
Phono preamp: RCM Audio Sensor Prelude IC
Preamp: Leben RS-28CX 
Power amp: Luxman M-800A
Integrated amp: Leben CS300
Loudspeakers: Harpia Acoustics Dobermann
Headphones: AKG K701, Ultrasone PROLine 2500, Beyerdynamic DT-990 Pro 600 Ω
Interconnects: CD-preamp Wireworld Gold Eclipse 52, preamp-power amp Velum NF-G SE, speaker cable Velum LS-G
Power cords: Acrolink Mexcel 7N-PC9100 (CD) and 2 x Acrolink Mexcel 7N-PC7100 (preamp, power amp)
Power conditioning: Gigawatt PF-2 Filtering Power Strip
audio stand Base
Resonance control: Finite Elemente Ceraball under the CD, turntables change continuously, as do cartridges
Review component retail: 95.000zł in Poland (ca. €23.630)

The first German Physiks speaker model from what is obviously a Teutonic firm appeared on the market in 1992. But as their materials state, R&D commenced as early as 1978 when Peter Dicks—engineer, mathematician and sociologist —became frustrated with available audio transducer solutions. Being a researcher, he wanting to resolve this problem systematically. By 1980 he had developed a prototype of a completely new type of transducer. More importantly, this was accompanied by a complex mathematical model of its operating principle which he developed in parallel. To be clear, this was not the work of an enthusiast amateur who can occasionally end up with splendid but fundamentally still limited outcomes. No, this was a proper scientific research project that combined advanced math and Physics, computer modeling and much prototyping.

As such the project began wholly on paper before any material experiments confirmed its developing theory in working practice. While this simplifies the actual process involved, this background becomes key to properly understanding the DDD Dicks Dipole Driver. It’s conceptually based on a famous predecessor developed after WWII by the American Lincoln Walsh whose invention became consequently known as the Walsh driver.

Convinced he’d discovered the holy grail of audio, Peter Dicks tried shopping his advanced driver solution to European speaker and transducer manufacturers. Despite enthusiasm and a strongly documented scientific background, nobody appreciated his solution sufficiently to stop doing what they already did – build classic dome & cone drivers. The only avenue left for Dicks was go solo.

Transitioning from a working prototype to a production model—more or less contingent on the target market size—is usually a very costly process to require outside venture capital. Fortunately for Peter Dicks one man embraced the proposition and risk to invest significant funds into a new company. This was Holger Mueller, audiophile, IT specialist and owner of Mainhattan Acoustik. At first they sold classic loudspeakers designed by Dicks in the early 90s. Naturally Mueller was mostly interested in the DDD. That’s because he already owned and loved the Ohm F speaker which contained a version of the original Walsh unit. Mainhattan Acoustik then acquired Peter’s license and German Physiks was born. Now the two engineers split roles. Dicks began fine-tuning the mathematical model and Mueller investigated its practical applications and came up with an external design. It took two years to work out all complications and implement a fully optimized production driver. By 1992 German Physiks began to sell the Borderland speaker model to formally launch the brand on the international hifi scene.

The entire raison d’être for the formation of German Physiks was clearly the DDD. Right away one sees how radically different it is from the norm. In fact my first reaction during one of the High End Munich show installments was probably no different than the makers Dicks approached originally. I just saw yet another hifi oddity. Considering the reactions of acquaintances who visited me during this review of the HRS 120 Carbon, I was not alone in this.

On to the driver. The DDD is a long, narrow Titanium or carbon-fiber cone reminiscent of an upside-down conventional albeit unusually steep or elongated driver. This places on top a strong magnet, voice coil and impregnated fabric spider and on the bottom a rubber suspension. External connection of the upper and lower parts is via eight exposed spacer pins. Driver dimensions are an 212mm height coupled to 264mm and 220mm diameters on bottom and top respectively. Weight is 6.3kg. Bandwidth is 70Hz to 24kHz with 50-watts max power and no crossover. Robert Kelly, head of sales at German Physiks, describes the driver in more detail in this SideBar.

Roughly—and disregarding its actual shape and orientation—the DDD to the eye seems very much an inverted conventional cone driver. One clear difference despite its ‘dipole’ epitaph is plain. Here we deal with omnipolar 360° dispersion. Not apparent to the eye is the driver’s operational behavior. That in fact has nothing in common with classic cone drivers whose entire diaphragms respond—theoretically as an idealized piston—uniformly to any signal that’s applied to their voice coils. In stark contrast the DDD’s mode of operation breaks down into three distinctive bands with mechanical subdivisions. The lowest frequencies are described by known Thiel/Small parameters and work as a classic cone driver. The following band generates expansion modes from driver bending; and the last band creates deliberate standing waves whilst the diaphragm breaks up in carefully controlled fashion. A proper description of these behaviors requires a mathematical understanding that’s well beyond me so we’ll leave it at that. The segregation into three bands of different propagation behaviors is achieved with special materials, cone geometry and such.

Currently the company offers two versions of the DDD. One is made from 0.025mm titanium foil, one from 0.15mm woven carbon fiber. This review reports on the second version and an enclosure option where carbon fiber also becomes external skin for the underlying MDF of the octagonal core. The HRS 120 is a two-way floorstander with DDD on top and a conventional floor-firing 250mm woofer on the bottom. The latter works in a sealed loading and couples to the outside world slot-loaded by the integral plinth and vented through its circumferential openings. The DDD crosses in at 240Hz with a 12dB filter and third-order acoustic function, the woofer at 24dB (2nd-order electrical + 2nd-order acoustical). Overall dimensions are 320 x 1145 x 320mm WxHxD, weight is 65.3kg/pr. Claimed frequency response is 29Hz to 24kHz. A low-ish 87.2dB sensitivity mandates powerful amplifiers. The company recommends a minimum of 100 watts into 4Ω.