The German Physiks range of floorstanding omnidirectional loudspeakers is large, both in terms of scope and the physical size of the biggest models. The really big ones – like the awesome Gaudi Mk II – are huge statement pieces demanding massive rooms and equally massive bank accounts. As a result, we’ve concentrated instead on the more entry level models like the Unlimited Mk II. But, it’s the Borderland Mk IV that is arguably the sweet spot in the range.
The Borderland has long been German Physiks’ biggest seller in the whole range, and it’s not hard to see why: it significantly improves upon the Unlimited and HRS-130 models (they are based upon the Borderland) and set the standard for the substantially larger and significantly more expensive models in the range.
The Borderland was the first model made by the brand and remains something of an archetypal form of the German Physiks concept. From the outset, German Physiks concentrated on using the DDD – Dicks Dipole Driver – to create a true omnidirectional design. The DDD came about as the result of German engineer and mathematician Peter Dicks being heavily inspired by Lincoln Walsh’s brilliant, if fragile and insensitive, drive unit that featured in the Ohm F loudspeaker. While others of his generation were getting into Neu!, Dicks developed a then-almost-unheard-of computer model of the drive unit as an academic exercise, slowly perfecting his own version that finally behaved as the model predicted.
The DDD unit behaves as if it were three drivers in one; pistonic in the lower registers (similar to a conventional cone loudspeaker design). In the midband and the upper midband, it behaves using bending wave radiation, where the voice coil flexes the diaphragm and causes waves to propagate along the whole surface of the drive unit. And finally, in the treble, the driver behaves modally, where specific regions on the diaphragm’s surface are excited and ripple out, a little like pebbles being dropped into still water.
Dicks spent the 1980s honing the design, until in the early 1990s, he began working with audiophile entrepreneur Holger Mueller, who bought the rights to the DDD and then launched the first German Physiks company in 1992 with its first commercial product, the Borderland.
Although 24 years have passed since that first design, the latest Mk IV version of German Physiks’ classic still bears a lot in common with that early design. The original model had a top-mounted titanium foil diaphragm DDD unit, and a pair of 200mm bass units in a push-pull arrangement that vented about 30cm from the top of the cabinet. The Mk IV replaces that titanium foil driver with a more robust and more extended carbon fibre DDD unit, and the twin 200mm units were swapped for a single 300mm unit firing into the base of the loudspeaker in a Helmholtz resonator arrangement. This bass driver is used in German Physiks more upmarket models. This change is possible because the carbon fibre driver has a lower limit of 70Hz, rather than 120Hz in the older titanium foil diaphragm. Factor in the crossover network, and you have a single drive unit that covers the region from 190Hz to 24kHz.
A company that keeps essentially the same design on its books for almost a quarter of a century doesn’t change things often, and the Borderland Mk IV design was first seen in 2007. However, German Physiks performed a substantial re-working of the crossover network last year, and this change was also featured in the HRS-130.