Borderland Mk IV

The German Physiks Borderland combines the unique carbon fibre DDD driver with a downward firing 12–inch woofer and a sophisticated  crossover network. Housed in an extremely rigid octagonal cabinet, it sets impressively high standards for stereo imaging, transparency and musicality.

Originally introduced in 1992, the Borderland was German Physik’s first flagship model, it was redesigned in 2008 and has since provided the inspiration for the current Unlimited and HRS-130 models. Now in its MK IV form, the Borderland remains GP’s most popular loudspeaker. It combines the unique carbon fibre DDD driver with a downward firing 12–inch woofer and a sophisticated crossover network. Housed in an extremely rigid octagonal cabinet, it sets impressively high standards for stereo imaging, transparency and musicality.

The Borderland MK IV has always been an exceptional performer. The latest version has a new crossover design that provides significantly better bass, with improved integration with the DDD driver, resulting in exceptional top to bottom coherence. The resolution and dynamics have also been noticeably improved, removing another veil between the listener and the music.  All these improvements come together to produce a sound that is truly effortless.

Extended Bass with Low Distortion

The Borderland Mk IV uses a single 12-inch woofer of the same type used in our prestige Loreley model. This provides the Borderland Mk IV with a degree of bass extension normally associated with high quality component sub-woofers. Most impressive is that this is achieved with a cabinet of relatively modest dimensions, making this a loudspeaker that is easy to live with.

The bass driver is located at the bottom of the cabinet and works in a “sealed” enclosure. This enclosure is linked via a small opening to a smaller cavity located at the top of the cabinet. This cavity acts as a Helmholtz Resonator and is tuned to the resonant frequency of the main bass enclosure and ensures a smoother bass response.

Sample tracks on the Borderland IV

Easy room placement

The DDD driver’s omnidirectional radiation pattern and wide operating frequency range make the Borderland MK IV less critical of positioning in the room than conventional loudspeakers, so they are usually very quick and easy to set up. In addition, because the Borderland MK IV is omnidirectional, there is no toe-in adjustment to worry about, which is one less variable to deal with on set-up. The Borderland MK IV will drive rooms up to 90 square metres  (950 sq ft) in size, yet the footprint is a modest 404mm x 404mm (15.9” x 15.9”). 

High Quality Input Terminals

Two sets of high quality WBT nextgen™ loudspeaker terminals are fitted allowing the Borderland MK IV to be bi-wired or bi-amped. High quality jumpers are supplied to enable the loudspeaker to be used with just one set of loudspeaker cables.

Adjustable High Frequency Output

Jumpers on the rear panel allow the high frequency output level to be adjusted in 4 steps: -2dB, flat, +2dB and +4dB. This allows the user to easily compensate for the variations in the absorption of high frequencies that occur due to different types of furnishings and room constructions.

Low Resonance Cabinet Design Enhances Transparency

The Borderland MK IV uses an octagonal cross-section cabinet constructed from heavy panels of MDF, with re-enforcements fitted to critical points within the structure. The use of an octagonal cross-section allows the individual panels to be made smaller and therefore stiffer than they would be if a conventional square or rectangular cross-section were used. This construction minimises the colouration caused by cabinet resonances, which would otherwise degrade the loudspeaker’s ability to resolve fine detail and so reduce its ability to produce a sense of realism.

Residual resonances are minimised by applying a special damping material called Hawaphon® to the inside of each panel. 

Hawaphon® is a polymer sheet containing a matrix of small cells filled with very fine steel shot and was originally developed as an anti-surveillance measure for use in military and government buildings. It adds mass to the panel to reduce the resonant frequency and the ability of the shot in each cell to move against each other provides a very effective way of converting vibration energy into heat. Hawaphon® achieves a broadband attenuation of structure-borne sound of more than 50dB, which is a remarkably high figure. 

Finally, to damp resonances of the air within the cabinet, the whole of the inside of the cabinet is lined with a thick layer of high-density felt.

Designed for a Lifetime of Listening Pleasure

As you would expect from German Physiks, the quality of construction and reliability are first class. The Borderland MK IV is constructed with quality materials and designed for a minimum life expectancy of 25 years.

Where the Borderland MK IV excels is its sonic performance. Within minutes, the listener recognizes that the loudspeaker is special. The three dimensional soundstage and the natural tones of the instruments jump out recognizing that the designer has done extensive work to bring the Borderland to its current state of performance.

The most significant benefit of owning a pair of Borderlands is that you stop auditioning and paying attention to the details of the recording. Instead, you get immersed in the live event and enjoy the musical performance. The omnidirectional capability of the DDD driver allows for enjoyment throughout the listening space and projects a very natural reproduction of human voices and acoustic instruments, even in adjacent rooms. Its speed conveys a truthful depiction of transients and music dynamics. Low frequencies are also vivid, realistic and with grip, contributing to an outstanding musical experience.


4 ohms

Frequency Response
28 – 24,000Hz

Power Handling
Short term 600W

Amplification required
Minimum 160W/4 ohms

Crossover frequency

Crossover slopes
DDD section
12dB/octave electronic & 18dB/octave acoustic
Woofer section 12dB/octave electronic & 18dB/octave acoustic

High frequency adjustment
-2dB, flat, +2dB and +4dB centred at 8,000Hz

86.1dB for 1W at 1m

Operating principle
2-way loudspeaker with 360° surround radiation
using the German Physiks DDD driver

Input connectors
2 sets of WBT nextgen™ binding posts

1 x carbon fibre DDD driver
1 x 12-inch woofer

Recommended room size
15 – 90 square metres
160 – 950 square feet

High polish polyester black or white, carbon fibre
Special order:
Satin or high polish veneer
Satin or high polish paint

404mm W x 1,229mm H x 404mm D
15.9″ W x 48.4″ H x 15.9″ D

54kg / 119lbs

5 years

Other Resources

“Finding an omni-directional speaker that works in real-world rooms can be a challenge. Finding one that is simple to set up, somewhat affordable, relatively easy to drive and sounds like music is near impossible. Yet German Physiks’ Borderland Mk IV, with its Dicks Dipole Driver (DDD) omnidirectional transducer mated to a 12″ down-firing woofer in a sealed enclosure accomplishes just that. The Borderland offers a sense of live music that few other speakers convey. With a single driver reproducing the frequencies from 190Hz to 24kHz, the speaker represents a near acoustic point source, creating a holographic stage that is both palpable and believable. And that 12″ sealed driver truly brings the goods while never losing its grip or unravelling”

The Absolute Sound, Matt Clott, July 2021, link/download

The leading UK audiophile magazine HiFi+ has given the Borderland Mk IV loudspeakers their prestigious Editors’ Choice Award.

When Alan Sircom reviewed the Borderland, the editor of HiFi+ wrote, “The Borderland has all those properties we’ve come to expect from German Physiks loudspeakers, but more so. There’s that outstanding imagery, which is not limited to one place in the room. There’s also that fine top-to-bottom coherence of sound, the extension and grace without an overtly ‘audiophile’ faux sound, and so on. But with the Borderland, this all comes together with a larger, more physically ‘in the room’ presentation that is as potent as it is beguiling.”

Alan concluded that, “… the German Physiks Borderland Mk IV represents an exciting, musically energetic and live-sounding experience, more like the real thing than many loudspeakers.”

Alan Sircom, HiFi+, Issue 141, 2016, link/download

“Who Knows Where The Time Goes” on Eva Cassidys’ Imagine re-enforces this lilting portrayal of dynamic shading. From a whisper to a roar, the track displays all that we audiophiles and music lovers alike get giddy about. Guitars push to their limit, as does Eva’s voice midway through the song, yet the quiet moments contain just as much entertainment value and feel every bit as alive. Easier said than done…..Stellar top-to-bottom coherency, speed and dynamics make for a solid foundation upon which the bass with its power, speed and pitch make it a bass-freaks’ master. The rest of the spectrum is just as well rendered with an infinitely open and detailed sound.

Greg Petan, Dagogo, 2011, link/download

Borderland design evolution

The original version of the German Physiks Borderland, the Mk I, was introduced in 1992. It was the first loudspeaker produced by German Physiks and the first loudspeaker to use the then newly developed DDD driver. It used an octagonal cross-section cabinet, with a single titanium DDD driver mounted on the top, but there the similarity with the current Borderland Mk IV ends.

Unlike the current Mk IV, the cabinet was constructed in two parts: an upper cabinet for the DDD driver and a lower cabinet for the bass system. 

The bass system itself was also totally different to the current Mk IV. It employed two 8-inch woofers in an isobaric arrangement. These were clamped together by a thick threaded bar that ran the length of the bass cabinet, passed through the centres of the woofers and terminated inside the upper cabinet, thereby also securing the two cabinets together. The bass energy was radiated from a circumferential opening located between the two cabinets. The detailed construction of the loudspeaker is shown in the diagram below.

Because at this time German Physiks was a new company, it took a while for the word to spread about this novel loudspeaker, but the word did gradually spread. At the numerous demonstrations we carried out, listeners were struck by the exceptional coherence and transparency offered by the DDD driver and the fast and well integrated bass offered by the twin woofers. The Borderland Mk I began to sell well in a number of markets, especially in the Far East. 

The basic design continued through the Mk II and Mk III versions until 2008, when the Borderland Mk IV was introduced. Throughout this time, the Borderland has been our best selling product in practically every market. It has an ideal mix of attributes. It provides a very high level of performance at its price point; the cabinet is comparatively compact so it fits easily into most rooms; it is not an unduly difficult load to drive, allowing it to be used with a wide range of electronics and it can work well in a wide range of room sizes – 15 sq m to 90 sq m (160 sq ft to 950 sq ft).

In 2008 the design was radically revamped with the introduction of the Borderland Mk IV. The octagonal cross-section cabinet was retained, but it was constructed in one piece rather than two. The isobaric bass system was replaced with a single downward firing 12-inch woofer, located at the bottom of the cabinet.  This was operated in a sealed enclosure. The use of a 12-inch driver gave the bass extra weight, improving the low end balance and a new bass system provided better transient response with improved integration with the DDD driver.

The crossover frequency was lowered from 270Hz in the Mk I, to around 200Hz. Increasing the range of the DDD driver gave an improvement in coherence, as it was now covering even more of the audio range.

Another innovation in the Borderland Mk IV was the introduction of a Helmholtz resonator in the bass system. This consists of a small enclosure located at the top of the bass enclosure and coupled to it by a small hole. This is filled with damping material and is tuned to the resonant frequency of the main enclosure. It acts as a Helmholtz resonator and suppresses the main enclosure resonance, which would otherwise cause a bump in the bass response. The result is a smoother low-end response.