Unicorn MK II

The Unicorn MK II, as its name suggests is a very rare animal: a single driver loudspeaker that covers the entire audio range. It uses one carbon fiber DDD driver to cover the full range from 24kHz all the way down to below 40Hz. Like the Gaudi, it is another German Physiks design that was originally made to prove a point and then became a product because so many people liked what they heard and wanted to place orders. The point in question was to make a full range loudspeaker using a single DDD driver. The result is a loudspeaker with the exceptional resolution, speed and 3-dimensional stereo imaging we have come to expect from all German Physiks designs, plus an exceptionally clean and dynamic bass from the horn system. Bass, wind and string instruments are reproduced with a degree of fidelity rarely heard outside of the concert hall. The overall clarity, coherence and finesse the Unicorn provides make it a dream for lovers of jazz and classical music. It is also capable of surprising rock music fans. If you are a horn loudspeaker aficionado this could very well be the loudspeaker that you have been waiting for.

The Unicorn is a Complicated Animal
Despite its apparent simplicity the DDD driver is a lot more complicated than it looks. It achieves its exceptionally wide operating range by using three distinctly different modes of operation:

Pistonic
Bending wave
Modal

It operates in pistonic mode at the lower end of its operating range. In order for the driver to work in bending wave and modal radiation modes, it must have a comparatively stiff surround.  This restricts the maximum excursion of the diaphragm and hence the low end output. For this reason, in all other German Physiks designs, we cross the DDD driver over to a conventional bass system at around 200Hz.

In the Unicorn, the DDD driver is operated full range. Above about 200Hz it works exactly as it does in all other German Physiks models, but below about 200Hz its pistonic output is coupled to a sophisticated horn system, which allows the response to be extended to below 40Hz.

Ultra Fast Low Distortion Bass
Considerable work went into designing the Unicorn’s horn system. The final design comprises a high gain horn coupled with a tuned bass trap. The bass trap serves two functions. First, it keeps mid frequency energy out of the horn. This would otherwise lead to smearing due to time differences between the DDD driver and the horn, as well as causing a bump in the mid frequency response. Second, it provides a smooth transition between the DDD driver’s bending wave mode where it radiates energy directly and its pistonic mode where the energy is radiated via the horn. To achieve a completely even frequency response in the transition region, a small amount of equalisation is applied to the input signal by a network, which is housed in a separate case. The excellent qualities the DDD driver shows in its normal mode of operation are exhibited in the bass produced by the horn. It is fast, agile and extremely clean with a smoothness of integration with the rest of the audio range that we have yet to hear bettered. There is no hint of bloat or overhang and distortion is impressively low.

German Physiks’ Revolutionary DDD Driver
The DDD driver is a wide bandwidth, omnidirectional driver. It achieves its exceptional bandwidth by the use of pistonic, bending wave and modal radiation: Most loudspeakers use drivers that are purely pistonic. Its apparently simple looks belies the fact that it is able to offer all German Physiks designs a number of very important advantages, which in turn are very beneficial for the listener. These are:

1. Exceptionally coherent and natural sound: The extremely wide operating range of the DDD driver provides an exceptionally coherent and natural sound. This is very difficult to achieve when this frequency range is split over two or more different types of driver, which are in physically different positions on the cabinet.

This wide operating range also eliminates the crossover point in the mid-range that loudspeakers using conventional pistonic drivers must have. Our hearing is most sensitive in the mid-range and avoiding the level- and phase-errors that crossovers can create from this region further improves transparency.

2. Realistic stereo images more like the experience in the concert hall: When you listen to music in a concert hall, you are in an enveloping sound field where much of the sound is reflected off a surface before it reaches your ears. These reflections play an important part in the creation the stereo image that you perceive. Because the DDD driver is omnidirectional, it radiates all frequencies evenly around it and so creates a similar enveloping sound field in the listener’s room.  This way the Unicorn is able to recreate a more natural rendition of the original stereo image. This has excellent depth and focus, but without the overly sharp image definition that some hi-fi loudspeakers produce and which you will rarely if ever hear at a live performance.

3. Stereo imaging enjoyable in almost all positions in the room:  Conventional loudspeakers tend to produce stereo images that can only be best enjoyed from one position in the room, the “sweet-spot”, and then usually by only one person. Move away from the “sweet-spot” and both the stereo image and tonal balance become progressively degraded. This is because conventional pistonic drivers tend to concentrate their radiation into a beam that narrows with increasing frequency.

By contrast, the DDD driver’s omnidirectional radiation pattern enables Unicorn to produce excellent stereo images that can be enjoyed from a wide range of listening positions in the room, while also maintaining a more even tonal balance — much like you would experience at a live performance. This gives more flexibility in where you sit and allows several people to enjoy a good sound simultaneously, so you can share your music with others.

Because you are not restricted to a small “sweet-spot” in order to hear the best sound, the Unicorn provides a more relaxed listening experience. This is especially noticeable when you listen for long periods.

4. Exceptional dynamics: The DDD driver’s very low moving mass provides an excellent impulse response, allowing it to recreate both the attack of the music and resolve low level detail very accurately. The resultant transparency is maintained even on complex high-level passages. For example, cymbals have an authentic initial smash and the ebb and flow of the subtle overtones that follow is clear and unmasked. This ability is essential in order to faithfully reproduce the delicate nuances of a performance and make it sound like music, rather than just good hi-fi. Once you have become accustomed to the more natural presentation provided by our DDD driver, it can be difficult to go back to listening to a conventional design. This is something we often hear from our customers and it has also been commented on in reviews.

5. Accurate portrayal of musical instruments’ tonal characteristics: The DDD driver is phase linear across its operating range, ensuring that the tonal character of each musical instrument is reproduced with great accuracy. This together with the excellent dynamic response enables the Unicorn to reproduce percussion with startling reality. Voices have a clarity and purity that can be breath taking, with all the elements that comprise the vocal sound correctly located in space and with no undue emphasis. The hardness you often hear with conventional tweeters is eliminated and you get a greater sense of hearing a live musician rather than a recorded one.

More information on the DDD driver, its development and advantages may be found on the Technology page of the German Physiks web site at http://bit.ly/1jLZekr

External Equalization Network
Two important benefits arise from housing the equalization network externally. First, it allows for a simpler design of loudspeaker cabinet and second, microphonic effects that might degrade the network’s performance are avoided. Jumpers on the network top 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 construction. A low frequency level adjustment is also provided.

Cabinet Design
We normally try to make our cabinets as rigid and resonance-free as possible, but as we progressed with the design of the Unicorn, we learnt that in fact it was beneficial for certain parts of the cabinet to be able to flex to some extent, in order to achieve the best result. This required quite a lot of experimentation and we found that even the type of finish used in certain parts was important.

This is why the Unicorn looks the way it does. Some people have said that we should make the Unicorn look more beautiful, but we know that if we change the design we will compromise the sound quality and this would defeat the objective of the Unicorn, which is to allow a single DDD driver to give of its best. In any case beauty is very much in the eye of the beholder and pictures do not do justice to the Unicorn. In the flesh it is actually quite a handsome animal. The cabinet’s large panels allow the beauty of complex veneers like walnut, mappa and bubinga to be seen to best advantage. It also looks very good in solid colours like white and carbon fibre is very striking in a room with the appropriate décor.

Hand Finished Cabinets for Ultimate Quality
Because the look of our products is as important as the sound, all our cabinets are built and finished by skilled cabinetmakers for the best possible furniture grade finish.

The Unicorn is available in black or white high-polish polyester; a wide range of high quality veneers in both satin and high gloss lacquer and satin and high gloss automotive paint finishes.

A high gloss carbon fiber finish is also available by special order. Here the cabinet’s MDF panels are reinforced with multiple layers of bi-directional, resin impregnated carbon fibre, applied using techniques originally developed for the aircraft industry. This is then coated with a multi-layer lacquer and hand finished to a luxuriously high lustre.

More details of the finishes available may be found on the main German Physiks web site at http://bit.ly/1lj7U5x.

For product images and the latest version of the user manual, please follow this link to the German Physiks Download Page.

The Unicorn MK II Specifications