PQS-302

The Challenge
Our PQS-402 has been consistently popular since it was first introduced in 2006, but we found that a significant number of potential customers did not have listening rooms that were large enough to allow it to provide its best performance. For these customers we have designed the PQS-302.

The PQS-302 should not be regarded as simply a scaled down version of the PQS-402. It is an exceptional loudspeaker in its own right, with realistic and detailed three-dimensional stereo imaging, excellent dynamics and our trademark fast, deep and well-controlled bass. It goes without saying that it also offers the finesse and transparency that all German Physiks loudspeakers are famous for. Even more impressive is that it combines these attributes with an ability to produce output levels up to 112dB for a more realistic recreation of live-music like dynamics.

The resulting superb sound performance is why the leading German high-end audio magazine Stereoplay has been using the PQS-302 as its reference loudspeakers since 2010.

Fast and Extended Bass
The outward appearance of the PQS-302 bass system is similar to that of the PQS-402. Two bass cabinets are mounted one on top of the other and stand between a top and a bottom plate. None of these components is attached to the other using screws or any form of hard connection. Instead they are held together by a system of interlocking collars. This combined with the fact that the two cabinets have different weights, as do the top and bottom plates, means that resonances are reduced to negligible levels compared to a solid structure. In order to obtain a bass response with the required speed and extension we could not simply scale down the PQS-402 design, so we have employed a totally different approach. Each cabinet houses a single 8-inch woofer mounted on one of the forward faces, with a reflex port situated on the other. This provides a bass with the high speed necessary to match the DDD driver, while also producing a well-controlled and balanced response down to 26Hz.

German Physiks’ Revolutionary DDD Driver
Like all German Physiks loudspeakers, the key to the exceptional performance delivered by the PQS-302 is our carbon fiber DDD driver. Here, this wide-bandwidth omnidirectional driver covers the range from 170Hz up to 24kHz. This extremely wide range is achieved by the use of pistonic, bending wave and modal radiation: Most loudspeakers use drivers that are purely pistonic. The same DDD driver is used on all German Physiks loudspeakers, from our entry level Unlimited MK II, to our top of the range, $300,000 Gaudi MK II. The DDD driver gives the same very important advantages to all German Physiks designs and is what sets them apart from the competition. 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 improve transparency.

2. Realistic stereo images more like you 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 of 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 PQS-302 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 PQS-302 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, making the PQS-302 is truly a “family-friendly” loudspeaker.

Because you are not restricted to a small “sweet-spot” in order to hear the best sound, the PQS-302 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 are 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 Borderland MK IV 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.

Low Resonance Cabinet
The high sound level capability of the PQS-302 meant that extra care had to be taken with the cabinet design to minimize resonances, as these would otherwise degrade the loudspeaker’s ability to resolve the fine detail that is essential in order to produce a sense of realism and hence convey the emotion that is the essence of a musical performance. Consequently, we have borrowed heavily from the design of the PQS-402.

The PQS-302’s DDD drivers use very small enclosures, minimizing the area of any potential vibrating surface. By being cylindrical, they eliminate the resonances that can arise with a conventional rectangular or square section cabinet. Because they are made from aluminum, a comparatively soft metal, residual vibration of the enclosure is minimized. The DDD driver enclosure end-caps are made from non-resonant MDF and the enclosure is packed with damping material to dissipate any standing waves. The result is that the German Physiks PQS-302 has the clarity that we normally associate with electrostatic loudspeakers and for the same reason: they essentially have no enclosure to color the sound.

For the bass system, which covers the range from 170Hz downwards, we also looked to the PQS-402. The system is divided into two independent cabinets, so the panels are smaller and therefore stiffer and more vibration-resistant than if a single large enclosure had been used. All the cabinet vertical surfaces are non-parallel to prevent the formation of standing waves between them. Internal bracing increases rigidity to suppress resonances. Residual vibration is minimized by applying a special damping material called Hawaphon®, to the inside surface of each panel.

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

To damp resonances of the air within the cabinet, the whole of the interior is lined with a 1cm thick layer of high-density felt. This is achieved by fitting pieces of felt that are precisely cut to fit each panel, rather than just inserting a roll of felt into the cabinet. This is a time consuming process, but we believe produces a superior result and is typical of the attention to detail that we lavish on all of our products.

Comprehensive Crossover Adjustment
The crossover provides a wide range of adjustment to allow the PQS-302 to be better set up to suit the user’s listening room. The high frequency level may be adjusted over the range -2dB to +4dB in 4 steps and the low frequency level may be adjusted over the range +10dB to 0dB in 3 steps. Both controls are facilitated by high quality jumpers located on the loudspeaker’s rear panel and may be quickly and easily adjusted.

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 PQS-302 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 fibre finish is also available by special order. Here the cabinet’s heavy MDF panels are reinforced with multiple layers of bi-directional, resin impregnated carbon fiber, 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. As well as looking extremely attractive, the carbon fibre adds an additional degree of stiffness to the cabinet.

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.

PQS-302 Specifications