A close-up on the
German Physiks
PQS-302

Welcome to the March 2023 German Physiks newsletter.

This month we would like to take a closer look at the PQS-302, our most popular larger loudspeaker. This model is the bridge between our single DDD driver and multi-DDD driver designs. It offers a significant improvement in performance over the model below it, the Borderland Mk IV, yet its cabinet does not take up much more space on the listening room floor. The leading German audiophile magazine Stereoplay was so impressed with the PQS-302 when they first heard it in 2010, that they have been using it as a reference ever since. A number of updates have ensured that the PQS-302 has maintained its position relative to the competition.

German Physiks PQS-302
- overview -

German Physiks PQS-302 in matt white

The PQS-302 is designed to offer a significantly higher level of performance than the model below it, the Borderland Mk IV. If you have heard a Borderland you will know that this is quite a high bar. It is also designed to be able to drive larger rooms and produce a higher maximum output level. To do this it uses two carbon fibre DDD drivers and a larger bass system. These are arranged in a similar configuration to that used in our PQS-402, Loreley and Emperor models.

Sensitivity is a moderate 87.7dB and like all German Physiks designs the impedance characteristic is fairly benign. To get the best from it a solid-state amplifier with good current delivery is recommended. These days this describes pretty much any good quality audiophile solid-state amplifier. Brands we have seen good results when paired with our loudspeakers include: Accuphase, Accustic Arts, Audia Flight, Ayre, D'Agostino, Gryphon, Karen, McIntosh, Mola Mola, Pass, Spectral, Viola, Vitus, YBA and Ypsilon. As you would expect, we also recommend our own Emperor range of amplifiers.

Visit the PQS-302 web page

Visit the PQS-402 web page

Visit the Loreley Mk III web page

Visit the Emperor Mk II web page

Visit the Emperor electronics web page

Two carbon fibre
DDD drivers

The two carbon fibre DDD drivers operate in parallel and are flat from 170Hz to 24kHz. Despite the DDD driver having a conical diaphragm, it acts like a pulsating cylinder and it is phase linear over its operating range. This means that the phase relationships of all the frequencies in the DDD drivers’ very wide operating range are accurately preserved. This is not the case in loudspeakers that use several different drivers to cover different parts of this range, as the different distances between these drivers and the listener’s ears inevitably results in their contributions being slightly time delayed relative to each other. This compromises the timbal accuracy and the transient response. The effect will depend on the actual design of each loudspeaker, but even if the designer has skilfully minimised it, it is present none-the-less and if it can be avoided, fidelity will be improved.

The PQS-302’s excellent timbral accuracy and outstanding transient response are easily appreciated. The very natural portrayal of vocal music, especially female vocal will highlight the excellent timbal accuracy and percussion instruments will demonstrate the PQS-302’s excellent transient response. Snare drums have an authentic crack to their attack. When partnered with suitably fast electronics the speed with which the PQS-302’s DDD drivers can reproduce transients can make you jump.

We experienced a very good example of this during a demonstration at a dealer a while back. We were using a different German Physiks model, but it had the same carbon fibre DDD drivers as the PQS-302, so the comparison is valid. We played a test CD made by the US magazine Stereophile. One track, intended to demonstrate transient response, featured a wine glass being smashed. First we played the track with the loudspeakers being driven by electronics made by a very well known and respected US company. The track indeed sounded like a glass being smashed. The dealer then connected a pre and power amplifier made by the US company Spectral. This is a very well respected, but now rather niche company, famous for the exceptional speed of their electronics. The sound of the glass breaking was noticeably more realistic and every time we played this track we flinched. Even when we knew this track was coming up we could not stop ourselves from flinching. This demonstrates the exceptional speed of both the Spectral electronics and the DDD driver. The DDD driver achieves this exceptional transient response due to its very low moving mass, which is less than 3 grams.

The maximum output level of the PQS-302 is 112dB, which combined with its exceptional timbral accuracy and transient response helps to give the listener the feeling that they are listening to real musicians rather than just good hi-fi.

Bass system

The bass system comprises two separate cabinets. Each has an 8-inch woofer on one face and a bass reflex port on the other. The relatively low moving mass of the 8-inch drivers provides a fast bass that integrates well with the speed of the DDD drivers. The use of a bass reflex system allows a relatively small cabinet to produce a bass response that is flat to 26Hz.

The angled front faces of the bass cabinets act as diffusers for the rearward radiation from the DDD drivers. This allows the PQS-302 to be positioned against the wall if needed.

The inside surfaces of the bass cabinets are also veneered, albeit with a lower quality one than used on the outside. This ensures dimensional stability and stops the cabinet panels from warping even after many years.

Comparatively compact

Borderland Mk IV in carbon fibre PQS-302 in walnut veneer

Despite its larger bass system and two DDD driver array, the PQS-302 is not much larger than the Borderland Mk IV, as can be seen from the picture above. It is 126 mm (4.9”) wider, 171 mm (6.7”) taller and 260 mm (10.2”) deeper, so it will fit into medium size rooms. For the level of performance it can deliver, it is comparatively compact.

The PQS-302 can work in a wide range of room sizes, from 25 to 100 sq m (264 to 1,267 sq ft).

Visit the Borderland Mk II web page

Versatile frequency response adjustment

Further bass adjustment may be obtained by rotating the loudspeaker around the axis of the DDD driver array to change how the bass radiation interacts with the room. You can also switch the left and right cabinets over. This can give quite a large adjustment. We have only ever had to use this at audio shows to deal with the occasional really difficult room.

Emperor DSP-X digital crossover

The active version of the PQS-302 is supplied with our Emperor DSP-X digital crossover. This allows the loudspeaker to be bi-amped. This provides a number of advantages:

• The overall frequency balance may be changed by adjusting the relative balance of the crossover’s woofer and DDD driver outputs. This may quickly be done using the front panel level control.

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• Because the power amplifiers are connected directly to the drivers, damping of the driver movement is increased and better control is achieved.

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• Elimination of the passive crossover eliminates power dissipating elements in the crossover, increasing efficiency.

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• Elimination of the components in the passive crossover whose value might change as they heat up, gives a more stable crossover characteristic.

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• More precise adjustment of the crossover’s characteristic may be achieved using a remote control Ap that works with Windows, OSX and iOS devices. It allows the user to set up to 8 filters where they have the choice of the filter type (bell, shelf, notch, or all-pass), centre or turnover frequency, Q or bandwidth and gain. These settings can be saved in user set-up memories and recalled as required.

Visit the Emperor DSP-X digital crossover web page

Easy to assemble
and set up

Something not often thought about when the potential customer is contemplating purchasing a larger loudspeaker is how is the dealer going to get it into their house. The PQS-302 weighs 115kg (232lbs), which while not in the monster class, is still a lot to move in one piece, especially when access to the room is not easy and you don’t have a lot of people to help. We have struggled up more than enough rickety stairs in the dark with large heavy boxes to to take this very seriously. The PQS-302 breaks down into a number of small modules that fit together without the use of screws and it can be easily assembled by two people. Breaking the loudspeaker in smaller modules makes it easier to ship and reduces the chance of it being damaged en route.