PRODUCTS : LOUDSPEAKERS : The PQS 302

THE 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.


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, whilst also producing a well controlled and balanced response down to 26Hz.


The DDD Driver

The DDD driver is used on all German Physiks loudspeakers and the same quality of driver is used on all models from our entry level product to the top of the range Gaudi. This revolutionary driver gives the same very important advantages to all German Physiks designs and is what sets them apart from our competitors.


The DDD driver’s very low moving mass enables it to operate linearly over an extremely wide frequency range. The PQS 302 uses two DDD drivers mounted one above the other and these cover the entire frequency range from 170Hz upwards. In a conventional design, this range would be covered by two or even three different types of driver and most importantly there would be a cross over pointin the mid-range, the area where our hearing is most sensitive. The DDD driver’s wide operating range allows this vital region to be kept free from the level and phase anomalies that multiple drivers and a necessarily more complex crossover would create. This enables the PQS 302, like all German Physiks loudspeakers, to produce very accurate and realistic stereo images.


Another key advantage of the DDD driver is that it is omni directional, so these excellent stereo images can be enjoyed from a wide range of listening positions, unlike conventional designs, which have much smaller “sweet spots” due to the tendency of their drivers to beam the sound. This makes the PQS 302 family friendly, as several people can enjoy its superb performance at the same time.


The DDD driver’s very low moving mass provides the further benefit of exceptional impulse and phase response characteristics and allows it to reproduce both the attack of the music and provide exceptional low level detail resolution. This is essential in order to faithfully reproduce the delicate nuances and timbral characteristics of a performance and make it sound like music, rather than just good hi-fi. The driver’s excellent impulse response also ensures that the stereo image remains focussed and stable, even when the loudspeaker is reproducing complex passages at high levels.

Low Resonance Cabinet

We have gone to great pains to create a cabinet design that minimises the radiation of sound energy through its panels. The smearing that this would otherwise cause would degrade the loudspeaker’s ability to resolve fine detail, which is essential in order to produce a sense of realism. The PQS 302’s cabinets are constructed from heavy panels of MDF with cross bracing fitted to critical points within the structure. To minimise residual vibration, Hawaphon damping sheets are attached to the inside face of each panel. This 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.


To damp resonances of the air within the cabinet, the whole of the inside of the cabinet is lined with a 1cm thick layer of high density felt. This is achieved by fitting pieces of felt that are precisely cut to fiteach panel, rather than just inserting a roll of felt into the cabinet. Our approach takes longer and costs more, but we believe it produces a superior result.


Versatile Crossover

The crossover provides a wide range of adjustment to allow the PQS 302 to be optimally 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 for the Ultimate Quality

The PQS 302 is available in the customer’s choice of select, hand matched hardwood veneers. These are carefully applied to the MDF panels prior to the construction of the cabinets. This method results in some wastage of material and thus adds to the manufacturing cost, but produces the finest possible furniture grade finish. A multi-layer lacquer coat, hand polished to a high lustre finish, is available as an optional extra.


Special Order Version

A special order version of the PQS 302 is available with a laminated carbon fibre reinforced cabinet. Multiple layers of bi-directional, resin impregnated carbon fibre are applied to the cabinet’s panels using techniques originally developed for the aircraft industry. A multi-layer lacquer is then applied and hand polished to a high lustre. This produces a cabinet that is immensely strong, as well as being practically free from resonances within the audio frequency band. This further increases the already very high level of transparency achieved by the PQS 302. This version is fitted with carbon fibre DDD drivers, which extend the frequency response to 24,000Hz and the maximum output level to 112dB.


The PQS 302 Specifications

  With Titanium DDD Driver With Carbon DDD Driver
     

Impedance

2.9 ohms at 26Hz 2.9 ohms at 26Hz
     

Frequency response

26 - 21,500Hz 26 - 24,000Hz
     
Power handling    
   Nominal
Short term
400W
700W
400W
700W
   
Amplification required 1 power amplifier per channel
Minimum power: 150W/4ohms
   
Crossover frequency 170Hz
   
Crossover slopes  
   DDD section
Woofer section
12dB/octave electronic & 21dB/octave acoustic
18dB/octave electronic & 24dB/octave acoustic
   
High frequency adjustment -2dB, flat, +2dB and +4dB centred at 8,000Hz
   
Low frequency adjustment +10dB, +5dB or flat centred at 58Hz
     
Sensitivity 87.5dB for 1W at 1m 87.7dB for 1W at 1m
   
Maximum output level 110dB 112dB
   
Operating principle 2 way speaker with 360° surround radiation using the DDD Bending Wave Converter
   
Input connectors 2 sets of binding posts allowing bi-amping or bi-wiring
     
Drivers 2 x Titanium DDD drivers
2 x 8 inch woofers
2 x Carbon DDD drivers
2 x 8 inch woofers
   
Dimensions 530mm W x 1,400mm H x 730mm D
20.9" W x 55.1" H x 28.7" D
   
 Weight (depends on model) 115kg // 253lbs 
   
Warranty 5 years