We thought we would look back to when omnidirectional loudspeakers first appeared and specifically to designs that used a conventional driver firing into a diffuser to produce the omnidirectional sound field. This is not a comprehensive catalogue of this type of loudspeaker, rather the highlights of some very notable and forward thinking designs, considering the time period they were conceived. 

I have always been a fan of single driver and horn-loaded systems. The “eureka” moment came when I was introduced to the German Physiks Unicorn, a single driver, horn-loaded, omnidirectional speaker. I was curious on what was driving the excitement amongst the Japanese audiophiles to put the Unicorn in their living rooms, especially given its unconventional engineering and looks. After living with it for 15 years, I never looked back. It has been my go-to speaker for jazz, blues, vocals, and chamber music. The one speaker I will never part with.

It is very immediate, open and natural sounding speaker without any of the negatives of the multi driver speakers. Lack of crossover is obvious in the music material reproduction without any discontinuity or breaking-up across the entire frequency spectrum.

Borderland Mk I was the first German Physiks loudspeaker. It used a titanium DDD driver and it covered 270Hz to 19kHz. The bass was taken down to 28Hz by two 20cm woofers operated in an isobaric arrangement that vented through a circumferential grill near the top of the cabinet. 

The need for an entry model below the Borderland prompted the launch of the Windspeil [wind chime, shown left]. This used the titanium DDD driver as the Borderland Mk I, covering 140Hz to 19kHz. The bass was handled by a 20 cm woofer mounted on the front of the cabinet driving a vented enclosure, with the port also on the front of the cabinet. 

This talks about the Walsh omnidirectional driver, which was used in the Ohm F loudspeaker and was the inspiration for the DDD driver. 

It explains how the German engineer Peter Dicks was inspired by Lincoln Walsh’s brilliant Walsh omnidirectional driver, to design the DDD driver and how was incorporated on all German Physiks loudspeakers. It also explains the important improvements of the DDD driver over the Walsh design.

Left: Ohm F loudspeaker

Audiophiles and reviewers alike have often talked about the DDD driver’s very wide frequency response in achieving a high level of sound quality. But so far we have not explored enough an equally important property of the DDD driver, namely its excellent phase linearity.

In this section we thought we would share with you a bit more about the three larger models produced by German Physiks, the PQS-302, PQS-402 and Loreley Mk III. They all share a common modular design. PQS stands for Premium Quality Speaker and represent the elite of German Physiks innovative design and life like performance. These models came about from the need to provide higher sound levels and drive larger rooms than was possible with the single DDD driver models. 

“Built to very high standards and offering an impressive array of sonic attributes that will satisfy both the ardent audiophile and the music lover, the Borderland’s unique styling and omnidirectional sound place this German delight on the must-audition pedestal. Remember during your audition that, like a fine Riesling or Schnapps, with time your appreciation of the Borderland’s unique attributes will grow.“

This is a story on how a request for a pair of replacement DDD drivers for a used pair of speakers from Japan led to the formation of the German Physiks appreciation society there. It all started in June 2012 when GP was contacted by a customer in Japan who had bought a used pair of Unicorn Mk Is.  They were 14 years old at the time and long out of production.  It used the titanium diaphragm DDD driver to cover the entire range from 21,500Hz to 55Hz.  In all other German Physiks loudspeakers, the DDD driver is rolled off at around 200Hz and the bass is handled by one or more conventional woofers. A very moving story unfolded. Read all about it below.