To start at the proper beginning, there's the 20cm cellulose pulp driver with its secret inclusions. Those added ingredients in the paper recipe eliminate the need for subsequent surface treatments which Galm and Gerhard say can overdamp micro detail. The driver's moving mass is a low 10 grams, "1/5th to 1/10th of equivalent woofers" to act dynamically very aspirated. Its whizzer cone surrounds a wooden phase plug. The magnet is Alnico, the motor's pole cap encased in copper to avoid rising inductivity with frequency which extends the HF response. This twin-cone driver loads into a 44-liter bass reflex box with a QB3 tuning at 55Hz. Its front and rear baffles borrow from BBC convention—think Harbeth and Spendor today—by not being glued but screwed to the carcass using intermediary rubber bands for decoupling. The four-layer construction of 18mm Ply, heavy foil, damping layer and coconut mat is said to increase rigidity and reduce acoustic leakage over the BBC's traditional two layers.


The box is otherwise unbraced to avoid upshifted resonance modes. The voicing deliberately includes remaining box talk as a "quasi additional membrane in the lower midrange". The rear-firing port faces the driver's back to decompress it and raise overall efficiency. Interior surfaces are lined with a roll of coconut fiber and polyester. Three Mundorf parts become response correction filter by linearizing Ω to maximize sensitivity. Final response is given as 40Hz to 25kHz -3dB. Linearity is a promised ±2dB from 50Hz to 15kHz. Nominal impedance is 8Ω, power handling is 50 watts, 2.85V/1W sensitivity is 95dB. The 59 x 34 x 31.4cm box is available in Macassar, Oak, Zebrano or Walnut with high-gloss black front and rear. The grill is either anthracite or beige. Stands from BFly Audio co-designed with Joachim are available in a variety of materials and designs. Cynics insisting that in his graying years Joachim must have gone soft pursuing a purist widebander whose driver development he was personally involved in will take note of his current Tangram model below.



It's in the same catalogue as the Puls (the English word pulse looks rather better to the eye than the German which is just one letter off from the ugly 'puss'). So the Tangram tells us something else. Gerhard is fluent in various speaker design tongues to consider them equally valid and viable. With my soundkaos Wave 40 on hand, I was in a unique position to compare and comment on two widebander concepts that used the same driver platform but then executed their various details quite differently. This fact clearly wasn't lost on Joachim. His gentle pokes at not needing additional tweeters like my soundkaos opted for—not only for better HF but to cut out the Enviee where it gets ragged— said as much.

Whilst at pokes, look at that Tangram tweeter. It's a Serbian Raal ribbon. Exactly as I have in my Swiss eggs. Clearly my meeting with the boxy Puls was preordained. Not that I needed omens. Pure curiosity was plenty sufficient. And though I had no clue about what happened at Audio Physic and Sonics to see their founder leave both, I looked forward to doing my bit to help put the man back on the map under his latest brand. After all, he's quite the legend. Whatever he'd have to say on the widebander subject was bound to be very enlightening.


Whilst awaiting the loaners, I did some online recon. Joachim Gerhard's setup method first publicized for Audio Physic deserved a revisit since it's backed by scientific research from Bernd Theiss and Professor Malkolm Hawsford from the Essex University. Here are some excerpts from Gerhard's paper. "Our approach is examining how room and speaker interact to create the best situation without requiring radical changes to the room. We limit the interference of the room through specific-speaker placement and listening position utilizing the effects of psychoacoustics and physics.


"First, let's consider how we hear. To locate where a sound comes from, our brain senses the time between a sound arriving at one ear, then the other. That's called interaural time difference (IAD). If there's no difference in arrival times, our brain determines that the sound emanates directly in front of us. If the sound reaches the right ear first, the brain determines that the sound is to the right and so forth. Sound placement is determined by the delay time. This determination is made subconsciously and within the first 800μs of the initial transient as that's the maximum possible time delay due to the distance between our ears.
Joachim's home lab shown with Kalasan prototypes of an SB Acoustics Satori driver project.

 
"After this initial recognition of location, the perception of tonality starts. First we locate the sound's source which could be a potential danger. Then we try to identify what produced the sound. Consequently the first step to achieving a good stereo soundstage is to have the direct sound from your speakers arrive at your ears before any reflection of that sound. If the first transient from the primary source arrives sooner than any reflections, it prevents confusion as to where the sound came from... If the speakers measure flat under anechoic conditions, the brain will perceive a flat response when the first transient arrives before any reflections. Even if measurements taken at the listening position show severe deviations in frequency response from reflections, the brain will ignore it and perceive a flat response. Because of this, one goal of our speaker setup is to eliminate the earliest reflections from the walls or windows for example.


"An idealized example of these principles would be a well-proportioned listening room where the speakers are positioned at the two centre points of an ellipsoid touching the walls of the room as shown above. The best listening position is centred between the speakers, your head 1-3' from the rear wall. In this location the sound from the speakers reaches the ears before any reflections from the side walls. The advantages are maximum possible speaker separation for the widest desirable soundstage; and maximum first-reflection delay."