"For the midrange I wanted a single driver to cover all voices from the lowest bass of a Gregorian chant to the highest coloratura soprano. That meant a driver which could do 65Hz to a least 3.3kHz with minimal directivity. The Supravox well exceeds that with reach to 15kHz. I also wanted a dipole system. My short horizontal TQWT gave me the exact result I dreamt of. For bass I started with Audio Technology and Audio Elegance woofers. I simply wasn't 100% satisfied. Now I commissioned a 15" Supravox woofer for Zero and a 10" Audax for Zero Junior so both projects are still evolving. I'm even working on my M3/M1 tweeter to try it as an open dipole. I'll update you as things firm up." [First proof-of-concept M Zero at right.]
Meeting an ongoing project during its R&D genesis can document design decisions beyond staring at a fully formed final iteration. Whenever I get a rare chance to play fly on the wall, I enjoy learning more about that iterative process. Today we dove into the deep end first without any foreplay. It's because intros were made extensively in our two prior reviews.
The Model Zero is expected to be Aurai's flagship. A flagship carries a fleet's admiral. The M Zero Junior would then carry a captain of long course. That was Alain's actual position in the French merchant navy where he worked as an electromechanical engineer for 22 years.
For the speaker under consideration today, Alain said that "the actual concept is more important than the details of its execution." As mentioned, he did reset himself to zero for the design. An understanding of what informed core decisions is key then. Most of us have heard of band-pass designs only in automotive subwoofers. In the high end, ports rule, sealed and transmission-line bass is rarer, dipole bass even more so.
"There's a lot of money behind automotive sound and many of their systems work better than audiophile jobs. Personally a woofer in a sealed chamber which radiates into a controlled cavity is my favorite solution for serious bass." Combining non-dipole bass with dipole mids and tweeters is unusual. That combination's most famous proponent is probably Carl Marchisotto with first Dahlquist, then Acarian Systems Alón, presently Nola by Accent Speaker Technology. For their dipole sections, Carl's cabinets are laterally open [see above left]. Alain's only open in the back to look like conventional boxes from the sides. As the Nola website reminds us, dipoles eliminate four common problems:
♦ enclosure panel resonances
♦ air column resonances from enclosure-trapped air setting up standing waves
♦ time-delayed resonances of sound being re-transmitted through the driver cones
♦ and driver resonances caused by trapped-air stiffness.
About Alain's many specialized measurements, "they have no interest in emotion. Measurements just help chase down the desired emotional response. Technically I focus on the impulse response and in-phase transients. To call any speaker design complete, I look for emotions and poetry like Matila Ghyka does in her famous book on sacred geometries, The Golden Number. Without love and magic, it's impossible to make a musical reproducer. In fact, I don't design loudspeakers. I try to make instruments capable of reproducing the emotions encoded in the music. I'm a retired man. I need to make no more money. I seek no more glory. I just enjoy life and continue to thrive on engineering challenges."
Notre Dame de la Garde Basilica of Marseilles beneath which we see one of Alain's concepts for a much bigger hornspeaker.
Did you take note of the interesting connection in these quotes, between emotions and a loudspeaker's time-domain behavior?