April
2022

Divine Acoustics Bellatrix

Divine. In the Tara Labs Zero, we had the cable God listens to; at least according to designer Matthew Bond who is on his 3rd company since. Doing business with God seems to pay.

What about the rest of the heavenly hifi? We've not heard much about it.

If we ask Piotr Galkowski of Ozimek in Opole County of Poland, he might suggest a pair of Bellatrix with his Halley ribbon speaker cables. When the Pope can be Polish, why not God's loudspeaker?

With that settled, onto earthly specs. This 120cm tall  2.5-way tower with a 25mm soft dome from Scan Speak's Illuminator range plus from Germany twin 7" Eton embossed paper mid/woofers from their Orchestra series (the lower one enters on a 1st-order at 250Hz, the upper one meets the dome on a 1st-order at 2'900Hz) uses a very complex octagonal cabinet and 51-part filter behind an acrylic spy glass with carbon-fiber trim walls. Window shoppers see copper Miflex and Jantzen aluminum, Z-Superior and Z-Standard caps, metallized non-inductive resistors and cotton-wrapped OFC inductors.

Even the included Kepler footers go extra miles by handling up to 20kg each whilst containing 40 elements across 7 dissimilar layers. Inside is a rectangular ceramic bar coupled to gemstones arranged in a pyramid shape. Its stones are kept in a fixed position to load chromium-nickel steel for a 3-layer system. The pyramid rests on the ceramic bar surrounded by elements that gently compress the system. A threaded spindle transmits vibrations from component or loudspeaker to the top of the pyramid. Steel, chromium, nickel, copper, titanium, molybdenum and auxiliary elements of wood and polyamide are also part of each Kepler. To use under components or other speakers, a set of three sells for €350, a quartet gets €450. If that's how elaborate the footers and filter get, just what goes inside the cab? It's no even-sided octagon. It leans back. It steeply slopes up on top. It flaunts a narrow spine and mixed surface treatments. To show off how well it braces internally and subdivides into chambers without any loose fill but creates a hybrid of a quarter-wave tapered line with large downfire port, Piotr dedicated a whole page to the "Making of". I suggest you read it now to also learn about single-point grounding, decoupled driver mounting, hand-made copper hookup wiring and more. Even the outer binding posts are Piotr's own design. One comes away thinking that he's an extremist of the first order. He rolls off very gradual if at all. He even trims the leads of all filter parts down to the matched millimeter. That's proper obsessive.

It all adds up to an 88dB/4Ω load of 29kg recommended for 16-40m² listening dens. To fully form the many filter capacitors, we read about 500 hours. Available finishes are mocca and smoke. Snakewood as the right unit of the trio above is limited to just 10 pairs so possibly sold out by the time you read this. Divine Acoustics. A bit of perhaps sonus Faber in the overall shape meets Wilson for the peekaboo xover meets Polish ingenuity. She's called Bellatrix like the 3rd-brightest star in the Orion constellation; or to get less celestial, the character Lestrange of the Harry Potter books as played in the movies by Helena Bonham Carter: "My Lord, I'd like to volunteer for this task."

What the witch said; about this assignment.

Tweeter mount subassembly for strategic vibration isolation.

The Dark Art of speaker design. Even without magic wand, we appreciate that selection of parts, tuning of their interactions and finally, anticipated embedding in all manner of rooms—the details of which the designer can't know—is no straightforward computer simulation. But basic math still tells us that from the lower midrange down, Bellatrix is a 10" two-way. That's because two 7" drivers add up to one compound driver of 9.9" Ø. Halving duty to meet the 2'900Hz tweeter with one driver shrinks the 10-incher back to 7". In the higher freqs, a smaller driver has advantages. That have-your-cake-and-eat-it solution is also favored by Michael Børresen of Audio Group Denmark. Why not a 3-way instead? A 2.5-way's midrange driver only sees a low-pass below the tweeter. There's no high-pass above any woofer. In the bottom it runs wide open like any 2-way. And having two bass drivers share the job of one works them less hard so excursions diminish, distortion lowers.

Premium drivers are only the start.

Piotr's selection of tweeter was predicated upon matching its sensitivity to that of his chosen 4Ω mid/woofer without voltage divider or padding resistor. Why mate a 99dB tweeter to an 88dB mid/woofer only to suffocate the tweeter by 11dB? As to the C-19 lockdown, Piotr turned lemons into lemonade. He extended his R&D cycle to a full 4 years to perfect every detail to the nth degree: the tricky bits of Bellatrix.

Even casual bystanders will appreciate that this Divine Acoustics speaker isn't just another rectangular box with an exotic badge stuck to it. If the devil is in the details, what do we think God wants?

The drawing shows the big port tube starting below the woofer.

Here Piotr's workshop shows the skeleton of the Bellatrix cab. We see just how sizable the port diameter in the bottom plate is to suggest good dynamic responsiveness.

Blue metal jig at left for precise alignment of the internal braces and rod tensioners.

The next photo shows what for this octagonal cross section becomes the sidewall treatment. It offsets the veneer skins of the surrounding facets. This clearly is no easy build. Adding up the pictorial evidence, the €9K/pr tag seems unexpectedly friendly. Perhaps crass capitalism hasn't yet breached this country's South West? There's an award already for Bellatrix's first review. Its writer captured the same point with "looking at how these are built, it's hard for me to understand how the company will make any money." That's relative not to direct sales but dealers and distributors. Duisburg's Len Hifi for example who loaned me their demonstrator Linnenberg Georg Friedrich Händel monos bring Divine Acoustics to Germany.

Bellatrix plays backpacker so the loudest part of the room (inside the speaker) doesn't see the microphonic filter components.

Usually here this story would transform into a review. Given current parts shortages which have Piotr back-ordered on his drivers, that's provisionally postponed until he can resume production. If this whetted your appetite for more, have some sparkling water and salad. The main dish is still in the kitchen…