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The evolution of the first working pair continued: "The V grooves on the corners of the omni mid array are filled with permanently elastic sealing compound. When it sets, its state resembles old dry chewing gum which is great for damping the wall vibrations while being hard enough to add strength. The thing sounds completely different now when you knock on it. Very woody and dull. Still, that will be further 'destroyed' by adding a lot of rubberized cork."
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![](raal3_1.jpg) |
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![](raal3_2.jpg) |
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We'll now segue directly into images of the first operational pair which, right after our visit, would get disassembled again to trim out the still missing cosmetic bits that the demonstrator pair for the Denver show was expected to show.
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Voilà, the descent into Cap'n Nemo's Nautilus - er, Raal's dedicated listening room where the omnis sat on a raised bed of concrete, sand and stone.
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![](raal3_3.jpg) |
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This pair had gone live just a few hours prior to our arrival. Various crossover parts still sat between the speakers and music server PC, with additional coils for the bass system delivered later which Alex then substituted.
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![](raal3_4.jpg) |
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At first, the heavy curtains behind the speakers covered the entire wall. Their absorptive effects killed off some rear-firing mid/treble energies and therewith, much of what an omnipolar speaker adds to the sonic picture over direct radiators. In other words, this particular room treatment proved counter productive. Once Alex had opened the curtains and tied them together in the middle, we moved the speakers towards the listeners a bit to increase the front wall distance and delay time. The next step was to sync up some absorptive sidewall panel placements and presto, the acoustic energy leapt into the room to engage our small audience.
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![](raal3_5.jpg) |
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The Chinese-sourced aluminum cone midranges sport a newly developed ceramic-based damping compound on their skins and a large 1-inch voice coil mated to a Neodymium motor. The Spanish Beyma woofers proved surprisingly low-mass for their size and a shot up the open 6th hole of the bronze bass sphere showed just how tightly Alex has clustered his bass weaponry. In fact, the surface area of the bronze is rather smaller than the radiating surface of the woofers.
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![](raal3_6.jpg) |
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The next shot shows the copper foil connections and amorphous-core transformer for the tweeter array which the finalized speaker will hide together with the crossover assembly beneath a cylindrical head cover above the ribbons.
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![](raal3_7.jpg) |
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As do the OEM ribbons, the Raal-exclusive omni ribbon array to be used only by Alex (i.e. unavailable to other manufacturers) sports the same foam deflectors to control vertical dispersion. The concomitant attenuation of high treble energy is counter-acted by an inbuilt 3dB response lift in the ribbons themselves. This makes the foam an integral part not just of the desired dispersion pattern but also the in-room frequency response.
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![](raal3_8.jpg) |
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An (underlit) close up of one ribbon shows the embossed pattern which breaks up surface standing waves. A friend of Alex's works at Siemens and this connection allowed Alex access to some very advanced test and modeling equipment to measure the phase behavior of his ribbons over their entire bandwidth. Without going into proprietary technical details, I have seen some of the software-driven animation of these tests to feel comfortable stating that Raal ribbons are backed by extensive and very sophisticated real-world engineering. How these ultra performance ribbons are actually built will be shown on the next page.
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![](raal3_9.jpg) |
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Below are some of the bits 'n' bobs of the crossover which Alex naturally was still tweaking. Remember, he himself hadn't heard this speaker until about an hour prior to our arrival. Quite daring, don't you think?
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![](raal3_10.jpg) |
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Now some technical specs. The omnipolar true ribbon sports an aggregate surface area of 315 square centimeters as opposed to your garden-variety 1-inch dome tweeter. The crossover transition from bass sphere to midrange array occurs at 200Hz with a combined 1st/2nd-order lo/hi-pass. An equivalent transition is set at 2500Hz between mids and ribbons. The input impedance of the forthcoming 300-watt 8 x KT88 push/pull amplifier will be 16 ohms, the customer's amp to drive the mid/high array (and input of the included bass amp) sees 4 ohms for the direct connection. Frequency response is 30 - 40,000Hz and anechoic sensitivity is 90dB. Perceived sensitivity in a standard (echoic) room will naturally be higher because it adds the reflected energy. Alex estimates about 94-95dB. Recommended amplifier power is 10 - 500 watts and total dimensions are a surprisingly compact 63 x 63 x 155cm, with the diameter of the mid/hi cluster 20cm or slightly wider than a CD jewel case. The weight of each speaker is a rather manageable 85kg. The external bass amps will be approximately 30kg each.
Alex's patent attorney arrived on the second day of our visit to present Raal with a registered trademark for the cosmetic design of the Eternity and forthcoming 'baby' Instinct model. The latter will use 8-inch woofers and likely an upper array based on a square cross section with fewer drivers.
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![](raal3_11.jpg) |
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![](raal3_13.jpg) |
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Though Alex seemed visibly disappointed, that's the one I'd like to review. While my new sound room in Switzerland has ample of cubic air volume to accommodate the Eternity's prodigious woofer arsenal, I don't have quite the room width which common sense and - um, instinct tell me the flagship speaker really wants to see.
But the sound of the Eternity even in pre-production form with a brand-new unproven crossover, a modified but still conventional class A/B Classé amplifier and bog-standard cabling in a room originally optimized for direct radiators was so promising that I'd be sorely miffed if I wasn't on next year's review list for the Instinct. How's that for public coercion, you think?
Actually, there was some coercion afoot, albeit of the private kind. You see, Alex had built himself a one-up headphone using Raal ribbons. After scissoring out some new foam pads and adjusting the jury-rigged head band for my bigger noggin, I took them for a spin.
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![](raal_instinct.jpg) |
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![](raal3_12.jpg) |
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Bloody hell. Then Alex had the gall to inform me that he'd not go into production until much later in Raal's existence. He didn't believe a statement ribbon-based consumer audio earspeaker from a Serbian company very few had heard of stood a chance in the market place at this time. Since press members never have to worry about selling products nor deal with any of the heart aches that accompany it, I naturally protested. Proof of concept. An entry-point for those financially or otherwise unable or unwilling to purchase a Raal-enabled loudspeaker. I invoked all rational and irrational arguments I could muster. Alex's friends present during our visit sided with the designer. So I dropped the subject.
A few days later, my poison had done its job however. Alex thought that my "proof of concept" argument -- a Raal ribbon used in a headphone which many many more people could sell and buy than bigger, far more expensive commercial loudspeakers by Siltech and Crystal Cable and N.N. Acoustics (and whoever else might join this growing list of manufacturers using Raal) -- was irresistibly persuasive. I promptly offered Alex a review in these pages even should the loaner headphone still be in preproduction form. Should it encounter significant criticisms on performance, wear comfort, appearance or fit 'n' finish; and should he see fit to address any such points before entering formal production; I'd then add a follow-up report on the final version. In very transparent fashion to our readers, this two-punch approach could offer a rare 'behind-the-scenes' glimpse into the R&D cycle of a product, similar to what today's informal report on the development of the first Eternity pair attempts. Alex has already agreed to this plan. Yousa. I for one would be very keen on seeing a superior ribbon headphone. For now, let's take a casual look at how Raal ribbons are made.
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