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I-audio - Volume 3 No.1 - 2003 - Singapore

Dueveling


at the moon

Imagine a horn loudspeaker in your living room with a mouth the size of a barn door. Imagine a pair of them. Now imagine a home theatre setup with them inside your home.
Daunting isn't it? It would arguably be the best setup that money can buy but who can afford the space? Fortunately, Duevel is not in the business of monstrous horns. What they do produce is one of the most innovative loudspeaker designs that use really classic technology with new ideas.

Duevel loudspeakers are hybrids. They use a horn for the high frequency compression driver and a high compliance woofer for the bass-midrange. The woofer is loaded in a very unusual enclosure. Not only does the woofer fire upwards but the enclosure has got triangular slots at its four corners. And the loading of the woofer is not your usual bass reflex. Precise calculations were needed in order to calculate the optimum frequency for the Helmholtz resonator configured ports. That is why four tunnels exit via the four openings from the main chamber. Each is tuned precisely to fully optimise the woofer's output. To maintain sonic purity with the fast sounding compression driver, the woofer's 220mm diaphragm is made out of carbon fibre. Furthermore, the surround is of a double corrugated type belying its proaudio leanings. This, together with the carbon fibre woofer will definitely keep the lower regions up to par with the compression driver's output.

    Now for the clinker; this is not your usual loudspeaker. Yes, it has a horn to cover the higher regions. No big deal, you say. And the woofer is in a bass-reflex-type box. Again, no big deal. But if you were to see it yourself, it sure does not look conventional. The compression driver is located on top of the speaker firing downwards with the woofer firing upwards! And there is something in between the two that isolates as well as combines the output from each driver. It is a dual lens to allow sound to spread around the loudspeaker. Yes, Duevels are omnidirectional speakers allowing them to be placed away from walls. What the lens does is to prevent the horn loaded compression driver from beaming high frequencies, which can be irritating at high SPLs. Also the lens spread it out in a 360-degree arc. For the woofer it also spreads the dispersion in a 360-degree area and at the same time couples the output from both drivers seamlessly. The rounded edge of the lens does this nicely with minimal diffraction effects. Therefore the lens produces a point source that is constant as well as non-directivity throughout the room reinforced by the bass ports at the base of the speakers. What you get is a very big sweet spot, a pretty fast (almost horn-like) sonic signature and a very attractive and slim floorstanding cabinet.

    I tried tracks tracks ranging from vocals to New Age. The sound was definitely unusual for this is my first experience with this type of loudspeaker. It was definitely holographic in quality. Playing female voices from Rob Wasserman "Duets" album brought the Bella Luna's imaging qualities to the fore. It is rare combination of definition and realism with 3-D imaging, a domain which so far only electrostatics excel in! Voices where sweet and beguiling especially Jennifer Warnes and Rickie Lee Jones. Every nuance and inflection, when saliva was swallowed, when the mike was too close to the lips, inhalation before belting out a note, I could go on. Exquisite.

    There was a bit of boxy colouration evident but it was a good thing as it gave some 'body' to the guitars and bass. Hey, we're used to this kind of colouration anyway so it is good. The space surrounding each performer was also excellently portrayed. A good track to test whether your speaker has too much latent energy is Big Joe Mahler's 'Mojo' track 9. It is a duet between Mahler and an upright piano. It is not the recognition of the latter that I was trying to highlight but the way the speakers reproduced the pianist's control over the keys and decay of each note. You can actually hear when he wanted to extend a note and when he wanted to stop it abruptly via the foot pedals. This is rare.

    One more complex tracks like Strunz and Farath's 'Heart of the sun' album, the Bella Lunas spread the music out in a wondrously broad soundstage. Layering is not usually possible in lesser speakers but with the Bella Lunas, it was amazing! This trait was also evident on Brandford Marsalis' 'Trio Jeepy'. Especially when he walked around the room to go from one mike on the right to share with one on the left with the bassist. What a combination!

    Okay, even speakers have drawbacks. If you love listening to bass heavy music, they are not for you, although the manufacturer states a 40 to 20kHz frequency spread. Low bass is evident but not as meaty as most bassheads would consider kosher. It was a bit on the lean side, thanks to the careful design of the Helmholtz resonating ports. In fact, it was a bit horn-like in character; fast, lean but went a lot deeper than horn speakers this size. I guess a compromised had to be reached since the bass had better match the performance of already fast compression driver. The Bella Lunas need a sizable room to breathe; you normal puny HDB bedroom will not do them justice. The hall would be more appropriate. Also, you need a real macho amp to drive these speakers. Not because it has a crippling impedance load; it doesn't! It is because the output is so smooth with hardly a hint of compression at high SPLs, you just want to play music louder! But it also depends on the type of music that you listen to. The Bella Luna's highish 91dB/6Ohm sensitivity would be a nice companion to a 8 Watt single-ended amp too. Finally, the price, if you find the price tag to daunting, there is the Venus, at about half the price. Same design but different sensitivity, woofer size and materials.

    I would dare say that the Bella Lunas come very close in offering what both an electrostatic and horn loudspeakers can both do but separately. High transparency with 3-D imaging coupled with an unimposing size, you're practically baking your own cake and eating it! Anybody wanting to play with either horns or electrostatics without the imposing size of the former and humidity affecting the latters's diaphragm, Duevel offers the best of both worlds with the penalties.

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