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The Vivid K1 is the biggest Oval and on its integral molded support stands 1.4m proud. This stand is made from the same cast carbon-fiber reinforced polyester compound as the enclosure itself and inseparable. It provides for very stable footing that can be fine-tuned with five spikes mounted around the periphery of the base. The slim profile of the K1 does not create any potential placement issues in the room but its imposing depth plus rear-firing woofers might. As the roll-off of the rear drivers is set at 90–100Hz, the K1 doesn't require extreme distance from the front wall but its bidirectional port remains a consideration. Small rooms should consider the B1 instead which will impose minimal placement restrictions.
G3 crossover's two sides.
Now don’t think that Dickie’s unusual and audacious engineering limits itself to enclosure design. Crossover filtering also calls for advancements to remain in line with the asking price. The K1 has a double array of C125 mid/bass drivers on the front and rear sides which operate in an unusual manner. Below 100Hz all four woofers are active. Above this the lower front woofer and both rears roll off progressively to have only the upper front unit hand over to the midrange dome at 880Hz. This ensures excellent vertical dispersion at the crossover point.
Laurence Dickie explained that "the C125 drivers above are arranged as a square formation at low frequencies so that the impedance is the same as a single driver. From about 100Hz up the two rear drivers and the lower front driver roll off eventually leaving just the top front driver connected to still offer the impedance of the single driver. We refer to this as a 3½-way system because the lower midband is shared with the bass section. The advantage is that one style of bass/mid driver can be used for the entire band from the lowest frequency right up to the 880Hz crossover point."
4th-order 24dB/octave Linkwitz-Riley filters ensure phase coherence through both main crossover points resulting in a seamless symmetrical polar performance. As the same midrange drivers and tweeters are used in the entire line of Vivid Audio speakers except for the V1, the crossover is basically the same for the Giya range except for the bass array's specific woofers in addition to the mid-bass units. In contrast to the K1 design, the Giya speakers are true four-way systems whose side-firing woofers are limited to sub-220Hz frequencies. This optimizes each driver more for its specific bandwidth. Laurence Dickie calls his kind of crossover a series/parallel square because it maintains linear impedance across the band. The crossover is exactly matched to the drivers' acoustic roll-off.
The four mid/bass units couple internally as pairs via screw tensioners for reaction canceling. This coupling ensures that enclosure reactions from the front-firing drivers are canceled by their rear-firing mates. The K1 xover sits in the relatively flat base and is made of two sides, one for the low mids and the other for the mid/high frequencies. Each filter part terminates in its own binding posts for separate grounds and efficient biwiring or biamping. This filter architecture is shared by all models except for the small Oval V1.
More obvious than the filters are the proprietary drivers. Once again Laurence Dickie's approach is unusual. Consider the use of the same mid and treble units called D50 and D26 across all models from the B1 to the most expensive G1. These two anodized aluminum domes are not hemispherical but rotated catenary in shape which is said to push the first break-up mode 50% higher than regular aluminum domes would. This shape is a further optimization of what was initially and partially achieved with a carbon-fiber ring affixed to the edge of each dome driver to move the first break-up mode almost an octave higher than more common spherical aluminum drivers. Anodized aluminum alloy according to Dickie represents the best combination of stiffness and density over titanium and magnesium. Compared to other more exotic materials the optimum price/performance factor favors aluminum again. And very expensive materials like diamond or beryllium become less attractive when a company like Vivid designs and builds its very own drivers from the ground up.
All their diaphragms are optimized by computer-aided finite element analysis for the highest possible first break-up modes. In the case of the mid/bass C125 this yielded an unusually shaped central dome which isn't as much a dust cap as an integral structural element. The C125 divides into a steeper inner and shallower outer zone. The cap attaches at the transition point. Dickie considers the cap's shape the optimum for a homogeneous dome without any peripheral stiffening.
The preference for exclusively pistonic drivers across the audible bandwidth came from Dickie's many experiments with cone drivers which showed him how cone breakup is always audible and always results in undesirable colorations. His B&W Nautilus legacy introduced tapered tubes behind mid and treble domes within the cabinet, their ends covered on the rear. By designing his domes with external ring magnets, their rear radiation is damped and absorbed by the tapered tubes which behave much the same way as uniform diameters would but now can be considerably shorter especially with added fiber fill.
