New Array Loudspeakers From Nexo

Nexo has just introduced GEO S805 and S830 loudspeakers, both compact full-range loudspeakers that can be combined in horizontal or vertical arrays. They can be accompanied by new CD12 subwoofers that also integrate within a GEO array structure.

The company recommends GEO arrays for applications where sound pressure levels must be tightly consistent over distance, including stadiums, arenas, convention centers, airports and other transport terminals, and for musical and theatrical shows. Both models include an 8-in hi-flux neodymium cone transducer that reproduces frequencies to 60 Hz and a 1-in neodymium compression driver, loaded on a patented wavesource, extending frequency response to 20 kHz. The S805 has a 5-degrees HRW (Hyperboloid Reflective Wavesource) in the coupling plane, and the S830 has a 30-degrees HRW in the coupling plane. Both the S805 and S830 incorporate the DPD (Directivity Phase Device) on their 8-in woofers, and the CDD (Configurable Directivity Device), which allows the user to change dispersion in the non-coupling plane from 120 degrees to 80 degrees. (More on HRW, DPD and CDD below.) The HRW has a virtual source behind the cabinet, allowing multiple GEO loudspeakers to couple with no acoustic interference and behaving more like a single source. Consistent front-to-rear SPL, improved coherency, efficient zone separation and minimal reverberation from reflective surfaces are some of the major performance advantages of the new system.

The S-805 makes it easy to assemble precisely shaded curved vertical arrays with SPL that can decreases from -3dB to -6dB per doubling distance over the entire audio frequency range. System designers control the curvature shading of a coherent, isobaric line by setting the angles between the cabinets when designing the array:

NEXO software predicts the results for a variety of line lengths, curvature angles and audience slopes. A S-830 can be rigged below a curved vertical array of GEO S-805 for near-fill coverage.

S-805 and S-830 are totally complementary and both can be used in horizontal or vertical arrays. And, a GEO S-805 can be arrayed next to a GEO S-830 for long-throw coverage in horizontal arrays.

GEO Series loudspeakers are processed with the NEXO NX241 TD Controller, which includes GEO presets.

The cabinets have the same overall dimension as the NEXO PS-8: 25cm (W) x 40.6cm (H) x 21.9cm (D). A precision array assembly system supports curved vertical arrays of up to 16 cabinets, with control of cabinet splay in 0.5-degree increments. Bumpers and connecting accessories are part of the array assembly system.

GEO S-805 and S-830 are expected to be shipping at the start of 2002.

This new technology incorporates three fundamental patents:

- The Hyperboloid Reflective Wavesource controls the spherical expansion of the acoustic pressure wave using an acoustic mirror instead of coercive side walls. The HRW is more accurate than conventional waveguides, and multiple HRWs can be combined without interference or loss of coherency since the hyperboloid acoustic mirror has a virtual source behind the speaker enclosure, as well as a real source inside the enclosure.

- The Directivity Phase Device or DPD enables multiple woofers to couple effectively at higher frequencies than would be possible with simple direct radiating cones.

- The CDD Configurable Directivity Device alters the dispersion of a diffraction slot: GEO wavesources use a diffraction slot and exponential flare to control dispersion in the non-coupling plane.