The Frankfurt MusikMesse will be the venue for NEXO’s new GEO system to receive its European debut, with the GEO S805 and S830, the first loudspeakers to incorporate NEXO’s patented GEO technology, and the innovative CD12 Supercardioid Subwoofer on display.
GEO has been added to the NEXO range of products to enable the construction of multi-speaker arrays that are as coherent as single acoustic sources. GEO arrays are particularly suited for applications where SPL levels must be tightly consistent over distance: stadia, exhibition centres, airports and transport termini, as well as musical and theatrical shows. Although they are the smallest and lightest vertical arrays available today, GEO arrays deliver homogeneous SPL levels throughout the audience area and high intelligibility, eliminating the need for delayed speakers in many applications.
The S805 and S830 are compact, high output full range loudspeakers that can be combined in horizontal or curved vertical arrays. The 8” hi-flux neodymium cone transducer reproduces frequencies to 60 Hz while the 1” neodymium compression driver, loaded with a patented GEO wavesource, is flat to 20 kHz. The S805 has a 5 degree HRW (Hyperboloid Reflective Wavesource) in the coupling plane, the S830 has a 30 degree HRW in the coupling plane.
Both the S805 and S830 incorporate the DPD (Directivity Phase Device) on their 8-inch woofers, and the CDD (Configurable Directivity Device) which allows the user to change dispersion in the non-coupling plane from 120 degree to 80 degree.
The S805, S830 and CD12 are compact, high-performance, completely coherent array elements. The HRW has a virtual source behind the cabinet, allowing multiple GEO loudspeakers to couple with no acoustic interference and behave 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 GEO 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 accurately predicts the results for a variety of line lengths, curvature angles and audience slopes. A GEO S-830 can be rigged below a curved vertical array of GEO S-805 for near-fill coverage.
GEO S-805 and S-830 are totally complementary and both can be used in horizontal or vertical arrays.
Processing, Size and Weight
GEO S-8 Series speakers are processed with the NEXO NX241 TD Controller, which includes GEO presets.
GEO cabinets have the same overall dimension as the NEXO PS-8: 25cm W x 40.6cm H x 21.9cm D. GEO S-805 is a trapezoidal shape 5 degree weighing 11 kg, GEO S-830 is a trapezoidal shape 30 degree weighing 11 kg (net of the array assembly system).
Array assembly and suspension
GEO’s 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.
Patented technology, rapid development
GEO technology was developed and patented by Eric Vincenot and Francois Deffarges, designers of the Alpha system, during a three year R&D effort using extensive computer modelling. The match between mathematical models and initial prototypes was so precise that the first loudspeakers to incorporate GEO’s three new patented innovations have been brought to market in just two years. GEO S-805 and S-830 are expected to be shipping at the start of 2002.
This innovative 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.