Nexo’s new GEO T Tangent Array System for large venues and outdoor applications will be shown for the first time at the Musikmesse in Frankfurt, and makes its American trade show debut at the NSCA expo in Dallas.
The GEO T Series expands on the experience gained from the development, testing and successful operation of Nexo’s first tangent array design, the GEO S. Since the product’s launch in 2001, the worldwide user base of GEO S systems has grown dramatically, and it has rapidly become one of the leading compact arrayable loudspeakers in both portable sound and fixed installation markets: the recent contract awarded ZAP Audio for the installation of GEO S830 horizontal tangent array clusters in Geneva Stadium is an example.
The T4805 and T2820 are the new full-range high-output loudspeakers at the heart of the GEO T Series, together with a new Controlled Directivity Subbass, the CD18. GEO T has been engineered as a scalable system that can handle audiences from 1000 up to 100,000 or more. Developed in conjunction with leading touring sound rental companies, GEO T has been successfully field tested by SSE Hire (with Tori Amos) and by Show Company in Singapore (with Alan Tam).
Patent-pending features of GEO Technology proven in the GEO S Series can be found in the new GEO T system, including:
- The revolutionary Hyperboloid Reflective Wavesource (HRW) uses an acoustical reflector derived through rigorous mathematical transformations. It has a real source (the compression driver) and a virtual source which can be located outside the enclosure. The virtual source can be made coincident with or tangent to another HRW, producing coherent coupling between multiple speakers, even when they have different dispersion angles. The coupling plane can be either horizontal or vertical, making GEO array modules suitable for both curved vertical arrays that deliver equal power to equal areas, or for horizontal arrays that deliver equal power to equal angles. Patent pending.
- The Directivity/Phase Device optimizes line source coupling between cone woofers in vertical tangent arrays. Long-throw 8 inch cones can handle low and mid frequencies with ease, but their acoustic centers are too far apart to couple as a line source at the crossover to the compression driver. The DPD divides the cone in two. This creates the equivalent of a closely spaced line of smaller drivers that couple as a line source at crossover, without compromising the low frequency output of the 8 inch driver. Patent pending.
- The CDD Configurable Directivity Device lets the user select the dispersion. GEO wavesources use a diffraction slot and exponential flare to control dispersion in the non-coupling plane. Patent pending.
GEO T COMPONENTS:
The GEO T4805 Vertical Tangent Array Module
Featuring a 2″ exit compression driver (HF), two front-firing 8″ long excursion neodymium cone drivers (MF/LF), and an additional pair of rear-firing 8″ long excursion neodymium cone drivers (LF only), the T4805 extends NEXO’s unique Controlled Directivity LF to the midbass region. The T4805 has a 5° HRW which allows variable curvature in a vertical coupling plane, adjustable in logarithmic steps from 0.125° to 5° with 0.01° precision. The system makes highly efficient use of amplifier power, with minimal cabling losses due to 32 Ohm impedance.
User Benefit: the GEO T4805 is a 3-way device which provides cardioid midbass using four long excursion high output neodymium 8″ cone drivers. Cardioid midbass improves control of long wavelengths in both the horizontal and vertical planes and allows shorter arrays to project low frequency energy as effectively as the higher frequencies. With Nexo’s NX241 digital controller generating a 90° x 90° cardioid pattern from 70 to 250 Hz, the T Series can control low frequencies with shorter lines than array modules based on horizontally spaced pairs of large-diaphragm cones.
The GEO T2820 Vertical/Horizontal Tangent Array Module
Featuring a 2” exit compression driver (HF) and two 8” long excursion neodymium cone drivers (MF). The T2820 has a HRW with a 20° curvature in a vertical or horizontal coupling plane, adjustable from 8° to 20°. The GEO T2820’s CDD™ (Configurable Directivity Device™) provides 120° dispersion in the non-coupling plane, enhancing its effectiveness as a downfill element in curved vertical tangent arrays.
User Benefit: The GEO HRW is the only dispersion control device that allows the array designer to vary the curvature of vertical arrays in inverse proportion to distance without compromising coherent coupling. This allows the imaging and definition to be as clear in the front rows as at the rear of the audience area.
The CD18 Subbass
The CD12 developed for the GEO S Series introduced NEXO’s unique Controlled Directivity Subbass. The new CD18 extends cardioid directional control to 31.5 Hz, thanks to its dual 18 inch woofers and the DSP algorithms of the Nexo NX241 digital controller. CD18s can be flown or stacked.
GEO T Flying Hardware
The GEO T system is very compact and lightweight compared to other high output line arrays. Designed from the start to be safe and easy to fly, the system incorporates Vertical Tangent Array top and bottom bumpers, which allow adjustment of the tilt angle and curvature of vertical tangent arrays using a two-motor chain hoist system. All GEO T hardware is designed and tested to maintain high load safety factors in curved vertical arrays, which introduce very high stress factors due to the change in angle from the vertical.
GEOSoft Array Design Software
GEOSoft is not just a simple spreadsheet of “aiming angles,” but a compiled MatLab application for the design of curved vertical arrays. This provides a fast user interface to the modeling software used by NEXO R&D in product development. Predictions have been verified by field measurements.
