Nexo GEO CD18 Directional Sub-bass

NEXO R&D has used the advanced DSP power of the digital NX242 TDcontroller to develop an extremely compact and highly efficient method for controlling the dispersion of very large acoustical waves.

Nexo GEO S830 Tangent Array Module

The CD18 uses a pair of long excursion neodymium 18" drivers, two amplifier channels and two channels of DSP processing to generate a cardioid or super-cardioid pattern with up to -15dB of attenuation at the rear. Yet, the enclosure is no larger than is required for proper loading of the transducers.

CD18's deliver high-impact subbass energy to the audience while keeping very low frequencies away from open microphones and reflective/reverberant surfaces. The end result is a much more controlled and coherent foundation for the mix, as compared with conventional subwoofers.


  • Unique directional sub-bass with cardioid or supercardioid pattern keeps sub-bass energy away from open microphones
  • 120┬░x 120┬░dispersion, usable output from 29 Hz to 180 Hz
  • Dual-ported 18" woofers fire in opposite directions and are driven in reverse polarity.
  • Requires NX241 Digital TDController and two amplifier channels: each woofer is processed individually
  • Internally braced Baltic Birch cabinet minimises in-band resonances
  • Available in structured black coating or dark grey carpet covering
  • Integrated flying system for use with curvedvertical tangent arrays of GEO T Series modules
  • Cabinets designed for stable gound stacking

Specifications with NX242 TDController

Frequency Response @-3dB[a]: 32 Hz - 80 Hz
Usable Range @-6dB[a]: 29 Hz - 180 Hz
Sensitivity 1W @ 1m[b]: 105dB SPL Nominal
Peak SPL @ 1m[b]: 145dB Peak
Dispersion[c]: Cardioid or supercardioid pattern over the entire useable bandwidth depending on the NX241 Digital TDController set up.(two channels of the NX241 are used for the process)
Directivity: Control is achieved through DSP algorithms in the NX242 Digital TDcontroller (two channels of the NX242 are used for the process)
Directivity Index[c]: Q=4.3, DI=6.3 dB and Q=5.3, DI=7.2 dB over the entire useable bandwidth for respectively cardioid and supercardioid mode
Crossover Frequencies: 80 Hz active through NX241 Digital TDController
Nominal Impedance 2 x 8Ω
Recommended Amplifiers: 2 amplifier channels are required for cardioid operation, each rated at 1500-3000-w into 4Ω per-ch. Up to 2 complete CD18s per channel may be connected to a 2-ch amplifier
Connectors 2 x NL4MP SPEAKON 4 pole (in & through)
Construction: Baltic birch ply finish with structured black coating. Dark grey carpet finish also available
Flying: Integral flying system
Net Weight: 116kg
  • [a] Response Curves and Data: Half-space Anechoic below 200Hz. Usable Range Data: Frequency Response Capability with TD crossover slopes removed.
  • [b] Sensitivity & Peak SPL: will depend on spectral distribution. Measured with band limited Pink Noise. Refers to the specified +/- 3dB range. Data are for Speaker + Processor + recommended amplifier combinations.
  • [c] Directivity Curves and Data 1/3 octave smoothed frequency response, normalized to On-Axis response. Data obtained by computer processing of off-axis response curves.
  • [d] Please refer to the GEO User Manual.

Nexo GEO CD18 Directional Sub-bass Dimension Diagram

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