Compact 2 x 8-inch driver line array element providing 90°/120° of horizontal dispersion and 0° to 15° splaying angle between modules. M28 features innovative CompassRigTM and REDLockTM rigging, enabling any size of system to be flown safely by a small team. Compass RigTM allows pre-setting of inter-cabinet angle values. REDLockTM handle locks front rigging points from rear of cabinet. All adjustments made from one position at rear of cluster.

Key Features

  • 2 x 8 inch LF Drivers
  • 2 x HF Compression Drivers
  • 141dB peak SPL
  • Frequency response: 65Hz-19kHz
  • H234mm/W575mm/D653mm
  • 37Kg/82lb


Frequency Response65Hz – 19kHz ±3dB
Usable Range @-6dB60Hz – 20kHz
Sensitvity 1W@1m106dB SPL Nominal (120° horizontal coverage) 107dB SPL Nominal (90° horizontal coverage)
Peak SPL@1m140dB Peak (120° horizontal coverage) 141dB Peak (90° horizontal coverage)
DispersionConfigurable 90°-120° Horizontal x 0-15° vertical
Available Crossover Frequencies900Hz (Active)
Nominal ImpedanceLF: 8 Ω (6 Ω min) - HF: 8 Ω (6 Ω min)
Amplified ControllerNXAMP4x4 - 3xSTM M28 in parallel on 2 NXAMP4x4 channels - 2x4000W/2Ω


ComponentsLF: 2 x 8" (20cm) high excursion 16 Ω Neodymium drivers
HF: 2 x 2.5" voice coil, 1.4" throat Neodymium 16 Ω drivers, Ketone Polymer diaphragm
Height x Width x Depth234 x 575 x 653 mm – 9.2" x 22.6" x 25.7"
Weight: Net37 kg – 82 lbs
Connectors2 x NLT4-MDV Speakon 4 poles
ConstructionPU Composite Low Density – Polyurethane water based black coating
Fittings2 x side handles / 1 x rear handle
Front FinishPerforated Dark Grey Metal Grille
RiggingIntegral 3 points flying system. Intercabinet angle adjustments from 0.2° to 15° in logarithmic steps.
System Operation
Electronic ControllerThe NEXO NXAMP4x4 presets are precisely matched to the STM Series cabinets and include sophisticated protection algorithms. Using STM Series cabinets without a properly connected NEXO NXAMP4x4 will result in poor sound quality and can damage components.
Speaker cabling1-/1+: LF - 2-/2+: MF/HF