ST-218

Reflex Loaded Subwoofer

ST-218

Large format flyable reflex subwoofer

Current
Large format touring-oriented subwoofer
Four-point touring flying system
2 x 18″ neodymium high-excursion LF drive units
The ST-218 is a high power touring subwoofer system for applications where high SPL and extended low frequency response are required. ST-218 subwoofers are inherently scaleable – they can be used as single units, or in large numbers for filling arena or stadium shows. The substantial enclosure houses a pair of reflex-loaded 4.5” voice coil 18” neodymium LF cone drive units. As with all EM Acoustics products headroom is key: peak-to-peak linear cone travel is 28mm, meaning large amounts of low frequency energy can be accurately produced by a surprisingly small and lightweight subwoofer enclosure.
  • Large format subwoofer for applications where high SPL and extended frequency response are required
  • Integral four-point touring flying system
  • Protective floor runners and matching stacking recesses
  • Various transport, protection and flying accessories available
  • Impact and weather resistant black textured finish as standard
  • RAL colour and enhanced weather protection options

The ST-218 is a large format touring subwoofer, and whilst it is designed to be mechanically and acoustically compatible with the HALO-A system, it is a standalone product in its own right and can be used to support any EM Acoustics product – either in a flown or ground stack configuration.

The compact enclosure houses a pair of 4.5” voice coil, 18” (457mm) neodymium drive units, in a reflex design with a single low-velocity port to minimise distortion. The drive units’ high motor strength gives the ST-218 excellent transient response, and the moving area of the two high-excursion 18” drive units generate significant low frequency extension and overall output. The enclosure is symmetrical, so in both flown and ground stacked configurations one enclosure in every three can be rotated to create a cardioid array. Such arrays offer exceptional low frequency directivity control and significantly reduce the energy radiating to the rear.

The robust enclosure is constructed from premium 18mm (¾”) multi-laminate Birch plywood – rebated, screwed and glued together for maximum strength. The enclosure is finished in an impact and weather resistant black or white textured polyurethane finish as standard, though RAL colour matching and enhanced weather-protected outdoor options are available. Input is provided by a single NLT4MP connector on the rear.

The flying hardware has been built with touring flexibility and reliability in mind. The ST-218 uses a 4-point system, and all rigging components retract flush for transit and ground stack use. Ultra-high tensile steel parts form the core of the 4-point system, meaning arrays of up to 12 elements can be safely assembled with above-regulation safety factors. The mechanical package is completed by a mesh-backed stainless steel grille, eight recessed bar handles (four per side), protective stacking runners and mating recesses and attachment points for the optional castors on the rear.

The ST-218 requires external active high/low pass filters and a single amplifier channel to function correctly – as such it is recommended to be used with EM Acoustics’ range of Advanced System Amplifiers. It is however possible to use other DSP-enabled amplifiers, or conventional amplifiers with external DSP. Suitable DSP settings are provided on the EM Acoustics website. The amplifier should be capable of delivering 3500-5000W RMS into a 2-ohm load. For cardioid arrays, separate amplifier channels are required for the rear-firing subwoofer(s) due to the different processing needed.

Optional accessories include castor sets, multi-enclosure touring wheel-carts, flying grids and padded covers for both single enclosures and multi-enclosure carts.

Enclosure Type High power reflex subwoofer
Components 2 x 18″ (457mm) high excursion neodymium LF drive units
Dimensions (HxWxD), mm/(ins)  580 (21.7) x 1300 (51.2) x 850 (33.5)
Net/Shipping Weight 111/118kg (224/259.6lbs)
Frequency Response 28Hz – 150Hz ± 3dB
Maximum SPL 137dB continuous, 143dB peak
Loudspeakers per amplifier
(for full SPL output)*
DQ6: Not recommended, DQ10: Not recommended, DQ20: 1 per channel
Di06: Not recommended, Di10: Not recommended, Di20: Not recommended
Power Handling 2500W RMS, 5000W program
Nominal Impedance 2 ohms

* Higher numbers of loudspeakers per amplifier channel may be possible at reduced overall SPL.  Please consult the user manual for more details.

 

 

 

 

 

 

 

 

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ST-218

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Product Datasheet

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User Manual

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Date modified: 03-05-2024
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2D Product & Accessory drawings in DWG format

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2D Product & Accessory drawings in PDF format

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Revit Family

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Architects Specifications

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Acoustic Simulation Data

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Download all

ST-218

pdf

Product Datasheet

Size: 618.89 KB
Date modified: 25-01-2024
pdf

User Manual

Size: 22.29 MB
Date modified: 03-05-2024
zip

2D Product & Accessory drawings in DWG format

Size: 12.76 MB
Date modified: 25-04-2024
zip

2D Product & Accessory drawings in PDF format

Size: 2.27 MB
Date modified: 25-04-2024
rfa

Revit Family

Size: 9.95 MB
Date modified: 11-04-2024
docx

Architects Specifications

Size: 880.43 KB
Date modified: 10-05-2022
zip

Acoustic Simulation Data

Size: 1.00 MB
Date modified: 10-04-2024