UL118B

It is fitted with a single high power 18" neodymium cone driver mounted in a double chamber band-pass speaker enclosure. This acoustic load provides an optimal efficiency gain as well as excellent control over the diaphragm displacement, which allows the mechanical reliability of the speaker and reduces distortion. This results in a superior dynamic capacity and an SPL gain of over 3 dB compared to a traditional direct-radiating vented enclosure.
The UL118B subwoofer has been designed for low frequency reinforcement from 25 to 80 Hz. The  cross-over point with UL210/D and or UL115B can be set depending on configuration.

It offers enormous versatility: infra-bass extension of a system in 4-way "complete mode" with UL210/D and UL115B or indeed bass and infra-bass extension in 3-way range "extended mode" with just UL210/D cabinets.
Furthermore, the integrated 4-point rigging system means the UL118B may be flown, stacked or used in cardioid configuration. Thanks to its design multiple UL118Bs can also be configured as controlled directivity cardioid and/or sub-arc designs. The Uniline system is fully controlled by digital APG processing which for complete library of presets are provided.