The ULT18 Active Sound-Reinforcement Subwooferfrom PreSonus is an 18" custom woofer with a 4" voice coil driven by 2000W of Class-D power in a direct-radiating ported enclosure. Designed to complement any full-range PA loudspeaker, it can be used to deliver low-frequency performance in sound-reinforcement applications for live stage, theater, clubs, and more.

The speaker inputs feature two combo XLR-1/4" connectors with direct outputs and polarity invert. The subwoofer's low-frequency transducer and voice coil provide 7mm of driver travel before reaching over-excursion. This allows it to push more air and bring more thump. In addition, a built-in variable low-pass filter lets you dial in the upper-frequency limit.

Designed with M10 fly points, ground-stacking provisions, castor provisions, and a defeatable front-panel LED, the ULT18 active subwoofer is a suitable choice for both mobile or install applications.

18-inch custom low-frequency driver with 4" voice coil

2000W of Class-D power

Two combo XLR-1/4" inputs with direct outputs

7 mm driver travel before over-excursion

Defeatable front-panel LED

Rugged, texture-painted birch enclosures with tour-grade 16-gauge steel grille

Comfortable ergonomic handles


PA Speaker
Configuration Active Subwoofer
Total Power Capacity 2000 W Peak 
LF Driver 1 x 18" / 45.7 cm Woofer
LF Voice Coil 4" / 10.2 cm
Frequency Range 42 Hz to 250 Hz ±3 dB
Maximum SPL 135 dB
Signal Processing
Crossover 90 Hz
Mounting 12 x M10 
Dimensions 22.5 x 24.5 x 25.0" / 57.1 x 62.2 x 63.5 cm
Weight 90 lb / 40.8 kg

PreSonus ULT18 Active Sound-Reinforcement Subwoofer