SEAS SP18R - H9944 Passive Radiator

The SP18R - H9944 6.5'' Passive Radiator from SEAS is a high-quality passive emitter engineered to elevate the low-frequency performance of your loudspeaker design. By replacing a conventional port in a bass-reflex enclosure, this component delivers deeper, more controlled bass extension while eliminating the turbulence and chuffing noises often associated with ports. It is an ideal choice for audiophiles and DIY enthusiasts seeking to refine the sonic character of bookshelf speakers, subwoofers, or custom multi-way systems.

This passive radiator is designed to work seamlessly with a separate active driver, allowing you to achieve a more natural and articulate low-end response. With a resonance frequency of just 26 Hz, it excels at reproducing the deepest notes with authority and precision. The equivalent volume (Vas) of 41 litres and moving mass (Mms) of 21.5 grams ensure optimal tuning flexibility, while the mechanical compliance (Cms) of 1.74 mm/N and cone area (Sd) of 13 cm² contribute to its efficient energy transfer and linear behaviour.

Crafted by SEAS, a brand synonymous with Scandinavian engineering excellence, the SP18R features a robust suspension and a carefully damped cone for minimal distortion. Whether you are upgrading an existing design or building from scratch, this passive radiator offers a reliable and sonically rewarding solution for enhancing low-frequency output.