SB acoustics SB29NRX2-00 205 gram, 10″ Passive Radiator
The version has less mass pre-added to the cone. It is used in the Helios CM by Javad and Jeff.
A great alternative to a vented cabinet when coupled with the SB29SWNRX subwoofer. The passive radiator design eliminates vent noise. Home theater systems greatly benefit from PR designs.
Cabinet size is quite reasonable – .75 to 1.0 cu ft. tuned to 35Hz This PR features the same heavy cast frame as its subwoofer counter-part along with a rubber surround and tune-able mass system.