Wharfedale WLA-121SUBA Active Hybrid Curvature Subwoofer - 21"HYBRID CURVATURE ARRAY The WLA 1 Hybrid Curvature Array system.. is now.. ACTIVE. The WLA 1A active system incorporates all the incredible hardware features of its passive brother the WLA 1 System. The EVO Fold waveguides, the drivers created by Beyma in Europe and the Hybrid Curvature Array configuration are all included. but the new WLA 1A Active now brings powerful internal amplification and refined internal DSP processing to the party. It has