GHXAMP 6.5 inch 178mm Bass Radiator Horn Passive Radiator Instead of an inverted tube 2PCS
Focal Shape 65 — 6.5" Active Studio Monitor with Dual Passive Radiators - Monitor Systems - Professional Audio Design, Inc | Professional Audio Design, Inc
GHXAMP 6.5 INCH 160MM Boost Bass Passive Radiator Speaker Rubber Vibration Membrane Plate For 6.5 Inch Subwoofer Speaker DIY