One active diaphragm, one passive diaphragm. An acoustic labyrinth between creates an acoustic delay to cancel sound arriving at 180 degrees. This is the cardioid polar pattern. Sound sources appear closer. The fattening effect is inversely proportional to distance. The GXL2400 is compact in design and big on sound. Internal hi-pass filter reduces thump and rumble. Elastic shock mount and protective pouch are included. P48 (48V) phantom power is required.