Answer

The benefits of a cardioid sub are tremendous. Many venues suffer from too much low-frequency “build-up” on stage , resulting in a muddy Front-of-House mix and on-stage rumble that makes it difficult for performers to properly hear their instruments or stage monitors. 

A large contributor to this stage volume can be the rear energy coming off the subwoofers. A Cardioid Subwoofer dramatically reduces low frequency energy on the stage, thereby dramatically reducing low frequency “Spill” into the open microphones, thereby dramatically cleaning up the Front-of-House mix. 

Cardioid subwoofers are also useful when noise control at the boundary line is an issue, such as in outdoor applications.