When using two Sub1 or Sub2 powered bass modules, Cardioid Mode allows you to localize your bass directly in front of your L1 system. Cardioid Mode is ideal for outdoor events and keeping the stage and microphones free of low-frequency feedback. Instead of bass invading your space on stage or upsetting the neighbors, Cardioid Mode negates rear-firing bass energy by -10 dB and focuses it out front where you want it.