cardioid

 
cardioid
1 kHz 250 Hz 500 Hz
1 kHz 2kHz 4kHz
1 kHz 8 kHz 16 kHz

 
cardioid

 
cardioid
125/250 Hz - 500 Hz 1 kHz 2 kHz
1 kHz 4 kHz 8 kHz 16 kHz