Creating NT Subwoofer Cardioid Arrays

The Cardioid button on NT Subwoofers is optimized for arrays of three items. This could
be a groundstacked array of three subwoofers arrayed horizontally, or three flown in
a vertical array. In both cases, it is recommended the middle subwoofer be deployed
facing backward. Pressing the Cardioid button on the middle speaker then engages the
processing needed (delay, polarity inversion, and EQ) to accomplish a true directional
array.

It is possible to deploy a Cardioid array of two items in this same fashion, but the results are
not nearly as effective when it comes to directivity.