K Sub 1801 dp
5 Operation
12
5.7
Cardioid Mode
The Cardioid Mode serves to generate a cardioid response pattern for the subwoofers. Using this
mode, a significant reduction in bass energy emission to the rear of the system can be achieved. A
minimum of 2 subwoofer units is required. Multiples of three is better. Specialised signal processing
creates controlled interference patterns between the sources, leading to the desired cancellation to
the rear.
In order for the interaction between the sources to function correctly and generate the desired car-
dioid response, the subwoofer system must be set up at least 1.5 m away from any bordering sur-
face such as a wall or solid stage front.
Installation using two subwoofers:
The K Sub 1801 dp that is in Cardioid Mode must be positioned such that the front of the unit is
facing the rear, whilst a second K Sub 1801 dp which is not in Cardioid Mode faces the front as
normal. The level of the rear-facing K Sub 1801 dp must be reduced by 3 dB compared to the front-
facing subwoofer if the cardio system consists of only two subwoofers.
Note:
Both subwoofers must be set to the same cut-off frequency. The cardioid preset of rear-facing
subwoofer must be activated and the level has to be reduced by 3 dB.
Application example:
Only the rear-facing subwoofer is operated in Cardioid Mode. This applies regardless of whether
the two units are stacked on top of each other or laid side by side on the ground.
e.g. K Sub 1801 dp
100 Hz, not in Cardioid Mode, Level 0 dB
K Sub 1801 dp
100 Hz, Cardioid Mode, -3 dB
