Answer
Yes, using two or more LS118 side by side, stacked, or back-to-back and engaging the appropriate cardioid setting (Forward/Rear) on each subwoofer will provide a cardioid coverage.
Yes, using two or more LS118 side by side, stacked, or back-to-back and engaging the appropriate cardioid setting (Forward/Rear) on each subwoofer will provide a cardioid coverage.