When using multiple subwoofers you sometimes read that you have to gain match subwoofers before anything else.
You do this by setting up the subwoofers in the same location one after another and adjusting the volume till every sub has the same loudness.
But as long as your room is not symmetrical in every possible dimension you will need to level-match the subwoofers on your seating location anyway.
You can absolutely skip the step of gain matching.
With our subwoofers, it is even easier as the all have an Input-Gain setting separate from the volume control, for even better integration with your system.