The subsonic filter in the SMS-1 cannot be disabled. You can set it to its minimum position (15Hz), or you can disable the subsonic filter in the SVS's and move the SMS-1's subsonic filter to 20Hz (assuming that can be done), or you can download updated firmware from Velodyne and set the subsonic filter to 5Hz (there's a new firmware available from their site, but the only change is the ability to lower the subsonic filter to 5Hz).