.....a Cadence X-Sub is rated up to 250 hz....I ask someone to try the higher range on their Cadence X-Sub and report....it will require sending full-range signals to the sub with cutting at sub-level, or an LFE cut of 250, but you want the sub's ability to cut below 250 at all times....see what it sounds like at 100, 150, 200, and 250, and I will owe you a favor.....