The driver is rated for 225 watts. I happen to have a model open in WinISD Pro right now. With that amount of power in a 3 cu ft box it won't exceed X-Max (13 mm) unless you are trying to play content below 7 Hz. Per Mark Seaton the X-Mech is 20 mm. Therefore it should handle peaks of 550-600 watts without exceeding that excursion.