they are rated to the same wattage...
but amp 'X' cant produce a proper signal at its rated wattage.
however if you would like to play thoes games....
THD% rating plays a large part in sound. though many woofers roll off before the harmonics registered frequincy can be played loudly, you are still wasteing valuable excursion and power with the woofer trying to produce frequincuies higher than they are ment to be played.