Yes, you should be OK. The rumor is that the 225i and 325i use the same driver (or, they're selected the same - 0.5 tolerance levels). I have a few 225s with the rear holes opened - the improvement is noticeable. Plus, as Chris said earlier, one can reverse the hole tricks - to a degree by covering them again with some muslin fabric. I've used felt before to cover them - as it seems to retain the bass, but not allow it to be overwhelming if you're opening 10 or so holes.