yeah it does matter...particle board is larger paricles and it is not baked the same way the dust/resin mixture is to make mdf.....particle board is ok for low power subs in small encolsures, beoynd that it flexes like hell and can the possibility to actully explode/implode (i have seen it happen). I am not going to garontee you have problems But i would certainly advise you not to use that box if it is particle board (I still cant tell, the pictures are playing with my mind //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif )