LDF= low density fiberboard
MDF= medium density fiberboard
HDF= high density fiberboard
particle board= what he used= what most pre-fab boxes and home audio speaker cabinets are made of...the best option?...No...but it works.
everyone here has had some boot-leg shit before at one time or another:crazy:
Building boxes is like fine wine...it takes time to get good.
Keep building...try some titebond and MDF next time.
Good luck