Im sure you probly know all i am about to say, but it bears repeating. MDF is horrible stuff,its made with seriously harmfull chemicals. With that said, use a good quality mask and eye protection when cutting, routing or sanding. Make sure to seal the box well and coat both the inside and outside with paint . The box will stink up the house for weeks on end if this is not done. A trick i picked from the avs forum, if you want the sub flush mounted (and dont have a router) you cut a hole the size of the woofers outter dimension on your front panel. On the back of the panel mount a second panel with a smaller diameter hole cut in it. Oh and the T-nuts can be difficult when you have 8 holes and screws to line up. I drilled all 8 at once which was a mistake.Next time i will do it in groups of 2 , i tend to get in a hurry as the project get near the finish line . grin