Pan headed wood screws are fine if you don't plan on removing and remounting the sub too often. If you want a more heavy duty mount or if your threads are stripping too easily then try T-nuts with machine screws. #8 or #10 depending on the mounting holes.
I didnt know what T nuts were so i googled them and it looks like that will be some thing i want to do. So to use them I just drill a hole the same size as the shaft:naughty: put the t nut on the bottom and Then Insert:naughty: the machine screws from the top?
Before you put in the sub, predrill all the holes then put the screws in, push them all the way down, then thread the T-nuts from the back and tighten the screws just enough so they begin to bite into the wood. Then you can remove all the screws and mount your sub and tighten them all the way.
X eleventy billionz on teh t-nuts. Especially if you want to try diff subs in the enclosure. Wood screws eventually strip the sockets they make when they go in and out a few times. T-nuts are fo eva.
OK well i put the Tee nuts in and omg took me forever to get them started. they kept on falling out when i would start to screw the bolts in, but i won in the end!