Custom Speakers

Im planning in making my own diy speakers. I have old diamond audio speakers which are 4 watt per channel of output. For me i dont need more and im not planning to play a concert. I would like to know what kind of foam should i put in there. They currently have some inside but after swapping to wood the technical aspect will change a bit to have a the best sound. Is normal foam from diy stores good or should i get some pro noise dampening foam to make my bass basy?
Also i think this would be a very interesting tutorial for logan to do as he is very audio oriented and really listens to a lot of music "he claims".