For all of you audio buffs out there na mahilig sa D-I-Y, check out this site:

HiFi Speaker Design

It's a great site for info on building them speakers of yours. The site also offers neat downloads (e.g. absorption coefficient charts, an electronic calculator to computer for electronic values -ohms, power calculation, etc.-, a speaker box designer). You can even compute for the volume of your loudspeaker boxes on-line.