Dear Wayne, (or anyone who wishes to contribute) This post leads me to a related question: what volume do you use for woofers when figuring total volume for a cabinet? "Guestimating" the displaced volume doesn't seem accurate. I've thought about putting a cheap 15" woofer in a plastic bag and dunking it in a bucket of water to get the volume, but if someone else has come up with a good number, that's o.k. with me.