I bought an old cab with two Altec Lansig 418B (15")speakers. I really like it´s oldschool mids and highs. (I will use a sub of some kind for lows but thats an other story). I would like to make two separate 1x15" of my 215, preferably in a size like Bag Ends s15d. How important is the dimetions of the cab if its sealed? The cab is sealed now and I like that sound. Can I measure the existing cab and devide it´s volume with two to get the volume needed for one of the speakers? Is it the volume of the cab that is important or is it the depth, hight etc...?