I thought maybe you could point me in the right direction on this. I want to build a 4th order bandpass enclosure for two 12" subs, but I can't seem to find any consistency on the web as far as calculating box volume. Basically I want two sealed chambers, each with their own driver, and one vented chamber in the center for both to play through. One site I was on simply said to double the Vas number and proceed as if it was a single speaker box, but would I split the sealed box volume between the two woofers? Another site said that to do it the way I want you would calculate the same as a single driver, then double the volume of the ported chamber (in effect, putting two 4th order enclosures together, joined at the port).
Being cool makes my head hurt! It's entirely possible the two designs I described above are the same, and I'm just not seeing it. An easy to follow formula from someone who knows what they're talking about would be very helpful.