Sundown SA-15 Enclosure Ideas?

[EraOfDiscovery]

The displacement would be added to the net volume not subtracted, just need to determine the volume of the cone delimited by the radiating surface, can't calculate without a diagram but it will be certainly small compared to the box net volume.

Opps, that's what I meant to say, was really tired when I wrote that. Alright I guess I'll see how they look both ways and see which one I like better. Oh and one more question that just popped into my head. Would there be any difference having dual ports vs the shared port that you disigned? I figured there wouldn't be, as I've seen plenty of boxes with shared ports.

[Joe X]

Rather than two ports something like the following, a more efficient alternative kind of port that doesn't split at the turn:

Problem is it's harder to build and is not self bracing, you need to add braces, the reason I didn't choose it is that the side ducts of the shared port in the first box are less than 3" in length and the area ratio is low on them also, so not much of an issue in this case, this latest box remains an option as well as the round ports alternative.