> I don't think its shape or proximity to the apex are terribly
> important because the frequencies you'll be using the horn for are
> so low. Cut it round or square, whichever is easiest for you to
> do. I would position the woofer(s) near the apex and cut a hole
> for each woofer, located centrally, just over the dust cap. Are you sure that doing a seperate hole for each woofer is OK? What you are saying makes sense, just want to make sure - I guess the horn wouldn't know where the drivers at this low freq's + close spacing.