If it is net volume, shouldn't we add the volume of the driver, bracing, and port(s)?
That would be gross/total volume.
Is Vd displaced volume of air or is it the physical volume of the cone/basket/magnet inside the box?
I believe Vd is the amount of air displaced by the cone.
so, just to put it another way:
exterior volume - exterior panels = gross interior volume
gross interior volume - driver - bracing - ports = net interior volume.
net interior volume is the number winisd uses.
LTD I understand what net and gross mean but the way you are describing confuses me. let's say winisd suggests 100 ltrs net internal box volume and bracing/Vd/port take up collectively 15 ltrs. so, shouldn't the gross internal volume be 115 ltrs and i should build the box to 115 ltrs? coz when we minus the volume taken up by bracing/Vd/port (15 ltrs), the net is still 100 ltrs which is what winisd suggested.
you've got it.