im new here but ive read enough to know who is knowledgeable.so any help would be greatly appreciated. can you swap tu7bular ports for square or rectangular vents by taking the internal volume of the cylinders and matching it to thevolume of the vent if you keep the same depth
Nah, you need to match crossectional area to use the same length. A square port with the same diameter as a round one needs to be longer to get the same tuning frquency because it has more area.
Don't look at volume. A really "wide" port can have the same volume as a "skinnier", longer one, but will tune much differently.
Length and crossection is what you need to worry about matching.