Ported box building question.

[LightningStryk7 10+ year member]

Alright guys can somone tell me if the volume for a ported enclosure includes the port volume? Im guessing that it does not. Also if im making a rectangular box. Can I put the port going strait back on the right side... Kind of hard to explain... what I meen is if my vent is on the right side of the box and I make a port slot that goes parallel with the sides and goes to the back but not all the way so theres still an area to pass air through. Like this little drawing i jsut made. Can I do that? or do I need to curve a slot in the back also that connects off of the port slot thing. you guys understand? //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

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[swimfreak26 10+ year member]

I don't understand what you're getting at with the whole port idea and bending, air flowing, etc..

BUT, as far as air space is concerned, it does not include the port volume. The NET enclosure volume, which is what you hear people speak of when they say "I'm in 3 cubes tuned to..." is the volume after speaker, port, and port wall displacements are taken into account.

To give you an idea, a box that is 44 x 12.5 x 19.5 will give 4.86 cubic feet GROSS, but after a 54sq inch port tuned to 33 Hz, and .2 feet driver displacement, you get a NET volume of about 3.5 cubes...so the enclosure, though encompassing 5 cubes of air, is only 3.5 cubes.

 

[LightningStryk7 10+ year member]

Quick reply.. I was trying to fix my box drawing it came out diferent then it showed here... in this typing area. SO when desiging a box I should put the total cubes with the port? then figure out the port tuning then get the box volume?

And my other question was kind of like can I just make the port have 1 wall with the air entering the back side like going strait in the prot then turnign left at the back to enter the box area.. or do I need to add another peice of wood to extend the port? or is that just for tuning purposes.