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View Full Version : Port correction ?



Trixter
11-18-2003, 08:38 PM
I know that when a port shares a common wall of the box you need to account for the correction factor. But let's say that I am putting the port between 2 sub and the top and the bottom of the port (the small sides) share the top and the bottom of the box's walls? Does the correction still play a factor?

havoc06
11-19-2003, 09:01 AM
it is my understanding that anytime you use an enclosure all at all you must use the correction factor. Again, unless your building a huge spl box, were only talkin an inch or two off the total length so its not that big a deal if you dont do it.

Trixter
11-19-2003, 10:45 AM
But is it the same....add 1/2 of the port's width to the length? Or is it different since I'm am using two walls instead of one? The small walls and not the big one??

phoneman
11-19-2003, 08:22 PM
But is it the same....add 1/2 of the port's width to the length? Or is it different since I'm am using two walls instead of one? The small walls and not the big one??

If I am understanding you right then you will not need to factor in corection unless the larger side of the port is sharing a wall, Just for instance if you had a port that was like a 3x16 slot and only the 3" ends were sharing the wall then you would not need port correction factored. Think about it, If the small ends shared the same kind of rules as the large one then you would in theory have to add 8" of port correction to a 3x16 port and that just would not be right. So dont worry about it becuase you should be fine

BDIDDY
11-19-2003, 08:44 PM
correction factor???

phoneman
11-19-2003, 09:07 PM
correction factor???

Port correction factor is used when you build a slot style port and it shares a wall with the box. Like if you built a box with a 3x16 rectangular port and it was built so that one of the two 16" walls was also a wall in the box (port built against a wall in the box) making it so that walls length extended past the length of the port the you would have to take half of the width of the port (half of 3" would = 1.5" in this case) and add it to the port length to get your actual overal port length with correction factor. So if you were going to build a port like this and the design called for an overall port length to get a desired frequency you would make it 1.5 inches shorter to allow for port correction. Also when you measure a port with bends or L's in it make sure you measure down the center of the port and not the walls because you can be thrown off quite a bit if you dont.

Trixter
11-20-2003, 07:54 PM
Think about it, If the small ends shared the same kind of rules as the large one then you would in theory have to add 8" of port correction to a 3x16 port and that just would not be right.

Yeah I guess your right. I didn't think about it that way. Thanks.