PowerNaudio 10+ year member
the power of audio
Hey you said on MY second picture the length would be calculated by adding 15+3+.75=18.75 Where did you get the 3" and .75" from. I know why you calculated 15 inches, because it is the actual length of the port, but i dont see why you added in 3 and .75 inches. Could you further explain that please
here is your image modified to help you understand it a bit better.
the values that i give you are assuming that the red line is 3", because you didnt provide any values for it. but you can go as small as 1.5" for the red line because the port is open on both ends which will still provide the proper port area for the port. any less and you will change the characteristics of the port.
so the math would be 15" + 1.5" + 1.5" + .75"=18.75"
for the end correction of my T port drawin. it would be 10.25+5.75+1, only if you taken into account the K factor before you made the drawing. you would calculate the port length and then add 1" to the physical length of the port to get the perceived length of the port.And on this one
http://www.putfile.com/pic.php?img=3305668
You would basically just have to calculate one side of the "T" port" so on that diagram you would just do 10.25+5.75+1 (cuz that is half of the width [2"]) or would you do 10.25+5.75+2 because the width of the "T" port is really 4 inches?
now if you are designing the port then once you calculate the port length you would take the 1" "on a 2" wide port" from the length of the port, to properly account for the K factor "port end correction".
about your T port. my drawing is a true T port "no baffle separating each port". your drawing is not a T port, but two L shaped ports back to back, so you would calculate your T port length and width of the port at the end of the port, just like you would for a regular L shaped port. and 12+7+1.5 is incorrect. assuming that the port end is 3" from the nearest wall and 3" wide. it would be: 12" + 7" + 1.5" + 1.5" + .75 + 1.5"= 24.25" of perceived port lengthSo to recall, so i feal assured on this, on MY first diagram, the T port with a wood board down teh middle to seperate the two ports, to calculate the length you would add 12+7+1.5(because that is half of 3,the width)
when you draw your port you don't draw the port with port end correction, because port end correction is a perceived length. its not the physical length of the port. you draw the physical length of the port. the same way it would be built.
yes to figured the perceived length of the port you would add 21.25+18.75+2 (half of the width) that will get you the perceived length, so you can find the tuning of the port. when you draw your port or build the enclosure. your port should look just like on the drawing.And also on your second diagram, the "L" port
http://www.putfile.com/pic.php?img=3305715
To calculate that length you would add 21.25+18.75+2 (half of the width)
well i hope that helped clear it up for you.
if not then ask away.