Posted June 26, 200817 yr I know how to get port area in square inches, but how do I find out the port length and tuned frequency? I need to know the math to aquire my goals. cant find anything on this specifically, only port area which i already know
June 26, 200817 yr Thats the tuning equation, if that's what you're looking for. To know the variables and how to use them, just go to jls website, it explains it pretty well. This is what i used to determine my tuning, as i really didn't trust the online calculators.http://mobile.jlaudio.com/support_pages.php?page_id=165
June 26, 200817 yr Solving For Length of Vent or Port Notek values:vent has one free end and one flanged = 0.732vent has two free ends = 0.614vent has two flanged ends = 0.850WhereLv = length of port or ventDv = diameter of port or ventDmin = minimum diameter of port or ventNp = number of ports or ventsVb = volume of boxfb or Fb = tuning frequencyk = end correction factorSd = surface area of subwooferVd = driver displacement volumeXmax = maximum linear displacement of driver
June 26, 200817 yr Important to note that "flanged" and "flared" are not even remotely the same. Flanged means that the end of the port is flush with a flat surface like an outside face of the box, whereas a free end is just the port sticking out into space like the open end of a PVC port inside a box withnothing around it. Flared means that there is a flare (like the bell on a trumpet) on one or both ends of the port. There are equations for that as well and they are somewhere in this forum. I built a fairly simple Excel spreadsheet for flared port calcs that DevilDriver hosted somewhere. Again there should be a link in that thread.
June 26, 200817 yr Important to note that "flanged" and "flared" are not even remotely the same. Flanged means that the end of the port is flush with a flat surface like an outside face of the box, whereas a free end is just the port sticking out into space like the open end of a PVC port inside a box withnothing around it. Flared means that there is a flare (like the bell on a trumpet) on one or both ends of the port. There are equations for that as well and they are somewhere in this forum. I built a fairly simple Excel spreadsheet for flared port calcs that DevilDriver hosted somewhere. Again there should be a link in that thread.IF you find that link please post it, I can add it to my bookmarks.
July 1, 200817 yr Important to note that "flanged" and "flared" are not even remotely the same. Flanged means that the end of the port is flush with a flat surface like an outside face of the box, whereas a free end is just the port sticking out into space like the open end of a PVC port inside a box withnothing around it. Flared means that there is a flare (like the bell on a trumpet) on one or both ends of the port. There are equations for that as well and they are somewhere in this forum. I built a fairly simple Excel spreadsheet for flared port calcs that DevilDriver hosted somewhere. Again there should be a link in that thread.IF you find that link please post it, I can add it to my bookmarks.http://www.soundground.ca/index/flared_port_calc.xls there it is...
September 30, 200816 yr So if Dv = the diameter of the port or vent, how would you measure this given a square port? Sorry if this additional question is redundant.
September 30, 200816 yr convert from a rectangle port to a circle port with equivalent areaThank you sir! I think I have got it.
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.