Porting my sub

Discussion in 'Archived Threads 2001-2004' started by AlexKunec, Mar 14, 2002.

  1. AlexKunec

    AlexKunec Stunt Coordinator

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    Im building a sonotube shiva with a port tuned to 22hz(not flared). Is a 4" port big enough?

    Also, the length of the port that lspCad calculates, is that how long the port has to be inside the box, or how long it has to be in total? (Does the length count the thickness of the enclosure that it goes through?
     
  2. Harry Lincoln

    Harry Lincoln Stunt Coordinator

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    I have two shiva sonotubes tuned to 16.5hz with 4 inch ports, although I do have small flares on the ends (20mm radius cut into the endcap with a router). I have reached some high spls (130db) with no signs of port compression, although at that level the room and everything in it is shaking that bad I probably wouldn't notice it anyway[​IMG]
    Measure the port from the inside of the port tube, top to bottom, it makes no difference if the port is inside the cabinet or protruding from the cab, it is still measured the same.
    If you can, put flares on the ends of your port. I looked every where locally for a 4 inch flare, couldn't find one so I had to use a router to flare the top endcap, on the bottom of the port I did baically the same thing, put a piece of mdf about 7 inch diam on the end of the port and used a router to cut a flare into it.
    Harry.
     

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