EBS Shiva Port sie

Discussion in 'Home Theater Projects' started by Stuart Mundy, May 1, 2003.

  1. Stuart Mundy

    Stuart Mundy Agent

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    Hi All after living with a sealed 88 litre shiva for some time I've plucked up the courage to have a go at making the EBS alignment as per their web site .
    Only problem is this is! I am looking for some assistance is in the port size / lenght.
    In Oz it is very dificult to get the correct flared port so I have purchased the closest thing to the FP-4 recomended from the Adire site, this is a non flared port of 4 and a quarter inchhes in dia. Can anyone advise me on what the lenght the port should be for the 142 litre EBS tuned to the same Hz as the "standard" alignment
    Many thanks
    Stuart
     
  2. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    My calculations for a 4.25" diameter port tuned to 18.1hz in a 142.5L enclosure equals a 20" long non-flared port.

    It also makes sense because when you increase the diameter of the port, you have to increase the length.
     
  3. Stuart Mundy

    Stuart Mundy Agent

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    Many thanks Chris, I will put this into practice tomorrow, I can't wait to hear the difference between the two subs.
     
  4. Stuart Mundy

    Stuart Mundy Agent

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    Chris would it matter that the top of the port will only be about an inch from the top of the box ?
     
  5. KyleGS

    KyleGS Second Unit

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    You should leave 4.25" of space b/w the end of the port and any wall/obstruction.
     
  6. Stuart Mundy

    Stuart Mundy Agent

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    Am I right in assuming that given that there is not enough room in the box to have that lenght of port and still leave sufficient clearance that I can put a series of bends in the port ?
    Thanks
     
  7. Stuart Mundy

    Stuart Mundy Agent

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    Questions questions questions ! Looks like it all a bit hard to get bends for the 4.25 " port so as to give it suficient clearance .
    Would I be right in assuming that if I use a 4" PVC pipe for the port that the lenght for the Adire EBS alignment would be the twelve inchs as recomended from their web site plus 5" in an 142 litre enclosure?
    Thanks
     

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