Port size for shiva application--please help

Discussion in 'Home Theater Projects' started by JoelTW, Apr 6, 2003.

  1. JoelTW

    JoelTW Stunt Coordinator

    Joined:
    Apr 1, 2003
    Messages:
    110
    Likes Received:
    0
    I cut out the bottom end cap for my sonosub (18.5"). It looks like I probably won't have room for the 4" flared port since it looks to be 5" diamater in pictures, and the shiva takes up most of the bottom end cap as it is.

    Is it better for the port to be on the same side as the driver?

    Should I get a 3" flared port instead?

    What length would the port need to be if my volume is about 142 liters?

    Thanks in advance!! [​IMG]
     
  2. Travis Cain

    Travis Cain Stunt Coordinator

    Joined:
    Jan 25, 2003
    Messages:
    79
    Likes Received:
    0
    I think it would be optimal to place the port on the top endcap. If you are concerned about things falling into it, you might consider putting a grill over it.

    We'll need to know what tuning frequency you want to give you a port length..
     
  3. David Lorenzo

    David Lorenzo Stunt Coordinator

    Joined:
    Dec 12, 2002
    Messages:
    198
    Likes Received:
    0
    I agree. Just put the port on top. There won't be any disadvantages sound wise. As far as port length, try downloading Win ISD Pro and play around with it a bit. It's very easy to use.
     
  4. JoelTW

    JoelTW Stunt Coordinator

    Joined:
    Apr 1, 2003
    Messages:
    110
    Likes Received:
    0
    What about dust collection? [​IMG]

    Also, with a 3" port Win ISD says 62 m/s air velocity and 32~ with 4".

    Can I just use a 4" pvc pipe on the bottom instead of the flared kit?

    [​IMG]
     
  5. JoelTW

    JoelTW Stunt Coordinator

    Joined:
    Apr 1, 2003
    Messages:
    110
    Likes Received:
    0
    I have another question... this may sound dumb

    If I plan to use just an LFE connection, I really don't need a Dual Voice Coil driver, do I? Just a waste of money?

    :b
     
  6. TimForman

    TimForman Supporting Actor

    Joined:
    Dec 4, 2002
    Messages:
    847
    Likes Received:
    0
    The DVC is going to allow you to choose the impedence you want (4 or 8 ohms) and allow you to feed it a bunch of power (650W). It's easy enough to put a stand-off type plate above and below the tube. There are many examples of other HTF members doing this on their Sonosubs. Mine sits horizontally so I don't worry about stuff falling into it. Plus, nobody in my house tries to shoot baskets into my sub. Shiva Column
    Oh yeah, your 3" port will need to be about 6 1/2 inches long.
     
  7. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,952
    Likes Received:
    0
     
  8. JoelTW

    JoelTW Stunt Coordinator

    Joined:
    Apr 1, 2003
    Messages:
    110
    Likes Received:
    0
    Thanks again for all the help [​IMG][​IMG]

    I'll try the pvc first since I don't plan to play it loudly [​IMG]

    i found winISD online port calculator... pretty nice
     
  9. Frank Mowry

    Frank Mowry Stunt Coordinator

    Joined:
    Mar 25, 2003
    Messages:
    57
    Likes Received:
    0
    In Adires vented box instructions it says if you're using straight pipe, to add 5" to the port length. Page 7 mid page.

    Frank
     
  10. David Lorenzo

    David Lorenzo Stunt Coordinator

    Joined:
    Dec 12, 2002
    Messages:
    198
    Likes Received:
    0
    You don't add 5 inches to the port length. You add it to the center tube length. The total port length would come out to be 1 inch less than a flared port.
     
  11. JoelTW

    JoelTW Stunt Coordinator

    Joined:
    Apr 1, 2003
    Messages:
    110
    Likes Received:
    0
    hmm.. Now you guys have me confused.

    I just ordered the 4" precision port from PE should receive it this week
     
  12. David Lorenzo

    David Lorenzo Stunt Coordinator

    Joined:
    Dec 12, 2002
    Messages:
    198
    Likes Received:
    0
    Joel. Just use the entire length pipe that comes with that kit.
     
  13. Frank Mowry

    Frank Mowry Stunt Coordinator

    Joined:
    Mar 25, 2003
    Messages:
    57
    Likes Received:
    0
    Ahh, I was wondering what I was reading. My bad, I'll keep my mouth shut now.

    Frank
     

Share This Page