Closed Thread
Results 1 to 11 of 11

Reload Thread: somethings fishy...

  1. #1
    Boosted92HB's Avatar
    Boosted92HB is offline Member



    Join Date
    Sep 2004
    Location
    Albany, GA
    Posts
    62
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    somethings fishy...

    I just plugged in some #s on a port calculator and...
    box is 8 ft.^3
    2 RE SE 15's
    ported to 35Hz...
    4x16.75 port
    Now here comes the weird thing...
    It tells me that I only need ~12" of port length. Is this correct? seems like everyone here is running some 20+ inch long ports while still being tuned in the mid 30's. Is this setup more along the lines of SPL than SQ? Im going for about a 50/50 mix of the two...







  2. #2
    Simos's Avatar
    Simos is offline Junior Member



    Join Date
    Sep 2004
    Location
    Des Moines, IA
    Posts
    22
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: somethings fishy...

    Your calcs are correct. You only need a 12" long port because your box volume is so high. As box volume increases, port length decreases, and as port cross sectional area decreases, port length decreases. However, as you decrease your port cross sectional area, you run the risk of port noise.




  3. #3
    req's Avatar
    req
    req is offline am a mod.



    Join Date
    Jul 2004
    Location
    Syracuse, NY
    Age
    32
    Posts
    15,426
    Post Thanks / Like
    Images
    21
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: somethings fishy...

    may i ask what calculator you used?




  4. #4
    Simos's Avatar
    Simos is offline Junior Member



    Join Date
    Sep 2004
    Location
    Des Moines, IA
    Posts
    22
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: somethings fishy...

    The port calculator I used was one I put together in Excel. It will solve for tuning frequency, net box volume, or port length.




  5. #5
    vincemarq's Avatar
    vincemarq is offline Member



    Join Date
    Sep 2004
    Location
    San Diego, CA
    Posts
    133
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: somethings fishy...

    Hey Simos, you think you could PLEASE tell us how to input the port calc formula into Excel? I'd be very greatful! Thanks a bunch!




  6. #6
    Simos's Avatar
    Simos is offline Junior Member



    Join Date
    Sep 2004
    Location
    Des Moines, IA
    Posts
    22
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: somethings fishy...

    I attached the excel file I put together as a zip file. Not sure if it will work to attach it as a zip file or not. It should be fairly self explanatory as to what you need to do. The cells that are highlighted red contain formulas, so dont type any values in. The cells highlighted green require a value.
    Attached Files




  7. #7
    tRiGgEr's Avatar
    tRiGgEr is offline CarAudio.com Veteran



    Join Date
    Jan 2004
    Location
    San Diego, Ca
    Age
    35
    Posts
    12,794
    Post Thanks / Like
    Images
    1
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    5 Post(s)

    Re: somethings fishy...

    Quote Originally Posted by Simos
    I attached the excel file I put together as a zip file. Not sure if it will work to attach it as a zip file or not. It should be fairly self explanatory as to what you need to do. The cells that are highlighted red contain formulas, so dont type any values in. The cells highlighted green require a value.
    It is not 100% accurate but fairly close. I recommend doing it by hand or on the computers sientific calculator.



    Quote Originally Posted by Scoobydoo View Post
    Before poking fun at others at least learn to spell. I won't go into all the gammar mistakes!
    Irony?

    Quote Originally Posted by audioholic View Post
    Your sig... Im trying to figure out if you think he spelled grammar wrong. Because, he didn't. Irony indeed.

  8. #8
    Simos's Avatar
    Simos is offline Junior Member



    Join Date
    Sep 2004
    Location
    Des Moines, IA
    Posts
    22
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: somethings fishy...

    Why is it not 100% accurate?




  9. #9
    Simos's Avatar
    Simos is offline Junior Member



    Join Date
    Sep 2004
    Location
    Des Moines, IA
    Posts
    22
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: somethings fishy...

    Seems to be accurate to me, unless you feel its important to have better than 1/100th accuracy.




  10. #10
    vincemarq's Avatar
    vincemarq is offline Member



    Join Date
    Sep 2004
    Location
    San Diego, CA
    Posts
    133
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: somethings fishy...

    Thanks Simos for the formula!




  11. #11
    Simos's Avatar
    Simos is offline Junior Member



    Join Date
    Sep 2004
    Location
    Des Moines, IA
    Posts
    22
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: somethings fishy...

    Quote Originally Posted by vincemarq
    Thanks Simos for the formula!
    No problem man, glad I could help.




Closed Thread

User Tag List

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may post attachments
  • You may edit your posts
1e2 Forum