Closed Thread
Results 1 to 8 of 8

Reload Thread: port area question

  1. #1
    stl_314's Avatar
    stl_314 is offline Senior VIP Member



    Join Date
    Dec 2011
    Location
    mo
    Posts
    338
    Post Thanks / Like
    Mentioned
    19 Post(s)

    port area question

    Why does everyone say your port area needs to be based on the size of your box? I have read posts on fb now were obsidian and dc both have said go by driver (ie. 15 needs this much, 18 needs this much. not even worried about the box size)







  2. #2
    hispls's Avatar
    hispls is online now CarAudio.com Veteran



    Join Date
    Sep 2009
    Location
    Cape Cod, Massachusetts
    Posts
    5,743
    Post Thanks / Like
    Images
    15
    Mentioned
    104 Post(s)

    Re: port area question

    Whatever number they give probably assumes you're using the proper volume for that size sub. Really the old conventional wisdom used to be based on cone area, but basing by box volume seems to work well enough in practice.




  3. #3
    RAM_Designs's Avatar
    RAM_Designs is offline SketchUp Master



    Join Date
    Feb 2006
    Location
    Rockwall, TX
    Age
    28
    Posts
    21,044
    Post Thanks / Like
    Images
    1
    Mentioned
    97 Post(s)

    Re: port area question

    Because really, required port area has absolutely nothing to do with what size box the sub is in. Whether it's in 1ft^3 or 5ft^3, the air displaced by the sub is going to be the big determinant of what is the "safe zone" for avoiding port noise. It's just that people tend to use the same size box for 10's 12's etc, so the rule of thumb tends to be ok in most cases.

    I know Nick at Obsidian is a big supporter of NOT using large ports, but using smaller aeros to maintain extension below tuning and keep peakiness down. And with aeros, it's easy to use a smaller port and not have to worry about port noise.



    1,400+ designs since March 2011...
    I have my PM's turned off, please email at Ryan@RAM-Designs.com

  4. #4
    stl_314's Avatar
    stl_314 is offline Senior VIP Member

    Threadstarter


    Join Date
    Dec 2011
    Location
    mo
    Posts
    338
    Post Thanks / Like
    Mentioned
    19 Post(s)

    Re: port area question

    My view on it though is, 18's can go from 4cubes to 10cubes depending on the sub. So thats over double the port area depending on the size of the box. So why does everyone keep recomending 15 in per cube. Why not start letting people know that is not the way to do it




  5. #5
    RAM_Designs's Avatar
    RAM_Designs is offline SketchUp Master



    Join Date
    Feb 2006
    Location
    Rockwall, TX
    Age
    28
    Posts
    21,044
    Post Thanks / Like
    Images
    1
    Mentioned
    97 Post(s)

    Re: port area question

    Quote Originally Posted by stl_314 View Post
    My view on it though is, 18's can go from 4cubes to 10cubes depending on the sub. So thats over double the port area depending on the size of the box. So why does everyone keep recomending 15 in per cube. Why not start letting people know that is not the way to do it
    Because people don't listen and are stuck in their ways...they will always recommend 12-16in^2 of port per ft^3.



    1,400+ designs since March 2011...
    I have my PM's turned off, please email at Ryan@RAM-Designs.com

  6. #6
    Moble Enclosurs's Avatar
    Moble Enclosurs is offline Box Designer/Builder



    Join Date
    Jul 2011
    Location
    Ledyard, CT
    Posts
    1,388
    Post Thanks / Like
    Images
    34
    Mentioned
    81 Post(s)

    Re: port area question

    No kidding. I dont know where that originated from, but get rid of that rule.





    Contact me for more info:[/COLOR][/I][/B]

    Mobile Enclosures:http://mobileenclosures.com
    Facebook:http://www.facebook.com/pages/Mobile-Enclosures/134158593281463
    YouTube Channel http://www.youtube.com/user/TheMobileenclosures

  7. #7
    pro-rabbit's Avatar
    pro-rabbit is offline Moderator pro-rabbit is a Supporting Member of the forum!

    pro-rabbit is a Supporting Vendor of the forum!

    Join Date
    Jan 2004
    Location
    OKC, OK
    Age
    32
    Posts
    12,395
    Post Thanks / Like
    Mentioned
    373 Post(s)

    Re: port area question

    Quote Originally Posted by RAM_Designs View Post
    Because people don't listen and are stuck in their ways...they will always recommend 12-16in^2 of port per ft^3.
    It is also hard to get people to look past this do to several companies suggesting this very method. With "dumb luck" it does tend to work some times.




  8. #8
    travicles's Avatar
    travicles is offline Senior VIP Member



    Join Date
    Jul 2009
    Location
    Louisiana
    Posts
    178
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: port area question

    I am interested in this. So if that rule should not be followed, what is the correct way to determine port area? Also, what is the difference between a small port and larger port? I have read a larger port creates a more peaky response, but I don't know if that is true.



    2007 Silverado Classic Regular Cab
    Clarion DXZ785usb
    MB Quart ONX4.125
    Hybrid Audio Imagine
    MB Quart ONX1.1500D
    SSA Icon 10"

Closed Thread

Similar Threads

  1. another port area question
    By nismboy6986 in forum Enclosure Design & Construction Help
    Replies: 1
    Last Post: 02-22-2005, 04:22 PM
  2. port area question
    By IgnoreMe in forum General Discussion
    Replies: 5
    Last Post: 11-26-2004, 12:30 PM
  3. port area question
    By guitar012345678 in forum Enclosure Design & Construction Help
    Replies: 10
    Last Post: 11-17-2004, 04:55 PM
  4. port area question
    By LuNaTiC in forum Enclosure Design & Construction Help
    Replies: 2
    Last Post: 10-13-2004, 10:15 PM
  5. Port Area Question
    By Acidburn in forum Enclosure Design & Construction Help
    Replies: 14
    Last Post: 04-30-2004, 01:01 AM

Posting Permissions

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

1e2 Forum