Page 1 of 2 12 LastLast
Results 1 to 15 of 16

Thread: Back reflex ports and corner placing

  1. #1
    Senior Member Guido's Avatar
    Join Date
    Apr 2003
    Location
    Germany
    Posts
    2,506

    Back reflex ports and corner placing

    If for space reason a big speaker (letís say a K2-9800 type) need to be placed in room corners, letís say 1 feet off the wall(s), is it then better to have the reflex ports to the front or to the back??

  2. #2
    Administrator Robh3606's Avatar
    Join Date
    Apr 2003
    Location
    Rocinante
    Posts
    8,159
    I almost always drop the ports on the back. That way the port loads into the corner and any port noise or leakage is not aimed at the listener. It also gives you a nice clean refraction free baffle. One foot should be enough room so it doesn't intefere with the function.

    Rob

  3. #3
    Senior Member
    Join Date
    May 2006
    Location
    Ireland
    Posts
    1,235
    I would put them at the rear in a large speaker. Bookshelf speakers are a different kettle of fish of course.

    Am I the only one here wondering what you are up to...Ummm, the mind boggles

  4. #4
    Senior Member sourceoneaudio's Avatar
    Join Date
    Dec 2006
    Location
    Arizona
    Posts
    1,214
    Rear for sure. Every wall/boundary gives you 3db more output/bass reinforcement.
    Like Andy said, what are you up to? Getting ready to climb the mountain?


    Jeff
    J/S-S1A
    Jeff-S1A

  5. #5
    Obsolete
    Join Date
    Apr 2003
    Location
    NLA
    Posts
    14,548
    Quote Originally Posted by Guido View Post
    If for space reason a big speaker (letís say a K2-9800 type) need to be placed in room corners, letís say 1 feet off the wall(s), is it then better to have the reflex ports to the front or to the back??
    Try to go with the largest vents you can and put them on the back.

  6. #6
    Senior Member soundboy's Avatar
    Join Date
    Mar 2004
    Location
    Oregon
    Posts
    211
    I have two B460 clones, with the 2245's and 3 ports in the back, facing the wall, in a corner, in two different systems. Other than having to re screw all of the sheetrock to the studs facing them, they are very tight and sound great below 70-80hz. This also leaves the fronts smooth, except for the "Loudspeaker Components by JBL" vintage logos

  7. #7
    Senior Member
    Join Date
    Apr 2003
    Location
    UK
    Posts
    256
    The best solution I've heard has been to port out of the bottom of the speaker. It's clever. It certainly seems to make the speaker easier to position in the rooms I have tried. Rear facing ports are a mare here in the UK.

  8. #8
    Senior Member DavidF's Avatar
    Join Date
    Apr 2003
    Location
    San Jose CA
    Posts
    923
    Quote Originally Posted by merlin View Post
    The best solution I've heard has been to port out of the bottom of the speaker. It's clever. It certainly seems to make the speaker easier to position in the rooms I have tried. Rear facing ports are a mare here in the UK.
    'Oy, what's a "mare", Merlin?

    DavidF

  9. #9
    Senior Member
    Join Date
    Apr 2003
    Location
    UK
    Posts
    256
    Apologies David - an abreviation of the word nightmare. I missed an apostrophe.

    I've never heard a rear ported speaker that was easy to position in room without eating into valuable listening space.

  10. #10
    Senior Member grumpy's Avatar
    Join Date
    Oct 2003
    Location
    SoCal
    Posts
    5,436
    hah... I figured it was as in "old grey..."
    (sort of fit the intent, if I'm reading right) -grumpy

  11. #11
    Senior Member Guido's Avatar
    Join Date
    Apr 2003
    Location
    Germany
    Posts
    2,506
    Thanks for help!

  12. #12
    Senior Member
    Join Date
    Sep 2006
    Location
    San Jose
    Posts
    847
    I think you're going to find that it is very room dependent. In some rooms you have to get the woofer out of the corner and off the floor. So, in genera to the rear, but not necessarily.

  13. #13
    Member
    Join Date
    Feb 2007
    Location
    long beach, new york
    Posts
    32

    rear port

    I know that we get a rise in efficiency when we corner load(can you say KlipchHorn?). However with the general inability to predict room loading characteristcs, until you actually put the enclosure there, I believe you are better off designing a system that does not rely on them. There's good reason why Jbl as well as others will usually port on the same baffle as the woofer. I have seen side firing woofer with front firing ports. True ,a ported design must be done properly to eliminate the problems mentioned in the earlier response. Down firing is very popular in the uk ,but it has its own problems, such as the nature of the floor you are bouncing that bass off of! RC

  14. #14
    Obsolete
    Join Date
    Apr 2003
    Location
    NLA
    Posts
    14,548
    Quote Originally Posted by rich carnese View Post
    There's good reason why Jbl as well as others will usually port on the same baffle as the woofer.
    JBL has been placing the ports in the back since ~ 1984. It is done to mitigate spurious response. The correct solution is to get the prototypes made and see what works best in a specific environment. That's why we bother with building prototypes.

  15. #15
    Senior Member
    Join Date
    Apr 2003
    Location
    UK
    Posts
    256
    Quote Originally Posted by rich carnese View Post
    . Down firing is very popular in the uk ,but it has its own problems, such as the nature of the floor you are bouncing that bass off of! RC
    Not if you fire the port a controlled distance onto a base plate ala Proac's newer Response series. In contrast with traditional designs, I've yet to find a Proac that's difficult to place. See the slot at the base of these puppies


Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

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