Polk Audio C-4 subwoofer port dimensions?

WhiteLX Posts: 4
edited February 2012 in Car Subwoofer Talk
I recently picked up a Polk C-4 subwoofer system but it is missing the port tubes. I was wondering if anyone had the dimensions, inside diameter and length, of the port tubes so I can get this system sounding correct. From an inside picture and some scaling, it looks like they are about 5" long and 3" OD, but I'd really like an exact measurement.


Post edited by WhiteLX on


  • WhiteLX
    WhiteLX Posts: 4
    edited January 2012
    well, I just opened it up and it seems some knucklehead changed out two of the 6x9s at some point with some generic brand coaxials with the tweeter removed. :mad:

    Anyone know of a suitable replacement or where I can get original replacements?
  • BigDWiz
    BigDWiz Posts: 14
    edited February 2012
    Glad to see your box has the terminals on the same side as mine. Based on the Ads and Polk literature, I was beginning to wonder...

    I posted your answer in another forum, but just in case someone finds this in the future and needs the info:

    3" OD, 2 7/8" ID, 5" Long, 3 3/4" flare on the front

    note: my iPhone's camera lens makes it appear the port starts at a larger ID and gets smaller, but it is a constant diameter, only the flare on the front lip is larger. The picture is just distorted due to the wide angle lens.


    See Old School Amps, Speakers and much more on my YouTube channel:

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