Large box sealed subs...

Discussion in 'Archived Threads 2001-2004' started by Dan M~, Nov 14, 2002.

  1. Dan M~

    Dan M~ Second Unit

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    What are the advantages/disadvantages of large volumned sealed subs? I have a Tempest in a 3 Ft^3 sealed box and I am thinking of building a 5 Ft^3 sealed box. What should I expect? What am I gaining and losing?

    Thanks,
     
  2. Assuming heavy fill and no leaks, then going from 3-->5 ft^3 changes your Q from 0.677 to 0.588

    you gain more output below 40hz (+ almost 2db at 20hz), and loose some bass between 40-up....but not very much

    Ultimately, you will have better group delay (good for music), lower Q (0.6 is pretty good for music), lower extention (better for HT), but slightly less upper bass (not as good for HT). You also "gain" the need for less power to reach x-max at 20hz


    anyone else?
     
  3. Jack*Mains

    Jack*Mains Stunt Coordinator

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    Stupid question, but: is it necassary to fill a 142.5L sealed sub with polyfill?

    Is the same necassary for vented?
     
  4. You don't stuff a ported enclosure, but rather line the walls.

    You don't need to stuff a sealed enclosure, but doing so will make it appear larger and may help with the backwave of higher frequency harmonics.
     
  5. Chris Carswell

    Chris Carswell Supporting Actor

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    Funny, I stuffed my ported Tempest [​IMG]
     
  6. Dave_Gib

    Dave_Gib Stunt Coordinator

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    I stuffed my ported enclosure it acted noticeably bigger
     
  7. you can lightly stuff a ported enclosure, but I wouldn't recommend a heavy fill!
     
  8. Chris Carswell

    Chris Carswell Supporting Actor

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    I guess it's what one consider a "heavy fill".
    I've got a Tempest in a 24x27x19 box (~5.8 cu ft). Way too small for its full potential. I didn't feel like making a new box so I stuffed it with 60oz of fill to get the cu. ft up. It's important to keep a clear path to the ports so they don't get plugged up & can work properly.
     
  9. Dave_Gib

    Dave_Gib Stunt Coordinator

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    I just added a pound and a half I had around, put it in an 8 cu.ft. ported box for 4 12" Dayton DVC's, I didn't turn it on right away, I kind of forgot about it until later, I noticed the bass was alittle deeper, then I remembered I put that stuffing in it, so I know it wasn't the placebo effect
     
  10. Dan M~

    Dan M~ Second Unit

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    Anthony_Gomez,

    Thanks for the info.

     
  11. Dan M~

    Dan M~ Second Unit

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    Bump...
    [​IMG]
     
  12. less upper bass just means that you will end up with a shallower rolloff starting at a higher frequency
     
  13. Dan M~

    Dan M~ Second Unit

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    Thanks Anthony...

    Additional questions if you don't mind...

    If I incorporate an LT into the system, it seems that a larger enclosure would require less power then a small enclosure to achieve the same SPL down low. Is this true or am I missing something?

    Thanks again for the guidance.
     
  14. You are correct.
     
  15. Jack*Mains

    Jack*Mains Stunt Coordinator

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    Alright, so one last question:

    If I have a 142.5L sealed enclosure, do I just stuff it in there, or do I line the walls first and then stuff it?

    If porting the same box with the ESB allignment, do I want ANY polyfill in it at all, or just bare MDF?

    In both cases, how much polyfill would be required?

    Thanks a lot.
     

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