Stuff your sub!

Discussion in 'Archived Threads 2001-2004' started by Nathan_M, Apr 22, 2002.

  1. Nathan_M

    Nathan_M Extra

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    [Edit: In my original post I was a little over-exuberant about my performance gains by stuffing my sub. [​IMG] I just wanted to edit this to say that despite my gains that each situation is different and you should take into account your room size, box design, driver specs and performance goals to see if stuffing will improve your performance like it did mine.]
    After reading Ron-P's thread on the difference adequate stuffing makes, I tried stuffing my sealed sub properly this weekend. What I thought were giant room induced humps have almost been completely tamed.
    I built a 1.75^3 ft. sealed enclosure for a DVC 12" driver with a 250 PE amp powering it. I built the enclosure a little larger than some folks had because I was not interested in getting any sort of bumps in the response (didn't want a Q greater than .7). So I built it a little larger and lined the walls with egg crate foam thinking that would be enough stuffing with such a (relatively for the DVC) large enclosure. But when I tested it using AVIA sweeps I had a huge hump in the response between 45 and 55 HZ. This made it very hard to calibrate and it did not sound so great. All bass in the 60-80 and 30-40 region was essentially not heard because if I calibrated based on the levels in those regions, any sounds in the hump were overpowering and so the sub level was always too low in some regions and too loud in others. But I wrote it off to "room induced humps" that I'd read about.
    Well, I read Ron-P's thread and decided to really stuff the crap out of it and see what happened. Holy hell, does this thing rock. Hump is almost all gone (I may stuff it even more). I now have it calibrated properly and my music and movies sound "right" again. By the way, you guys with Tempests seriously need to check your hearing and wear ear plugs or you're going to go deaf because the amount of clean bass that this little sealed 12" DVC can put out with the amp gain set 2/3's of the way up is rattling my hole dang townhome. Please be careful. I have tinnitus and when I think of what a ported Tempest might be doing to yall's hearing it makes me worried.
    So the lesson I learned and want to pass on, especially if you're like me and are following the suggested designs of others, is that if those designs contemplate stuffing, don't skip that part.
    Thanks Ron-P for posting!
     
  2. Ron-P

    Ron-P Producer

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    Your welcome Nathan. Glad to hear it worked. It REALLY makes the difference. I ended up with 6.5lbs. in my 177L sealed sub. The sound is nothing short of perfect. Even at very low levels, the bass is...excellent. It blends prefectly with the rest of the speakers and accents them, something I could not get my Velodyne to do.
    I had some friends over Friday night and we pulled a double feature, plus we ran thru the Fox Demo disk #1. Everyone said how hard and clean the bass was and also how much the bass improved the rest of the sound thru out the room.
    Peace Out~[​IMG]
     
  3. Scott Parker

    Scott Parker Agent

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    I think I may need some more stuffing then. I put 5 lbs. of poly-fill in my 340 liter enclosure and it helped a little but not a whole lot. It still kinda has that overhang sound to it. I'll play around with placement some more too, cause I am getting about +10db around 50hz or so.
     
  4. Ron-P

    Ron-P Producer

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    Scott, I was getting the same, a 10+db peak at 40-45Hz, the additional polyfill completely did away with it. I have an extremely flat response across the board now. If I am at 6.5lbs for 177, I'd say you need more.
    Is your sub sealed or ported?
    Peace Out~[​IMG]
     
  5. Rudy H

    Rudy H Stunt Coordinator

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    In a low Q sealed box, stuffing will reduce the amount of bass your sub puts out in the ~30-60hz region, so it may be helpful to some (namely those with small rooms), but it may hurt other's performance.
     
  6. Nathan_M

    Nathan_M Extra

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    Good point Rudy. Sorry to make generalizations. I guess what I should say is experiment with stuffing if you're having the same problems as I did.
     
  7. Jeffrey Noel

    Jeffrey Noel Screenwriter

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    How about adding stuffing to a PR enclosure? Mine sounds pretty good now, but could it sound any better? I've never really heard anyone stuffing a PR'ed enclosure but never hurts to ask! [​IMG]
     
  8. ThomasW

    ThomasW Cinematographer

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    Jeffery

    My experience is that PR designs do better simply being lined.

    But some have reported improvements with added stuffing.

    So experiment.....
     
  9. Brian_E

    Brian_E Auditioning

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    Those of you interested in learning more about how stuffing a box with fiberfill can effect performance should check out the following url (if you haven't already).
    http://integra.cyberglobe.net/caraud...ces/fiberfill/
    I believe this link was posted to this forum several months ago and it helped me understand how SVS got such a low Fb out of their subs WRT their actual volume and port size.
     
  10. Daniel T

    Daniel T Stunt Coordinator

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    I have an infinity BU-2 downfiring sub. If I was to stuff this sub do you have to keep the stuffing away from the driver or does it matter? I found it boomy until I calibrated it but if I can get better bass from it by just adding stuffing I could hold off build a sub for a while. If anyone can tell me what is the best way to stuff a downfiring sub I would appreciate it. Thanks.

    Daniel T
     
  11. Robert_Gaither

    Robert_Gaither Screenwriter

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    Daniel, some of the pillow case stuffing (at least the cheap ones I bought at Walmart about 2 years ago) were folded in a roll somewhat (don't know how else to describe it but it wasn't a round roll) that you can spread somewhat behind the driver and should not fall in between the woofer cone and basket.
     

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