PR questions and Tumult apps:

Discussion in 'Archived Threads 2001-2004' started by Chris Popovich, Oct 27, 2002.

  1. Chris Popovich

    Chris Popovich Stunt Coordinator

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    Hey all,

    I absolutely had to get a Tumult when I looked at the specs. As you read this, I'm probably still excitedly coming up with new alignments. I have a couple questions.

    I'm not sure if I want to try to make a vented or a PR enclosure. If I do make a vented, it'll be with a slot port, though that's undoubtable going to be a real PITA to make, heavy and hard to tune. Anyone out there planning on this? Or even a basic ported enclosure?

    When modeling PR possibilities, I'm not sure how to recalculate the parameters when adding the effects of additional mass. I use Bassbox 6 BTW.

    When I change the amount of mass, MMS, either the Fs or Cms need to change. I change the Fs.

    Now either the Qms or the Rms needs to change. And I don't know which. Help! I'm pretty solid on ported modeling, but I'mnot so sure about PRs, this would help tons. Also, any alternatives to the Stryke or Adire PR's?

    Thanks in advance!

    Chris
     
  2. Craig Woodhall

    Craig Woodhall Supporting Actor

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    Chris,

    im in the same boat.. I was gonna put it in a 8-9 ft^3 ported coffee table type enclosure.. Problem is the Tumult doesn't like large enclosures (at least with WinIsd).. Whenever I try an enclosure size big enough to fit a port, it has a huge hump down low and doesn't look good at all..

    So, this driver, IMHO will either need a small sealed Linkwitz'd box or a dual 18" PR'd box.. The design on Kyles page which is 100L tuned to 19hz or what Jack was talking about is 150L tuned to 16hz both look really good to me.

    I am new to PR's and not really sure how to model them, especially in WinIsd (not even sure if WinIsd does Pr's). I find Unibox a little confusing, so am just gonna go with a box that the guys would recommend.. I will then modify it a little till a get a curve that I like.. At that point, i will just get Kyle or John to weight my Pr's for my final size box..

    Looks like ported it out of the question, and I don't think I would like sealed since it is for 100% HT. Wish I would have gotten a LT when Anthony was builing them.

    I don't think there are any other PR choices, I think you would need 3 or 4 of the Adire 15's.. I would rather go with 2 of the dual spider heavy duty Stryke 18's and hope they could take the pounding..

    Craig
     
  3. John E Janowitz

    John E Janowitz Second Unit

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    Hi Chris,

    First change the Mms on the PR. Then recalculate the Fs. Then the Qms. Cms and Rms will always stay the same.

    FYI, in a 21" internal cube, like listed on Kyle's site, a pair of the 18"Pr's with 3000grams gives about 15Hz tuning.

    Shouldn't be any issue with the PR's holding up. They can displace about 9L each. I've used these with the UE15 for quite some time now, without any issues. When I tooled the surround, I allowed for a full 1/2" of gluing surface on the diaphram, and when gluing to the basket the surroung goes all the way to the edge of the basket lip, almost 3/4" gluing area. When gluing the spiders to the tube, I use some reinforcment rings to give much more gluing area instead of just gluing the spider edge to the tube. I use all the high quality glues that Lambda Acoustics does.

    John
     
  4. Craig Woodhall

    Craig Woodhall Supporting Actor

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    John,

    i sent you an email
     
  5. Chris Popovich

    Chris Popovich Stunt Coordinator

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    Thank you John. That helps a lot!

    Craig: Easy solution -dual Tumults!
     
  6. Craig Woodhall

    Craig Woodhall Supporting Actor

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    Hehe, I wish I could go duals. anyone else have any PR comments?
     
  7. Jack Gilvey

    Jack Gilvey Producer

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    Play with Unibox a little more, it really is simple once you use it a bit. WinISD Pro (alpha) does PRs also.
     
  8. Craig Woodhall

    Craig Woodhall Supporting Actor

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    Jack,

    that is the one im using (alpha).. I will try to play with Unibox a little more..
     
  9. Jack Gilvey

    Jack Gilvey Producer

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    WinISD Pro is pretty cool, although I haven't used it that much. If you have specific questions on Unibox, you can e-mail me and I'll see if I can answer them.
     
  10. Craig Woodhall

    Craig Woodhall Supporting Actor

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    thanks Jack, as always!
     
  11. John E Janowitz

    John E Janowitz Second Unit

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    For modeling PR's, BassBox is probably a little more accurate than Unibox or WinISD. In the past they didn't let you account for the compliance of the PR's, while BassBox does. Maybe they do now, I'm not positive.

    John
     
  12. Craig Woodhall

    Craig Woodhall Supporting Actor

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    John,
    i sent you an email about shipping the PR's but haven't received a response.. Please email me at [email protected]
    Craig
     
  13. John E Janowitz

    John E Janowitz Second Unit

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    Hi Craig,

    Sorry I didn't see the email. I just searched for it and found it. It was dated 10/22/2000 instead of 2002 so it went way back in my emails. I'll reply to it now.

    John
     

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