Tumult & 18" PR base cube

Discussion in 'Home Theater Projects' started by Nat Ward, Nov 28, 2003.

  1. Nat Ward

    Nat Ward Agent

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    I'm trying to decide what shape to make my PR'd Tumult enclosure and was curious as to what size you guys made your base cube. Taking the tape measure to the back of the Tumult and PRs, then using AutoCAD it doesn't like like you can use much below 22.5" before the baskets start touching. I look around though and see people making 24" exterior cubes with 1.5" walls, so my measurements must be pretty conservative. What did you guys use with success? 21" base cube? Thanks.
    Nat Ward
     
  2. Vaughan Odendaal

    Vaughan Odendaal Second Unit

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    I think your projected enclosure size is too small.

    Sure, Tumults work well especially in small enclosures, but I think that you should aim a little bigger.

    Perhaps a 30-40" cube? I would use 1" thick MDF walls all around, and a 1.5-2" thick front baffle.Extensive bracing only helps from there.

    You are going to use two 18" PR's correct?

    Regards
     
  3. Nat Ward

    Nat Ward Agent

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    My phrasing might be a little goofy. I want to make an enclosure with an internal cube of 21"x21"x21" made with 3/4" MDF (external measurement of 22.5"x22.5"x22.5"), which should end up with about 5.4ft^3. I'm taking out 1ft^3 for the volume of my amp, tumult and 2 PRs, which should leave me with about 4.4ft^3. Tuned to about 19.5Hz the response looked pretty good in WinISD. My problem was that I didn't know if a 21" internal cube would give me enough room between the basket of the Tumult and the PRs. I threw it together last night and today will router the holes. I'll keep my fingers crossed. Thanks for the repsonse Vince.
    Nat Ward
     
  4. Kyle Richardson

    Kyle Richardson Screenwriter

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    4.4cu ft will work well for the Tumult.
    I'm not sure if you will run into interference between the driver and PR's though since I havent built one quite that small - It will be close.

    Make sure you have good bracing (which will be difficult with the tight quarters inside) if you are using 3/4" MDF.
     
  5. Nat Ward

    Nat Ward Agent

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    I didn't get to finish it up tonight. I glued the second layer on (final of 1.5") and got to router out the hole for the Tumult and about half way through the first hole for the PR before I lost enthusiasm. Don't get me wrong, this is a fun project, it just loses it's appeal when you're working in the cold outside in the gusty wind at night [​IMG]. I'm still scared of interferance, but I'll hope for the best. Thanks for the input Kyle, after going through all of this I'm somewhat surprised at the price ask for your 24" cubed flat box. Who woulda thunk that building a "simple" cube nicely would take this much time and effort?
     

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