Direction needed with HUGE box and dual AV15's

Discussion in 'Home Theater Projects' started by Richard Little, Sep 6, 2003.

  1. Richard Little

    Richard Little Stunt Coordinator

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    I have 4 AV15's on the way, but only want to use 2 for this project. I want to build a ported box approximately 700L internal volume like Jame's Dual Tempest "THE BIG PIG"(If anybody knows how to get a hold of James, I'd really like to talk with him about his design) and HTF's Bryan Michael also has made one that does just about what I want my sub to do. I’m trying to use WinISD but am getting different results than Jame's ended up with (WinISD shows it to produce lower dB's and to build it with shorter ports). For the amp, I won't say cost is no issue but if it requires a certain price tag to do it right then I won't skimp. I would like to get down to 16hz or even lower while maintaining an output that could frighten small children and adult alike[​IMG] I have planed on using 3/4" MDF then laminating it (good/bad idea?) Like James' sub I think that the walls will need to be braced. This will be my first home build speaker of any type but really enjoy DIY projects. Any advice/direction would be greatly appreciated and thanks.
     
  2. Shawn Solar

    Shawn Solar Supporting Actor

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    With two av15's unibox shows 550l enclosure tuned to 17.5hz with two 6" flared ports(aeroports)@ 20inches long is just about 120db to 17hz. probably expect room gain to bump you up to 125db with 1000watt input. You are above port air speed at max output but with the flares this would be reduced. I have yet to make my sub chuff with anything but loud sinewaves at tuning. And I have clipped my amp trying.

    Your box is going to be huge no doubt. I would do 3/4 mdf with a lot of bracing. You could probably use plywood for internal braces to cut down weight but expect 400lbs plus.
     
  3. Eric Eash

    Eric Eash Second Unit

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    i am looking at doing the same thing. i love the thought of this huge sub in my living room. my wife won't know what hit her. give me an email and we can share ideas. my original plan is 2 AV15's powered by a samson pro amp @500watts each. also looking at the art equalizer from SVS. not sure on wood, ports, wiring, etc. should all come together slowly. also thinking about a gloss black finish instead of veneer. should be a little less headache me for being a novice carpenter.

    eric
     
  4. ThomasW

    ThomasW Cinematographer

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    Richard

    I think you can find James at [email protected]

    Eric

    Seriously consider a parametric EQ (Behringer DSP 1124P is a good low buck choice) instead of a 1/3rd octave graphic one. The parametric is a little more difficult to operate but it's much more flexible and will in most cases provide better results
     
  5. Eric Eash

    Eric Eash Second Unit

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    i new to the whole equalizer thing, so thanks for the recommendation. any good sites for the behringer eq? i'm looking at doing the same type sub except downfiring. having a little trouble with unibox right now. i wish i had a seasoned vet over my shoulder letting me know what to do and WHY!

    eric
     
  6. Shawn Solar

    Shawn Solar Supporting Actor

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    I second the parametric. I use the behringer dsp 1124p. It is a little hard at first but there are enough spreadsheets out there and tutorials to help it is not a problem after an hour or so. I experimented a lot at first with it and can pretty much set up my sub in 15 minutes from start to finish.
     
  7. Richard Little

    Richard Little Stunt Coordinator

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  8. PaulDF

    PaulDF Second Unit

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    Richard, for what its worth, even a 350L "Little Boy" is a huge mother box. When I built mine (single 360L), I didn't quite clue in as to how big the thing really was until I tried to move it. It almost killed me down a flight of stairs. The novelty of such a box is wearing off, and to be able to move it without hiring help or hurting anybody would be nice. (I'd love to try it outside). On the other hand, it is quite a topic between my friends, and best of all, I get away with using a smaller amp.
     
  9. michael-e

    michael-e Agent

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    the larger the box,the more bracing needed

    i would expect 25mm mdf - 3/4 inch? all round, + HEAPS of bracing
    eg horizontal braces on the longest dimension 40cm apart, etc

    check out this guys bracing on his 18

    double u double u double u dot geocities dot com slash adrian_mack slash homepage.H t m l



    when your talking 600L.you mite as well go basshorn!
    [​IMG] [​IMG] [​IMG]
    Cheers,
    Mike
     

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