15" Tumult or 15" Brahma? Which one for Home theater

Discussion in 'Archived Threads 2001-2004' started by Ben_E, Dec 2, 2002.

  1. Ben_E

    Ben_E Stunt Coordinator

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    Hello everyone. Well here I am thinking I had finalized my plan for my DIY subwoofer but of course I had to be stupid and look at more expensive woofers, was set on a Stryke AV15 and still kinda am but was curious as what your opinions would be on the 15" Brahma and 15" Tumult. If I decided to get either of these are they worth the price increase? The Tumult is $500 and the Brahma is $429, while the stryke av 15 is $205. Also wondering which one (Tumult or Brahma) is better for home theater. Any feedback would be much appreciated.

    Ben
     
  2. Seth_L

    Seth_L Screenwriter

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    How big of a box can you tolerate? If you can deal with a really large box 2 AV15 will beat the Tumult and the Brahma in SPL. Of course the Tumult would have a much smaller box (I'm not sure about the Brahma off the top of my head).

    Seth
     
  3. Ben_E

    Ben_E Stunt Coordinator

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    Well I was thinking about a 142L box for any of them, I'd like to shoot for around a 15 hz tuning point. How large of a box would be required for 2 AV15s? And what exactly does the tuning have in effect to everything else? Mainly I'm wondering if accuracy is sacrificed the lower the tune goes. But I'd probably want to stick to a single woofer as I don't really want to buy 2 amps. And thanks Seth for the reply.
    Ben
    Keep in mind too that I'm very new to this DIY stuff and still learning [​IMG].
     
  4. Seth_L

    Seth_L Screenwriter

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    Ben,

    How much power do you have?

    Seth
     
  5. Scott Simonian

    Scott Simonian Screenwriter

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    The AV15s wont require as much power as the Brahma or Tumult. If you cant afford a kilowatt amp you might want to stick with the Stryke.

    It sounds like you are going for quality and not SPL in the HT, a lower tuning point will most likely lessen the chances of the accuratcy decreasing. Since group delay goes up around the tune point, having it so low into the spectrum will yield unnoticable changes in accuratcy.

    My AA Tempest has a tuning of 15hz. I love it! It goes down deeper than any other sub Ive ever heard and tight as hell!

    Let us know about your amplification needs and what kind of sound character you would like.
     
  6. Ben_E

    Ben_E Stunt Coordinator

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    Ah power consideration. Well its either a 350 watt @ 4 ohm plate amp, but I have been thinking about the HS 500 (720 watts @ 4 ohms). Wow Scott I didn't know the lower tuning point would have the pretty much opposite effect than what I first though. And what did you mean by "what kind of sound character"?
     
  7. Seth_L

    Seth_L Screenwriter

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    Here are some sims I ran. 500W, 142L, Fb 15Hz. Keep in mind the ports aren't really managable in any of the cases.
    [​IMG]
    [​IMG]
    [​IMG]
    Seth
     
  8. Ben_E

    Ben_E Stunt Coordinator

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    Hey Seth thanks a bunch man. Those graphs definitely help me get a better idea. What did you use to generate those? I was messing around with WinISD earlier to get some ideas. It seems to me that the Tumult is not worth the extra $300, think that would be better used for a new receiver that I need after this sub. Noticed the more weight I add to the PRs the lower the tuning goes. A 1600 g 18" PR would give me just a hair under a 15hz tuning point, while a 2500 g 18" PR would give me a little over 12hz tuning point. What are the disadvantages of having a lower tuning point other than the pretty small sacrifice in DBs at higher hz? And would you recommend the 15hz or 12hz tuning?
     
  9. Mark Seaton

    Mark Seaton Supporting Actor

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    What readers should note in the above plots is that the Tumult actually produces the most output for the same given input power at very low frequencies. If SPL is the primary goal, an AV15 might be better with a little higher tuning and/or different box. My suggestion would be for the Tumult with a pair of heavily loaded 18" Stryke PRs.
     
  10. Seth_L

    Seth_L Screenwriter

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    I generated them with Unibox 4.02. I think you'll need more than 1 PR, but I have to run some numbers first.

    Seth
     
  11. Seth_L

    Seth_L Screenwriter

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    1 PR will be be sufficient for a 500W Tumult (IMHO).
    2 18" Styke PR's maxed out at 3kg each in a 142L enclosure give the following response.
    [​IMG]
    I think this is the best response yet but I'd move Fb higher to 18Hz. I also think the tumult should get more than 500W too.
    Seth
     
  12. Ben_E

    Ben_E Stunt Coordinator

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    I'll probably go with the AV15 since its price point is most appealing. But I'm not sure if I want 1 PR or 2 PRs. Would I want to stick to 1600 g PRs for the higher tuning or 2500 for a lower tuning? And again guys thanks for all your input.

    Ben
     
  13. Shawn Solar

    Shawn Solar Supporting Actor

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    The reason to use two pr's is not to tune lower, but, to lower distortion that could occour by exeeding the limits of the pr. Much like by generating less port noise you need two larger ports instead of one. Now when you double up on pr's the mass needed to achieve the same tuning point(in your case 18hz) doubles. the same goes for ports the length of each port doubles(roughly) that as a single port to maintain the same tuning point.

    The ports needed to properly tune the subwoofer and maintain low port noise just would not fit in the box.
     
  14. Seth_L

    Seth_L Screenwriter

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    That and you probably don't want the box to walk around the room.

    Seth
     
  15. heck, I have an enclosure that is about 45lbs and a driver that weighs about 40lbs. ..and this thing still moves the enclosure a little (no rubber feet yet)..and we are only talking about 220g of moving mass! I don't want to imagine what 2kg would be like!!!!!
    [​IMG]
     
  16. Ben_E

    Ben_E Stunt Coordinator

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    So would I be better off going with 2 1600 gram PRs or 2 2500 gram PRs?
     
  17. Shawn Solar

    Shawn Solar Supporting Actor

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    If you go with the 2-2500gram PRs it would tune the enclosure a lot lower. I would go with them.
     

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