Bramha 10 for HTuse?

Discussion in 'Home Theater Projects' started by Dan KW, Aug 22, 2004.

  1. Dan KW

    Dan KW Agent

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    I have a brahma 10 left over from a previous install in my car. I was wondering if I could use this driver as a small HT sub. I'm kinda interested in seeing if a small high powered P.R. system is possible.

    Thanks for any help you guys give me.

    -Dan
     
  2. GrahamT

    GrahamT Supporting Actor

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    The Fs is a little high but it should still make a good ported or sealed HT sub. I wouldn't add PR's because for that money you could buy a HT driver like the Tempest and be further ahead. Maybe Adire can suggest a box for the Brahma in a HT room.
     
  3. Dan KW

    Dan KW Agent

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    The Adire website suggests a .75 cubic foot box tuned to 32hz. Is it not good to tune below the fs of a driver? I've seen lots of guys saying that they have tuned to 12-14 hz on drivers that have fs values a little higher. I figured I could get away with something a little lower than that.

    I'll email adire and see what they think.
     
  4. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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    For HT use, I'd try to go with a larger enclosure and still tune around 32hz. Try up to 1.5 cubes depending on how much power you have.
     
  5. Dan KW

    Dan KW Agent

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    I got an email back from adire and they told me to go with 1.25 tuned to 25hz. I'd need about 800 watts and a subsonic filter at 20hz. Sounds like that is going to be the alinment I use.

    I'd love to use a different driver but I just have this one laying around..... It needs a workout[​IMG]
     
  6. Greg Monfort

    Greg Monfort Supporting Actor

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    Mass load it. Adding 84g (~half of its calc'd Mms) changes the published specs to:

    Fs = 28.574Hz
    Qms = 5.3895
    Qes = 0.5512
    Qts = 0.5
    Vas is unchanged
    eff. falls ~3.5dB

    Now an EBS is ~1.34ft^3 net/17.5Hz and can theoretically handle ~3.2kW before exceeding Xmax, not too shabby for such a small sub. The downside is that the mass will need to be firmly attached, so while you can experiment using loaded clay at low power to find the exact amount of added mass required, you won't be able to convert it back once you settle on how the final added mass is attached, such as a plywood disc/metal washers/whatever epoxied to the diaphragm. Note that if a disc is used, the cavity must be packed with insulation.

    Maybe DW has done some experimentation he'll share.

    GM
     
  7. RichardHOS

    RichardHOS Second Unit

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    With that X-max and FS I'd be tempted to try a sealed Linkwitz-Transform design. Not going to give you the most output, but makes the best use of what the driver already is... a really potent displacement in a small size.
     
  8. Dan KW

    Dan KW Agent

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    sorry I disappeared for a few days...my modem busted and had to get a new one. I don't know much about mass loading a driver so I don't think I'd like to glue stuff to the driver. I like the linkwitz-transform idea. I may try that idea too. it seems a little more work because I don't know much about that config but I can do some research on it.

    My wife and I are looking for a house so I don't think my tiny mighty is gonna cut it anymore... I need more bass but and trying to be cheap about it. Thus the want to use the brahma
     
  9. DanWiggins

    DanWiggins Second Unit

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    Dan,

    Either the mass load approach that Greg mentions, or the LT approach works as well, too... Personally, I might be tempted to go with a small vented box (somewhere 1.5 cubic feet and smaller), tune low (under 25 Hz), and equalize the response. It should give you pretty good output to pretty deep frequencies.

    Adding mass as Greg suggests works too, and you don't need the EQ, but I think with the small Brahma 10 I'd get some EQ.

    HOWEVER, have you thought about a conversion to a Brahma 15? Runs ~$124 plus shipping. We'll put a new 15" basket on it, and recone the driver as well. Drop that in a 3 cubic foot sealed box with a bit of EQ (or LT) on it, and it'll really shake up your house!

    Dan Wiggins
    Adire Audio
     
  10. Rich Kraus

    Rich Kraus Stunt Coordinator

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    dan you never cease to supprise with this sort of offer.
     
  11. Scott Simonian

    Scott Simonian Screenwriter

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    Dan, I had no idea you offered this kind of deal. Or is this a one time thing?
     
  12. DanWiggins

    DanWiggins Second Unit

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    It's a regular thing - we don't push it, because in 99% of the cases there's never a desire to change. But a standard recone is $99, and we'll put a new 12 spoke 15" basket on it for $25. Typically happens in 2-3 days...

    Dan Wiggins
    Adire Audio
     
  13. Steven Kephart

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    BTW, another benifit of the recone is you get all the new Mark II soft part, and better cooling due to the vents in the new basket.

    Steven Kephart
    Adire Audio
     
  14. Dan KW

    Dan KW Agent

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    That's cool! I'd really like to go that route but money is a little tight right now. Maybe in a few months after we close on a house and all....Christmas present[​IMG]
     

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