Adire LSP, flare radius?

Discussion in 'Archived Threads 2001-2004' started by Tony Richardson, Feb 8, 2001.

  1. Tony Richardson

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    I did a search on the flare radius needed in the Adire LSP but I could not find anything that gives me the info I need.
    What is the correct number to input here for a 4" port?
    Thanks
     
  2. Trenton McNeil

    Trenton McNeil Second Unit

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    I too am confused by this. Are we talking the radius of the curve of the flare itself? If so, how do you measure that? Is it a measure from the center of the port to the lip? That's a huge difference, and perhaps is affecting some funkiness I am encountering in LPScad....
    Dan, are you out there?
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  3. Greg Monfort

    Greg Monfort Supporting Actor

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    Yes, it's the radius of the flare. Assuming a constant flare rate (and I have no idea whether or not that's how they're made since I don't use them), measure the o.d.(outside diameter) of the tube, and the o.d. of the flare. Then:
    flare radius = (flare o.d.-tube o.d.)/2
    GM
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    Loud is beautiful, if it's clean
     
  4. Patrick Sun

    Patrick Sun Moderator
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    If that's the formula, then the flare radius for the 4" flared precision port is roughly (7-4)/2 = 1.5.
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    PatCave ; HT Pix ; Gear ; Sunosub I + III ; DVDs ; LDs
     
  5. Greg Monfort

    Greg Monfort Supporting Actor

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    Ugh! It's not a constant. It just dawned on me that the flare o.d would have to be 2x the tube o.d. for it to be constant. This one will have a >1.5" radius. I'm betting 2". There's a way to calculate it, but at the moment my mind's a blank. [​IMG]
    GM
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    Loud is beautiful, if it's clean
     
  6. Trenton McNeil

    Trenton McNeil Second Unit

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    I say, screw it! Big ports, and lots of em is the solution.
    Flare shmare. [​IMG]
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    I wish I had a dollar for every time I spent a dollar, because then, yahoo!,
    I'd have all my money back. -- Deep Thoughts, by Jack Handey
     
  7. Greg Monfort

    Greg Monfort Supporting Actor

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    Up to a point, I agree, but eventually you change it from a vented design to a TL, then to a stopped pipe. The TL will sound great on music, but be seriously lacking on special effects. The stopped pipe will be an organ pipe, i.e. one note.
    I once built a little BP with an 8" driver, but needed a bunch more LF emphasis than it could provide, so I swapped out the vent for an externally mounted 12" dia x 96" L sonotude. With a little resistive damping to broaden the vent's BW, it was a killer sub that could be hidden between the sofa/rear wall, or mounted to fire into a corner.
    WRT figuring the flare radius, I would set tuning as desired, and just use the formula provided with the flare kit to get the desired length.
    GM
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    Loud is beautiful, if it's clean
     
  8. Jack Gilvey

    Jack Gilvey Producer

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    Hmm, I still can't find a number to input into LSPCad's "flare radius" box. It does insist that the number be greater than half the port length, which,of course, would be greater as the number of ports increases. Which implies that one can't input this number as a constant (as GM pointed out),as you would need to when using,say, the Adire 4" kit.
    When working backwards, and inputting flare radius numbers to try to achieve the desired actual 6" max. diameter of the Adire kit, one would need to input a value or 200cm for a 24" port. The radius changes based on the ratio of length to max/min. diameter. (As one would expect,given the program's assumption of a flared port...see below).
    I don't think there's a way to accurately sim. the 4" port kit using this program.
    I think the problem stems from the fact that LPSCad's idea of a flared port is one in which the entire port is flared, beginning in the middle, and not just at the very ends, like the ones commonly used in these parts. This is what's pictured in the .pdf manual:
    http://content.communities.msn.com/i...&ID_Message=47
    When designing this kind of port, the numbers make sense.
     

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