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

1. ### Tony Richardson Agent

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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 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 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 Moderator 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 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.
GM
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Loud is beautiful, if it's clean

6. ### Trenton McNeil Second Unit

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I say, screw it! Big ports, and lots of em is the solution.
Flare shmare.
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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 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

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