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Old 4th April 2005, 06:25 AM   #1
jim_vt is offline jim_vt  United States
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Default Help calculating box dimensions & port

Hi -

This is taxing my brain this late at night, trying to figure all of this out...

I'm going to use two Fostex 127E's in a BR enclosure. Fostex gives a spec of 10 liters tuned to 71Hz for one driver...so I need a 20L enclosure for both, but I'm having trouble figuring out dimensions and port calculations.

Click the image to open in full size.

That's pretty much where I'm stuck



Thanks for any help in advance...
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Old 4th April 2005, 07:48 AM   #2
jim_vt is offline jim_vt  United States
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sat down and did the math, came up with this:

Click the image to open in full size.

Looks good? it's almost 3AM EDT here so my math might be completely off...would be worth a double check.
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Old 4th April 2005, 08:42 AM   #3
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The best and simplest way would be just to add a shelft inbetween the two boxes so that each one is just the same volume as the intended original design. This would also add stiffening to your box which is always a good idea.

If you want to play with vent sizes I have a little (basic) utility called vent designer on my website in the utilities section.
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Old 4th April 2005, 12:40 PM   #4
K-amps is offline K-amps  United States
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Richie whats your website
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Old 4th April 2005, 01:09 PM   #5
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Old 4th April 2005, 01:14 PM   #6
K-amps is offline K-amps  United States
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OK how do I delete the last 2 posts.
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Old 5th April 2005, 05:08 AM   #7
TerryO is offline TerryO  United States
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If you're doubling the internal volume, you can be lazy and just use two ports with the same internal volume as the single. There are other ways to do the vent as you're already attempting, but this will certainly work. Unless the original port is undersized, then two of them shouldn't be a problem. If you add a shelf brace just remember to allow additional internal volume to compensate for the displacement of the brace.
Sounds like an exciting project, good luck!
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