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Xplisit Kontent
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Member # 10725

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Okay, i'm writing a program in C++ that will help me when building ported boxes. It's kind of like WinISD, but it's text only, and can do some other stuff. It is, of course, not as advanced in some areas...

Right now i'm trying to write the equation for port area, in terms of box volume, port length, and tuning frequency.

The equation, you've probably all seen from JL's website, is this. -

Basically, i need to solve for Av, but i can't. I keep getting negative numbers under the radical... Can anybody help me out? I would owe you more than you know.

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1995 Grand Am GT
Nakamichi CD-45z
Pair of Audiocontrol EQT's
Audiocontrol 4XS
Crossfire TEK100.2
Illusion Audio ND-6
Crossfire VR142
Image Dynamics CD1E V.2

Looking for the following:
Image Dynamics IDMAX 12"
Crossfire BMF1000d or VR1000d
Posts: 48 | From: Buffalo | Registered: Oct 2002  |  IP: Logged | Report this post to a Moderator
guitar maestro
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Av=[(0.823*k + sqrt(0.677329*k^2+4*k*Lv))/2]^2

where k=(Vb(2*pi*Fb)^2)/(1.84e8)

have fun with that c++ program.....send me a copy of it when you're done so i can check it out

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http://www.sounddomain.com/id/xr7_sport
Posts: 307 | From: laredo, tx, usa | Registered: Dec 2000  |  IP: Logged | Report this post to a Moderator
Xplisit Kontent
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Member # 10725

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Thank you, man!

Can i ask how you got pi in that equation?

It looks similar to some of the things i got... I'll plug it in today when i get to school (don't have it on this computer here) and let you know if it works. If so, i'll definitely send you a copy, hopefully it will be of some help.

--------------------
1995 Grand Am GT
Nakamichi CD-45z
Pair of Audiocontrol EQT's
Audiocontrol 4XS
Crossfire TEK100.2
Illusion Audio ND-6
Crossfire VR142
Image Dynamics CD1E V.2

Looking for the following:
Image Dynamics IDMAX 12"
Crossfire BMF1000d or VR1000d
Posts: 48 | From: Buffalo | Registered: Oct 2002  |  IP: Logged | Report this post to a Moderator
guitar maestro
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Member # 3508

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i just happen to remember that 0.159 is an approximation for 1/(2pi)

trust me it works......i checked it out before posting

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http://www.sounddomain.com/id/xr7_sport
Posts: 307 | From: laredo, tx, usa | Registered: Dec 2000  |  IP: Logged | Report this post to a Moderator
Xplisit Kontent
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Member # 10725

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I wasn't doubting you before, just thinking aloud.

I plugged it in at school today, and yes, it does work! I appreciate it very much. I still have more to add to the program, so it won't be done for a while still (maybe 2 weeks or so. I only get to work on it about an hour and a half a day.), but i'll send a copy your way when i've got a semi-completed program.

Thank you, once again!

--------------------
1995 Grand Am GT
Nakamichi CD-45z
Pair of Audiocontrol EQT's
Audiocontrol 4XS
Crossfire TEK100.2
Illusion Audio ND-6
Crossfire VR142
Image Dynamics CD1E V.2

Looking for the following:
Image Dynamics IDMAX 12"
Crossfire BMF1000d or VR1000d
Posts: 48 | From: Buffalo | Registered: Oct 2002  |  IP: Logged | Report this post to a Moderator
jnespappa
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Thanks guys. I had been using spreadsheets with dif. Av's to get the Fb I was looking for.

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2001 Tundra Access Cab
H/U: P1R
Front Stage: Focal Polyflex 165H
Front Stage Amp: PG 4150
Sub: 8W7
Sub Amp: Xtant 301a
Posts: 163 | From: Lafayette, LA | Registered: Feb 2003  |  IP: Logged | Report this post to a Moderator
guitar maestro
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Member # 3508

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no problem guys......all hail, The Maestro! hehe [Big Grin]

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http://www.sounddomain.com/id/xr7_sport
Posts: 307 | From: laredo, tx, usa | Registered: Dec 2000  |  IP: Logged | Report this post to a Moderator
   

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