Calculating sealed box resonance (f3)

rickymac21
10+ year member

2loud4u
Ok so I'm still trying to design this 4th order but not before I completely understand everything first.

I found somewhere that to find the F3 of the sealed chamber (or any plain ol sealed box) is used by a simple formula....

[(vas/vb)+1)^2] x Fs .... Assuming both vas and vb are in liters, I should with a certain vb shoot for an F3 of 45 hz correct? Or could I shoot for a lower F3 in the sealed chamber since I want to tune my ported chamber @ 40hz to pound lows??

The problem I've been having is I do this equation with the woofers I plan on using (American bass TNT) and I keep getting an F3 that's EXTREMELY high.

Here's the math with a sealed box (vb) of 2.25 cubic ft (63.712 L)....

[(77.2/63.712)]+1}^2 = 4.89 ...... 4.89 x 32.2(fs)= 157

What am I missing here? An F3 of 157hz is just stupid and no matter what woofer I put into this equation comes out this way. I've changed box sizes as well.. Is it my equation?

I just want to know so i can put these 2 15's in the best possible box for the output I want (LOOOWWWS)....

Somebody help me out here. I'm trying to figure everything out myself but as you can see, I'm having troubles.

 
Activity
No one is currently typing a reply...
Old Thread: Please note, there have been no replies in this thread for over 3 years!
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.

About this thread

rickymac21

10+ year member
2loud4u
Thread starter
rickymac21
Joined
Location
washington,OH
Start date
Participants
Who Replied
Replies
1
Views
2,762
Last reply date
Last reply from
rickymac21
IMG_20260515_202650612_HDR.jpg

sherbanater

    May 15, 2026
  • 0
  • 0
IMG_20260515_202732887_HDR.jpg

sherbanater

    May 15, 2026
  • 0
  • 0

New threads

Top