here's my new OB calculator :)

[hitsware]

http://home.comcast.net/~jhyamamoto/3ob3.xls

[Dave Jones]

Originally posted by hitsware
http://home.comcast.net/~jhyamamoto/3ob3.xls

Care to give us a hint as to what it does?

[hitsware]

Originally posted by Dave Jones



Care to give us a hint as to what it does?

After determining Fc (the freqency of the first order HP filter imposed by the baffle) one can take a chosen driver and (with a sealed box calculator (put the driver in an infinite baffle)), add the filter and thus approximate the system response.................

[markp]

A little more explaination would help. What are the columns and what is dia of?

[hitsware]

Originally posted by markp
A little more explaination would help. What are the columns and what is dia of?

space/1=in a tree
space/2=on the ground
space/4=on the ground near a wall
space/8=on the ground near a corner

height and width are the dimensions of a rectangular baffle
diameter is the diameter of a circle with the same area as the rectangle.................

[Kittle]

What measurement units are you using?
inches? feet? cm? meters?

[hitsware]

Originally posted by Kittle
What measurement units are you using?
inches? feet? cm? meters?

feet

[markp]

I think that there is more to it than that. The baffle can't just be converted to a round surface of uniform radius. The long axis will support lower freqs than the short axis etc....

[hitsware]

Originally posted by markp
I think that there is more to it than that. The baffle can't just be converted to a round surface of uniform radius. The long axis will support lower freqs than the short axis etc....

Intuitively I agree. However I have gleaned this approach from people who's knowledge I trust. Also it seems to be (empirically)
usable (within limits). A safer method would perhaps be to use the shortest dimension only (but perhaps too safe). This is in fact the same formula used to size the mouth of a horn. Obviously a mouth 1' x 9' is not going to act like a mouth 3' x 3', but perhaps if the ratio is kept reasonable all is well...........

[Gregm]

At the Fb calculation you have a constant "565". How do you get that?

I'm trying to convert the functions into metres/centimetres