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LE15-Thumper
03-23-2009, 11:28 AM
In this link:
http://www.jblpro.com/catalog/support/getfile.aspx?docid=887&doctype=3

On page 5 it talks about horn design and prototyping.

Quote: "Most other horn designs have surfaces that
change direction simultaneously in only two of the
three possible directions. When this is the case,
prototypes are easily fabricated by the “modelmaker”.
PT waveguide surfaces vary in all three directions
simultaneously."

What are the THREE different directions they are talking about ?

TIA

subwoof
03-23-2009, 02:48 PM
Height, width and depth.

LE15-Thumper
03-24-2009, 12:51 PM
Height, width and depth.

How does the depth vary ? Aren't these horns a fixed depth from front to back ? :dont-know

I understand how the width and height varies as the horn flares out.

Uncle Paul
03-24-2009, 02:11 PM
I think when they refer to the surfaces vary in all three directions at the same time it's because all surfaces are compound curves. Compare a 2370 for example to one of the PT waveguides.

Robh3606
03-24-2009, 04:13 PM
Here's what one looks like up close. You can see the compound curves.

Rob:)

subwoof
03-25-2009, 01:21 PM
remember Dy/Dx ?? add a third variable into it and it becomes too hairy for anything but a computed controlled router to follow.

I tried something cute with spring steel to make inside horn curves back in the early 80's and it was not fun. And that was ONE dimension at a time with a boatload of waste.

Paul is correct.

sub

LE15-Thumper
03-27-2009, 06:44 AM
Thanks guys !!