how to go from horn response to a folded bass horn design?

[paulspencer]

I have a few Q's about going from a bass horn "design" with some numbers and charts in horn response ... to a design that can be built.

Does anyone have forumulas for the different contours?

Has anyone tried a folded horn where there are no parallel sides? (tricky yes)

Suppose I wanted to stack a number of horns to make up the required horn mouth area. How close do the mouths need to be in order to couple? 1/4 WL apart?

Is it better to stack smallish horns, with the necessary length, small 8" drivers and making up the combined mouth size ... or a single larger horn with a bigger driver?

[slowmotion]

Hi

Originally posted by paulspencer
I have a few Q's about going from a bass horn "design" with some numbers and charts in horn response ... to a design that can be built.
Does anyone have forumulas for the different contours?

You allready have that function in Hornrespons;

When you have calculated your horn, go to "Window",
then "Schematic Diagram" . When in "Schematic Diagram"
go to "Tools" and point to "Export". A txt-file will then be made
with the horn contour. You will it find in the Hornresponse
folder under "export".

Several spreadsheets can be downloaded from the web,
but we've talked about that in an earlier thread,
so I'm sure you've checked those out allready

cheers

[mike.e]

I do it in CAD,starting at the mouth,going 'x' distance in depth,and following the expansion around,approximating it as parabolic/conical sections.

[paulspencer]

How do you approximate the curve to straight line segments? What kind of resolution?

[Centauri]

Paul,

I would think you have probably seen this, but in case you haven't, or lost link etc, this page describes how I do it (using Autocad, but the same principals can be used manually). The spreadsheet there may also be of use.

Cheers
Graeme

[mike.e]

My horns are 2Das its easier to make,and Qcad 1.5 only does 2D as far as I know.
My method is fast once you know it.

Graemes method is fancy and good but I dont have autocad2002 nor want to relearn it,it was most un intuitive and slow.

I draw a straight line from the mouth to the point at which the corner begins. This forms a parabolic expansion. Then I estimate that the path length is formed at 1/2 the corner radius,and the area will decrease as the horn turns the corner. Then I might put a corner reflector in,or not if its only a 2 or 3 octave basshorn.

And carry on,with whatever folding scheme. It works for bass. Basshorns sound funny when folded so theres no real worrys about trying to make perfect corners,just keeping the area approximatly correct is enough.

[paulspencer]

Graeme, I haven't seen that link, thanks.

[slowmotion]

Hi

Very nice post by Tom Danley here:

http://www.audioasylum.com/forums/hu...ges/96159.html



cheers

[mike.e]

http://www.geocities.com/xobt/TD.rtf
http://www.diyaudio.com/wiki/index.php?page=Bass+Horns