Hi Mårten,
I had already downloaded a copy - thanks.
Because I want to be able to specify the adaptor length as an input parameter value, it will probably be necessary for me to take a somewhat different approach to the problem
.Kind regards,
David
@ David
Has any of my backhanded arm twisting prompted a sudden urge to develop a application for folding horns?
There are a few opensource CAD packages out there that could take a set of Cartesian co-ordinates and work some magic with the right prompting.
It seems like Master Geigher has done most of the work at one time or the other.
Has any of my backhanded arm twisting prompted a sudden urge to develop a application for folding horns?
There are a few opensource CAD packages out there that could take a set of Cartesian co-ordinates and work some magic with the right prompting.
It seems like Master Geigher has done most of the work at one time or the other.
I will rework that one after I get the HR tutorial updated.
There seems to have been some confusion about it while I was gone. Unfortunately, it seems I didn't explain things explicitly enough though, as I can see several threads here and there with questions, and the responses the OP's received were a little off base with my intentions.
To be honest, it was just a quickie job, and there are a few finer points that were only mentioned in passing to help cut down on my ramblings, so that hopefully someone would actually read it all. Posts worth of things were summed up into a single sentence once or twice.
The images could also have been a bit better as well.
Stories of my demise were a bit premature it seems...
Still don't have a working auto folder huh? It is a very tough nut to crack.
How about something that imported an HR model, and let you manipulate it in real-time? Sort of like the old AutoCAD script, only a stand alone 2d/3d program in C# & OpenGL that was set up for real world build constraints, it could allow you to adjust the width on the fly, and adjust itself for acoustic path variances (as best as it can) with auto corners instead of manually rotating each section individually? You could also have exterior build restriction options. Once 2d was going you could add in 3d for bifurcation rather trivially if thought about during the initial class/interface build phase...
I must not start another project...
too much on plate...
Last edited:
Hi Mark,
Not in the slightest. There is absolutely no chance of that happening - see the last sentence in my post #5197
.The only thing that I may decide to do is to develop a simple throat adaptor design tool - but I first need to finish the project I am currently working on.
Kind regards,
David
Horn/Driver Adapter Geometry
Hi David,
At the connection points, not only should tangents match
tan(a) = y' = dy/dx,
but also radii of curvature
R = ((1 + y'^2)^(3/2))/y''.
These requirements may be satisfied (at both ends) by a Clothoid segment [1].
I have written a function in Excel/VBA for the required Fresnel Integrals based on Boersma's algorithm.
If there is interest I will publish it here.
Regards,
Bill
n.b., this curve makes a very good horn bend /fold as well.
Reference [1]
Hi David,
At the connection points, not only should tangents match
tan(a) = y' = dy/dx,
but also radii of curvature
R = ((1 + y'^2)^(3/2))/y''.
These requirements may be satisfied (at both ends) by a Clothoid segment [1].
I have written a function in Excel/VBA for the required Fresnel Integrals based on Boersma's algorithm.
If there is interest I will publish it here.
Regards,
Bill
n.b., this curve makes a very good horn bend /fold as well.
Reference [1]
Last edited:
David
A forum friend is building a pair of Tannoy Westminster Royals.
He wanted help simulating the front horn. So I did a Hornresp simulation for him. He did some measurements on the cabinet so I also had a go on the compound horn simulation. Just for fun.
I think I have much more use of three sections allocated to the bass horn. Now they are allocated to the front horn.
Here is my quick and dirty hornresp record.
A forum friend is building a pair of Tannoy Westminster Royals.
He wanted help simulating the front horn. So I did a Hornresp simulation for him. He did some measurements on the cabinet so I also had a go on the compound horn simulation. Just for fun.
I think I have much more use of three sections allocated to the bass horn. Now they are allocated to the front horn.
Here is my quick and dirty hornresp record.
?
Hi David,
Have you read BK's Maters Thesis?
http://daim.idi.ntnu.no/masteroppgaver/010/10257/masteroppgave.pdf
Regards,
Bill
Hi Mark,
Not in the slightest. There is absolutely no chance of that happening - see the last sentence in my post #5197
The only thing that I may decide to do is to develop a simple throat adaptor design tool - but I first need to finish the project I am currently working on.
Kind regards,
David
Hi David,
Have you read BK's Maters Thesis?
http://daim.idi.ntnu.no/masteroppgaver/010/10257/masteroppgave.pdf
Regards,
Bill
Hi Kees,
Hornresp simulates axisymmetric horns only. This is usually close enough, unless accurate directivity performance predictions are required.
Construction data to build a square tractrix horn can however be exported.
Kind regards,
David
Hi Mårten,
But your attached record still shows the front horn as having only one segment, even though up to three can be specified
.Kind regards,
David
Hi Bill,
Thanks for the information. It all looks rather complicated - I had in mind something much simpler
.My intention was to match the tangent angles only.
Kind regards,
David
Hi Bill,
Yes, thanks. If you check the Preface, you will see that I get an acknowledgement for doing so
.Kind regards,
David
Last First.
I only read the conclusions first.
Will study the rest in detail later.
I like the challenge of a compute-bound problem.
Regards,
Bill
Hi Bill,
Yes, thanks. If you check the Preface, you will see that I get an acknowledgement for doing so
Kind regards,
David
I only read the conclusions first.
Will study the rest in detail later.
I like the challenge of a compute-bound problem.
Regards,
Bill
Hi Bill,
Thanks for the information. It all looks rather complicated - I had in mind something much simpler
My intention was to match the tangent angles only.
Kind regards,
David
David,
The problem is that some horn profiles have declining curvature as the mouth is approached; for others, the opposite is true. The curve fitting in both instances is a lot simpler than you suppose. Right now I am helping my wife with her accounting business during the tax return preparation crunch. After April 15th., I will provide a program to do this.
Regards,
Bill