The SW tools provided on this page are free and offered on an as-is basis. 

MMM Toolbox

The Mode Matching Method (MMM) Toolbox is now available for both Matlab and Octave. It enables you to simulate axisymmetric horns terminated in an infinite baffle, with accuracy approaching BEM, but with higher speed. See my reports and the blog entry on modes in horns for details.

The toolbox has previously not worked with Octave, mainly due to differences in the numerical integration routines. I have not though too much about this until recently, but when I was contactec by Tobias not long ago, and he told me he had found a solution, I had a go at updating the toolbox. It turns out that Octave has been significantly expanded since my last attempt, and now is very similar to Matlab in many respects. Since the original toolbox also was from my early days of working with MMM, I have also updated it using some methods I learned during my PhD. 

The current version is only for axisymmetric horns. It includes two examples: 

MMM_Horndemo1 calculates the throat impedance, SPL and polar data for a horn. 

MMM_Horndemo2 calculates the sound field internally in a horn.

Based on these two examples, it should be possible to modify the code to suit your needs. 

Please contact me with bug reports. 

 Download the MMM Toolbox for axisymmetric horns

Latest version is 1.1. 

Examples

Below is an illustration of the results produced by the MMM Toolbox. This is from the MMM_Horndemo1 file, using 8 modes and 00 frequencies.

Below is an example of the sound field inside and in front of a tractrix horn at 1.5kHz using 24 modes, from the MMM_Horndemo2 file. The soundfield in front of the horn is calculated using the Rayleigh integral.