Sometimes it could happen that some requested parameters' values in the (drivers') "Edit parameters" menu of Vituix CAD are not published in the specifications.
But some of them can be calculated from those that are given.
I want to share a spreadsheet I made to cope with this problem. In it, I included a cell to introduce the value of Rc that is the (non-top-of-the-end) cables resistance and crossover components connected in series that affect the Qes driver’s value. You may choose Rc = 0 ohm if you want to preserve Qes as given in the specification sheet.
Also, many times happen that the diaphragm’s effective area value does not yield to that published for the driver’s diaphragm moving mass. Then I need to adjust it to get the value of published Mms.
Cells with yellow background are for input values.
I hope you find some help with it.
Cheers!
But some of them can be calculated from those that are given.
I want to share a spreadsheet I made to cope with this problem. In it, I included a cell to introduce the value of Rc that is the (non-top-of-the-end) cables resistance and crossover components connected in series that affect the Qes driver’s value. You may choose Rc = 0 ohm if you want to preserve Qes as given in the specification sheet.
Also, many times happen that the diaphragm’s effective area value does not yield to that published for the driver’s diaphragm moving mass. Then I need to adjust it to get the value of published Mms.
Cells with yellow background are for input values.
I hope you find some help with it.
Cheers!
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VituixCAD calculates missing parameters (value=0) prioritizing fundamental parameters. Fundamental parameters are recommended to be entered (note VAS and Q are not fundamental). For example parameters in yellow of P17PRY in the Excel file produces:
Small differences to other calculations could exist due to differences in c and/or roo.
VCAD requires some values in Pmax and Xmax for the graphs, but these don't have to be "facts".
So any extra excel sheet is not needed.
Small differences to other calculations could exist due to differences in c and/or roo.
VCAD requires some values in Pmax and Xmax for the graphs, but these don't have to be "facts".
So any extra excel sheet is not needed.
Understanding the math and creating a spread sheet is well respected regardless.
Nice work and exploration Hugo
With first use many people have difficulties or didnt like
the cross calculating / sum check in WinIsd
They dont even allow the driver to be saved with errors.
Over time it is a amazing function to understand T/S math
and blow holes in bad datasheets or straight lies.
Though slightly different in function I have noticed
VCAD also works rather well for cross calculation / finding sum errors
and rather nice extended models.
Nice work and exploration Hugo
With first use many people have difficulties or didnt like
the cross calculating / sum check in WinIsd
They dont even allow the driver to be saved with errors.
Over time it is a amazing function to understand T/S math
and blow holes in bad datasheets or straight lies.
Though slightly different in function I have noticed
VCAD also works rather well for cross calculation / finding sum errors
and rather nice extended models.
Member
Joined 2003
T/S parameters can vary due to many reasons - environmental conditions, measurement method, measurement amplitude, manufacturing tolerances, etc. It's commendable and useful to understand the parameter calculations, however I've never had a reason to adjust the measured results so they match a datasheet that was created for some "golden sample" and often under unknown measurement conditions. Purpose of measuring driver parameters individually is to throw away the datasheet. The only thing that matters is the comparison of software result to real world performance.
I use specification data only for the simulation, just to see what I can expect. Measured parameters are obligatory for the final design.
I did some corrections to the spreadsheet including that of not regarding Vas as a fundamental parameter. Now is calculated from Cms and Sd values, In turn, Cms value is obtained from ws =2*pi*fs and Mms.
In my previous message "mandatory" should be in place of "obligatory".
In my previous message "mandatory" should be in place of "obligatory".
There is a mistake in cell C17 of "Equivalent parameters_V2.xlsx". A calculated value must be instead of a data. Then, I made the correction and now I'm sending the new version (Equivalent parameters_V2b.xlsx) where I use the values Vance Dickason presents in Table 1 in his report of the Dayton Audio’s UMII10-22 Ultimax II 10” Subwoofer published at:
https://audioxpress.com/article/test-bench-dayton-audio-s-umii10-22-ultimax-ii-10-subwoofer
In Table 1, Mms is not included, but Vas it is. Then I used a tool of Excel, that in Spanish is named "Buscar objetivo" (Look for a target value), that allowed me to get the value of Vas, be means of changing values of Mms.
I apologize for sending the previous spreadsheet with such error.
Unfortunately, in last spreadsheet, maximum handling power and maximum travel of voice coil are wrong but that doesn't affect the calculated parameters. I' very sorry of this.
https://audioxpress.com/article/test-bench-dayton-audio-s-umii10-22-ultimax-ii-10-subwoofer
In Table 1, Mms is not included, but Vas it is. Then I used a tool of Excel, that in Spanish is named "Buscar objetivo" (Look for a target value), that allowed me to get the value of Vas, be means of changing values of Mms.
I apologize for sending the previous spreadsheet with such error.
Unfortunately, in last spreadsheet, maximum handling power and maximum travel of voice coil are wrong but that doesn't affect the calculated parameters. I' very sorry of this.
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Thank you again for your efforts. I am/was still using Claus' Driver param calculator but was happy to find a more complete sheet than I've made and something "friendlier" than the DPC for quick checks.