Excellent, thank you. It's often hard to know what is going on when things aren't defined. So j here is really i as in imaginary number, not some speaker related parameter. And i is basically the square root of -1. So I would potentially just calculate in this, in correct order of operation.
I'll test things out.
Thank you, this clarifies things so much. 🙏
Edit: oof, having a hard time getting LibreOffice and a normal calculator to like this....
Very best,
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You need to use complex number functions: https://wiki.openoffice.org/wiki/Documentation/How_Tos/Calc:_Complex_Number_functions
Using Excel:
Using Excel:
Thanks, trying a few things then...
Looks like I'm using it incorrectly... will work more on this. Any help appreciated!
The author of the excel that does this from the class I took straight up won't share and says they can't remember, so I'm guessing they didn't actually create it and just copied it and didn't understand. Sadly. So I'm on my own again. Any help is super appreciated!
Very best,
I woke up way too early this morning so I had some time to kill. I’m not a regular Excel user, but cobbled together this program from another one. I used Excel, but it opens in Open Office (although the chart looks a bit different). It doesn't use macros, but I saved it as a .xlsm file to upload it.
While I applaud your desire to know the math behind the scene, I do feel your time would be better spent understanding on a more intuitive basis. To fully understand the math behind acoustics requires a thorough understanding of calculus including differential and integral equations. That's just the way it is.
While I applaud your desire to know the math behind the scene, I do feel your time would be better spent understanding on a more intuitive basis. To fully understand the math behind acoustics requires a thorough understanding of calculus including differential and integral equations. That's just the way it is.
THANK YOU SO MUCH!!
I certainly don't know what I don't know. That's for sure. I figured there has to be an easier way to do this without a lifetime of study. Others are using it in software and in sheets but can't explain it like they're 5 years old.
Just seeing the way you entered the math into the spreadsheet helps a TON to understand its use. Seeing an equation is one thing, but using it is another. And to complicate it, using it as a language in a calculator that requires specific syntax and order. So this is very helpful. It opened no problem in LibreOffice (OpenOffice successor).
I will take time to study this. Thanks again! Ultra helpful. A++++
Very best,
No worries, I was able to follow the math in the cell formula boxes and where they reference and it all made sense. Thanks again, this is super helpful! I understand the math now that the imaginary number part's implementation is sorted. I just didn't know how to use that in spreadsheets to properly calculate things with commands and obviously doesn't just work on a basic calculator. The rest is not difficult to understand. This part is what had me all hanged up. Your commands for its use both absolute and for imaginary in the calc sheets cleared up the mud for me big time. Thanks again, super super helpful!
++++++++++++++++++++++++++++++
Understanding this better, I can now compare two things that I want, just to test methodology and derivation....
Near field and corrected to full space with this derivation method vs ground plane 1 meter method and compare the response shape. Either can be used, but I'm curious if they will be in agreement within 1db or similar, and so that's two methods depending on my weather and if I can do it inside when its raining, this will be very helpful.
Very best,
Just checking some work, I'm not sure why order of operations is resulting in two separate outcomes, but maybe I found the reason. Just wanted to confirm:
f0=34.16/(E10/(E11/E10)^(1/3))
It looks like here we're doing 34.16 / w / (h/w) ^ (1/3)
But that's w divided by h/w^1/3.
I guess I'm confused here simply because in the other proportion, it's showing it as w(h/w)^(1/3):
Is this correct, or should it be divided as you have?
My result for example with your input height and width is 149.207 instead of 195.517, but I think its entirely dependent on the multiplication vs division there of the width as shown.
Or is the division there due to the fraction exponent and that's my oops?
Very best,
No worries, thanks! I just wanted to make sure I wasn't making a mistake there. That solves everything for me and I'm able to move forward.
Thanks again, so very helpful! 🙏
Very best,
Thanks, it's all sorted out now and working. I just didn't know how to correctly use it in spreadsheets to do the calculations. Now it's done, I have a tool made, and I can compare the corrected response from a near field measurement to a ground plane soon I hope to see how close they are.
Very best,
I drafted up a sheet based on the help. The goal will be to have a calculator that I can take my measured near field FRD and copy & past them into an open cell field. Then give baffle dimensions. Then the sheet will produce the corrected full space SPL that I can then re-save as the corrected FRD. So far, the equations are working, the cells are working, the first line at 20hz is working correctly. Happy!
Very best,
Very best,