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Microphone Polar Plots

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Re: Microphone Polar Plots

PostPosted: Thu Feb 25, 2021 7:00 pm
by wireman
I gave up on excel for anything but the most basic chart as it was a neverending source of frustration.

The height of madness was when I wrote macros to turn a spreadsheet of agenda items and times for a multiday meeting into a graphical representation (a drawing).

Re: Microphone Polar Plots

PostPosted: Fri Feb 26, 2021 6:14 pm
by forumuser840717
I thought I was reasonably competent with Excel's charting functions until a few years ago when I came across Tatsuo Horiuchi!

This article about him has a couple of downloadable spreadsheet examples of his work.

Re: Microphone Polar Plots

PostPosted: Fri Feb 26, 2021 6:42 pm
by Martin Walker
forumuser840717 wrote:This article about him has a couple of downloadable spreadsheet examples of his work.

:shocked: :o :clap: :shock:

Wow - just wow that anyone would go to that mathematical amount of effort to create a picture. Most impressive!

Everyone's different I suppose.


Martin

Re: Microphone Polar Plots

PostPosted: Sat Feb 27, 2021 2:49 pm
by wireman
Hugh Robjohns wrote:The problem I have is that the underlying plot is linear (it's a modified doughnut chart) and I really need it to be log. .

I had a go at this in python using the standard equations from here:

http://richbreen.info/McGill_Paper/mic_pairs.html

What is not mentioned is that you need to plot the absolute values of the functions.

To get a standard dB plot presumably you don't need a real log scale in Excel, just plot 20 log_10(sens) which will be negative and no comparison is needed as all the equations have a peak of 1.0. This will mean cutting off the minimum value in the plot.

I want to try adding together two cardioid microphones next...

Re: Microphone Polar Plots

PostPosted: Sat Feb 27, 2021 2:54 pm
by blinddrew
wireman wrote:I had a go at this in python using the standard equations from here:
http://richbreen.info/McGill_Paper/mic_pairs.html
That's what I was trying to use.

wireman wrote:What is not mentioned is that you need to plot the absolute values of the functions.
This is obviously what broke me as I haven't got a clue what it means. :)
It's slightly worrying that about 25 years ago when I was at University this would all have made perfect sense. :?

Re: Microphone Polar Plots

PostPosted: Sat Feb 27, 2021 11:13 pm
by James Perrett
Well I've just set our lad a challenge - produce an interactive 3D rendering of the different microphone characteristics using Scratch. He's promised that I can post a link if he manages it.

Re: Microphone Polar Plots

PostPosted: Sun Feb 28, 2021 6:21 pm
by Mixedup
James Perrett wrote:Well I've just set our lad a challenge - produce an interactive 3D rendering of the different microphone characteristics using Scratch. He's promised that I can post a link if he manages it.

I started trying to do that in Blender a couple of months ago... and gave up fairly quickly!

I was hoping for something I could rotate to match the mic angles on a 2D photo and have the lighting similar to in the room. But it turned out to be way beyond my skills/experience!

Re: Microphone Polar Plots

PostPosted: Sun Feb 28, 2021 11:11 pm
by James Perrett
Mixedup wrote:
James Perrett wrote:Well I've just set our lad a challenge - produce an interactive 3D rendering of the different microphone characteristics using Scratch. He's promised that I can post a link if he manages it.

I started trying to do that in Blender a couple of months ago... and gave up fairly quickly!

It seems he's given up too - which surprises me because yesterday he was showing me a 3D sphere with a surrounding star cluster that he'd made where you could freely move the camera around and the 3D aspects really worked. He's very into learning about the code behind 3D rendering at the moment but it has to be at his own pace.