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Microphone Polar Plots

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Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 12:38 pm
by Hugh Robjohns
I'm feeling decidedly chuffed that I managed to beat MS Excel into a grumbling submission and managed to get it to plot a complete set of first-order polar responses... so here, for your enjoyment and edification, is the plot -- (c)Hugh Robjohns 2021 !

Polar pattern plots.jpg

Re: Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 12:41 pm
by James Perrett
Very nice - but should there be some numbers on the attenuation scale?

Re: Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 1:04 pm
by Mike Stranks
Good work that man!

Take a bow! :clap: :thumbup:

Could you put this somewhere easy to find so that it's easy to retrieve when the next person comes along with a question about the polar sensitivities of different types of mic?

Re: Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 1:08 pm
by Hugh Robjohns
:D Picky, picky...

Erm... yes... possibly.... :crazy:

I haven't quite figured out yet how to get the underlying to scale to conform to anything useful. Excel really isn't the right tool for this job... and I'm pleased I managed to get it to go this far.

At the moment, those circles are at roughly 1.2dB increments... I'll have another fiddle later when I have some time.

And yes, Mike, I'll copy this to the useful info archive. Good idea.

Re: Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 1:18 pm
by James Perrett
Hugh Robjohns wrote::D Picky, picky...

I've got the wide cardioid Line Audio CM3's and I was just reading the chart and wondering what the front to back ratio should be with them when I realised that there was no scale.

It is amazing what you can do in Excel. I've just created a suite of macros to handle PRS statements for a friend of mine. They're not pretty and the job could probably be done better with a database but they seem to work. We also started off doing all our post mission data processing for Autosub in Excel before moving to Matlab. It is a great way to get started on something fairly quickly.

Re: Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 1:24 pm
by Zukan
Doing that in Excel makes you proper Jedi!

I'm still on 'text to columns'.

Re: Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 1:34 pm
by Hugh Robjohns
James Perrett wrote:I've got the wide cardioid Line Audio CM3's and I was just reading the chart and wondering what the front to back ratio should be with them when I realised that there was no scale.

Of course -- you're quite right.

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. Not found a way to do that yet without going to the whole faff of calculating and plotting the whole thing from scratch... But it will continue to be a thing I'll tinker with as and when... I quite like playing around in Excel!

The impetus for doing it in the first place was simply to illustrate the relative directivity and rear-tail sizes of the super- and hyper-cardioid paterns... and then I figured I should really add in the other standard patterns too...

Re: Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 2:01 pm
by ManFromGlass
Use bold
Then I can say the plot thickens . . . . . .
did I say that out loud? Inner voice, inner voice

Re: Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 2:11 pm
by Hugh Robjohns
Is this your coat? :lol:

Re: Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 2:20 pm
by ManFromGlass
Thanks. How did you know I had to go? :beamup:

Re: Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 3:14 pm
by blinddrew
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. Not found a way to do that yet without going to the whole faff of calculating and plotting the whole thing from scratch...
Hmm, I think I stumbled across this as an option a few years ago. Let me have a shufti.

Re: Microphone Polar Plots

PostPosted: Wed Feb 24, 2021 3:21 pm
by Zukan
ManFromGlass wrote:Use bold
Then I can say the plot thickens . . . . . .
did I say that out loud? Inner voice, inner voice
Image

Re: Microphone Polar Plots

PostPosted: Thu Feb 25, 2021 7:45 am
by blinddrew
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.
Excel will happily play with log scales on the axis, it's a tick box option on the right-click > Format Axis menu.

Hmm. I've got the axes working fine but I must be inputting my data wrong as Omni is ok, fig 8 looks like a reverse cardiod and everything else looks like a variant of a Hypo!

Re: Microphone Polar Plots

PostPosted: Thu Feb 25, 2021 12:46 pm
by jimjazzdad
It all looks a bit like a Psychedelic Shelob in her lair to me...what have I been smoking?

Re: Microphone Polar Plots

PostPosted: Thu Feb 25, 2021 12:49 pm
by Hugh Robjohns
blinddrew wrote:Hmm. I've got the axes working fine but I must be inputting my data wrong as Omni is ok, fig 8 looks like a reverse cardiod and everything else looks like a variant of a Hypo!

Yes, I was aware of the log scale option, but (a) it doesn't work with negative numbers and I have a four-quadrant (bipolar) plot here, and (b) it's geared up for linear XY plots rather than the radial one I've contrived by hacking the doughnut chart option....

Anyway... if I remove the grid the problem goes away, and the comparison of polar patterns becomes even clearer! :-D

Polar pattern plots no scale.png