2D inverse N7 panel - confused again

[Sebg]

Where is it "failing" on the scorecard?

[hally]

Hi Sebg,

here is a screen shot of the scorecard



thanks
hally

[localhost127]

it's not "failing"; it's an informational notice that there is only one true diffusion frequency due to HF cut-off limitation.

[hally]

Thanks localhost,

What does it mean

that there is only one true diffusion frequency due to HF cut-off limitation

Does it mean that the omniffusor does not diffuse an octave above and below the design frequency?

thanks
hally

[collo]

Originally Posted by hally

Hi to all the diffusion experts, i need your help again

I have spent the last couple of weeks trying to get a basic understanding of diffusion and the various modules that can be built to achieve my difuusion goals. To date I have sucessfully designed and built 9 of the skyline type diffussors, an array of N31 1D diffussers, 3 standard and 1 inverse. I have turned my attention now to trying to build a clone of the FRG omnifussor from RPG which i understand to be a 2D inverse N7 panel. I am having a great deal of trouble trying to understand and design this panel using qrdude...I have read as much as i can find about these 2d panels but still i'm lost

Reading material...
QRDude design change disccussion
QRD diffusers: Technical Overview
Omniffusor dimensions

In qrdude i am trying to duplicate the dimentions of the RPG omni, working from the cutlist published here,
http://www.rpginc.com/ProductDocs%5C...usor%20FRG.pdf

I estimate the well widths to be approx 76mm and the fins approx 6mm. The 2d build is said to be 102mm (4"). When i input these figures into qrdude i am failing on the scorecard. I know there is shifting and optimizing and other advanced stuff going on which i just don't get.





Can somebody please hold my hand and help me get my head around designing and building this omni, thanks

hally

You're so close - If you click the "No Shift" button on the 2D screen the whole pattern will move so that the zero depth well is at the left front position on the graphic, becoming recognisable as the diffuser you're trying to copy.

As far as the bandwith caution goes, this is a consequence of the ratio of the well width to design depth. Since these are meant to drop into a false ceiling grid, the ratio is pretty much determined. For better coverage, you could make them deeper.

regards,
Collo

[hally]

Thanks a million Collo, I was just a click away, here is the the panel shape with the no shift button on...



Let the carpentry begin...

I think I will increase the debth to 5" or 6" and decrease the well width a bit to increase the bandwidth a bit....

regards
hally

[collo]

Happy to help out mate! Good luck with the build.