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Introduction to Cubic residue diffusers

In former articles I explained some aspects of common QR-Diffusers known as Schröder-diffusers and CR-Diffusers. Here both equations are used overlaid to obtain a 2D-structure with is not symmetrical.



2D QRD/CRD - Sound Treatment


2D acoustic diffusers using qrd and crd equations 

An optimized 2D-residue diffuser using quadratic and cubic equations. Here 23 wells per period are used to obtain a fully symmetrical behavior.

 

0 0 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
22 11 0 12 9 22 13 13 7 3 9 10 14 6 17 9 13 14 20 16 10 10 1 14
QRD 21 12 6 21 19 8 19 14 1 11 6 17 6 4 19 13 17 16 18 8 17 7 9 8
Y 7 20 2 13 20 8 8 5 7 22 12 8 18 4 20 5 13 6 15 2 21 11 3 5 2
X 19 19 1 18 6 19 19 14 12 21 3 12 10 5 5 18 6 0 8 15 6 12 18 9 16
18 6 18 22 3 15 20 3 18 4 15 13 6 2 9 12 19 15 8 6 17 3 18 1
CRD 17 14 10 19 3 16 20 0 10 12 14 1 4 8 21 5 14 10 1 18 0 1 6 0
Y 13 16 22 14 17 16 19 11 0 17 1 6 17 19 20 5 5 5 13 14 16 4 9 16 10
X 17 15 4 4 13 16 21 13 0 13 14 11 12 2 12 4 9 12 21 21 20 3 1 22 5
14 3 0 4 0 19 0 20 18 2 3 6 19 4 15 14 9 8 19 4 17 20 21 5
MOD 13 16 22 10 11 10 15 11 6 8 2 19 21 16 12 17 16 17 5 11 20 17 10 7
23 12 17 21 5 0 14 9 16 20 6 5 2 5 22 15 15 7 22 22 15 9 12 9 8
11 3 17 9 10 5 2 9 11 16 9 21 14 19 21 5 2 20 21 13 4 2 15 5
10 17 7 19 15 3 14 10 22 12 11 4 22 4 4 7 21 8 22 2 2 7 2 18
9 10 11 9 12 5 19 16 4 14 8 17 3 20 7 18 15 6 22 2 0 1 13 21
8 2 3 22 21 8 14 1 0 19 20 11 0 18 4 12 4 11 18 10 18 4 22 11
7 13 3 9 16 9 19 8 7 1 21 6 10 18 15 9 8 20 7 0 7 13 3 8
6 17 8 13 17 5 8 11 22 3 8 22 7 17 14 6 1 7 9 15 10 2 22 9
5 11 15 8 21 16 1 7 19 22 1 10 11 12 21 0 3 15 21 6 1 14 7 11
4 15 21 14 2 16 18 16 18 9 20 13 19 0 10 11 11 18 17 16 0 0 1 11
3 3 0 5 3 2 10 12 16 7 16 5 5 1 1 13 22 13 17 19 4 3 1 6
2 18 18 1 21 17 20 15 10 13 9 6 12 12 14 3 10 20 18 12 10 20 4 16
1 11 3 22 7 12 22 22 20 1 19 13 14 7 0 1 18 13 17 15 15 2 7 15
0 2 21 19 4 7 13 7 20 14 20 0 8 6 2 4 20 12 11 2 16 15 7 0

Values taken from the Excel

 

 

Conclusion and Summary

 Optimized residue equations can be used to obtain a non symmetrical 2D-diffuser.

 

 See the former article about QRD-diffusers

 

 You may also want to have a look at this Multi Frequency Diffuser  

 

 

© 2007 J.S.