Quote:
Originally Posted by Xenon  Hi Collo,
I follow you here:
but I can't build a half-panel N11 so easily. I noticed in the ripple tank image that a pair of N11s had a nice spectral spread. Anyway, I need to add an N11 into the picture:
#1 N23 N11 N23 N23 N11? but not:
#2 N23 N11 N11 N23 N23?
Because #2 is an easy build, where #1 has issues. Any thoughts on this? |
In that case, go old school and have a look at 3 N23's and one inverse (I23)
The depths are different, but if you go for the +2 design, you get the best mix. For your 135mm depth, your design frequency will be 1162hz
Whilst this gets the lowest design frequency, you give up any zero-depth wells, meaning there is no point in side-shifting.
The N23:
Data for One Dimensional QRD (Quadratic Residue) Diffuser
Custom N23 panel: Shifted down 2 depth units
Design frequency 1162 hz
Number of wells: 23
Deepest well in mm 129
Fin width in mm: 2.5
Width of wells in mm: 40
Ratios 2 3 6 11 18 4 15 5 20 14 10 8 8 10 14 20 5 15 4 18 11 6 3
Well depths in mm 12 19 38 70 115 25 96 32 128 90 64 51 51 64 90 128 32 96 25 115 70 38 19
Phase shift in degrees 31 46 93 172 281 62 234 78 313 219 156 125 125 156 219 313 78 234 62 281 172 93 46
LF cutoff frequency 581 hz HF cutoff 4300 hz
Panel width 977.5 mm
Minimum distance to seating position 1776mm (3 times wavelength of LF cutoff frequency)
The I23:
Data for One Dimensional QRD (Quadratic Residue) Diffuser
Custom Inverse N23 panel: Shifted up 2 depth units
Design frequency 1162 hz
Number of wells: 23
Deepest well in mm 135
Fin width in mm: 2.5
Width of wells in mm: 40
Ratios 21 20 17 12 5 19 8 18 3 9 13 15 15 13 9 3 18 8 19 5 12 17 20
Well depths in mm 135 128 109 77 32 122 51 115 19 57 83 96 96 83 57 19 115 51 122 32 77 109 128
Phase shift in degrees 328 313 266 187 78 297 125 281 46 140 203 234 234 203 140 46 281 125 297 78 187 266 313
LF cutoff frequency 581 hz HF cutoff 4300 hz
Panel width 977.5 mm
Minimum distance to seating position 1776mm (3 times wavelength of LF cutoff frequency)
Barker coding:
N23 N23 I23 N23