@Sandasnickaren ...Nifty lot you've got there....happy to see the interest using non-trad materials and 'tuning' to overcome 'cone honk' and tuning it to a useful waveform into a cylindrical cavity....
3D printing makes the complex easier to fab, at least....something on my wish-list, nearly affordable but no place to place it...sigh
Looks like a C/F cone, noting the arcs of the texture appears to be a fabric...how did the seam work out?
Ti and aluminum I can get predicable cones with a minimum seam, size limited by sheet width.
My large cone I've been crafting is nom. 21mm dia., top is 142 mm dia., and 222 mm tall @ the centerline of both T & B. The tricky bit was to formulate a means of rolling a cone sans a dinky but accurate slip roll.....
THAT I've room for....but my jerryrigged version works well enough for now....🤞👍😏
Anyway, the KEF 'coin' sounds like something I've not seen nor heard of.....any chancel of a look at one?
Too many questions.....y'all had more free-time than I....
...which is a Good Thing, at the end of any other day.... 😉
Cheers, J
3D printing makes the complex easier to fab, at least....something on my wish-list, nearly affordable but no place to place it...sigh
Looks like a C/F cone, noting the arcs of the texture appears to be a fabric...how did the seam work out?
Ti and aluminum I can get predicable cones with a minimum seam, size limited by sheet width.
My large cone I've been crafting is nom. 21mm dia., top is 142 mm dia., and 222 mm tall @ the centerline of both T & B. The tricky bit was to formulate a means of rolling a cone sans a dinky but accurate slip roll.....
THAT I've room for....but my jerryrigged version works well enough for now....🤞👍😏
Anyway, the KEF 'coin' sounds like something I've not seen nor heard of.....any chancel of a look at one?
Too many questions.....y'all had more free-time than I....
...which is a Good Thing, at the end of any other day.... 😉
Cheers, J
Hi,
They are created one by one. The longest tube is 567mm so it’s bent two times in order to make the whole metamaterial reasonable in size.
I can send the file if you are intrested.
Thomas
I wonder why the unused bit top right. they must have a quite specific set of quarterwave mini-lines.
What format.
A set of lengths translated into quarterwave frequencies would be interesting.
dave
What format.
A set of lengths translated into quarterwave frequencies would be interesting.
dave
Looks worth investigating. Is the width of the channels about 3/32" (2.4mm)? The gasket in the middle looks it separates two layers of channels, or is breathable do you think?
Hi,
Längd=length in mm. Nr is used in the drawing. I’ve divided each octave in to 5 frequencies i.e. 150-300 , 300-600, 600-1200 …
Br Thomas
target Hz längd 1/4 nr
150 566.666667 1
180 472.222222 2
210 404.761905 3
240 354.166667 4
270 314.814815 5
300 283.333333 6
360 236.111111 7
420 202.380952 8
480 177.083333 9
540 157.407407 10
600 141.666667 11
720 118.055556 12
840 101.190476 13
960 88.541667 14
1080 78.703704 15
1200 70.833333 16
1440 59.027778 17
1680 50.595238 18
1920 44.270833 19
2160 39.351852 20
2400 35.416667 21
2880 29.513889 22
3360 25.297619 23
3840 22.135417 24
4320 19.675926 25
4800 17.708333 26
5760 14.756944 27
6720 12.64881 28
7680 11.067708 29
8640 9.837963 30
9600 8.854167 31
11520 7.378472 32
13440 6.324405 33
15360 5.533854 34
17280 4.918981 35
19200 4.427083 36
Hi Jerry!
3d printing is absolutelly wonderfull! The metmaterial is only possible when using 3D printing. There is no other way to do it.
Yes, it’s carbon fibre. It’s pretty straigth forward to get a decent seam. I sand the edges to a sharp edge like a wedge so that when I glue and press the seam it almost the same thickness as the rest of the material. I’m using my cone glue jigg to make sure that I get a proper press.
Another thing which is completely of topic on this thread is that I have placed the walsh speakers in the corner of my room which is not recomended but the result is astonishing!
Everything is improved, you should try if you can.
Br Thomas
It could be CNCed. But for mass-production 3D printing gis just startingg to have an impact.
dave