Has anyone tried an Icosahedron (20 sided with triangular facets.)

[jgaupel]

This might be hard to get "good looking."

Any Comment on the frequency response of that 2.5 inch Panasonic driver?
It seems like a good find when compared to response curves I have seen in the forum or on manufacturers / sales sites.

CHECK ON YOUR FRIENDS AND NEIGHBORS
Thanks
Jeremy

 

[jgaupel]

Johno,
This is my solution for changing baffles / drivers for testing.

CHECK ON YOUR FRIENDS AND NEIGHBORS
thanks
Jeremy

 

[planet10]

You don’t plan to install 20 drivers / box?

dave

 

[jgaupel]

Dave,

Maybe at the end of the run but for now I am mainly interested in a single or duel driver. I was thinking of getting 4 of the CHR70 drivers and placing 1 direct and 1 the next facet up. I have to check what works with a cabinet volume of .7753ft.

But to think about it I could possibly mount 20 of the buyout parts express "TV" speakers. I don't want to spend a lot on drivers that I can not use in another quality build. If I were to purchase the CHR70 or equivalent quality driver they can always be used elsewhere with known success.

I might just do it cause I think you might be kidding me a little.


CHECK ON YOUR FRIENDS AND NEIGHBORS
thanks
Jeremy

 

[planet10]

How much volume dp you have?

Can the big bezel of the CHR fit? https://frugal-phile.com/boxlib/markaudio/CH-R-P-BW-dimensions-240611.pdf

I’m thinking something smaller that uses less volume and has better extension. Doo bad they don’t come in a rectangular bezel with a small height (25-30 in a line array :^)

https://www.madisoundspeakerstore.c...mark-audio-chn50-3-magnesium-cone-full-range/

dave

 

[jgaupel]

Dave,
Yes the CHR70 fits, The cab facets were designed to handle max 5 inch bezel.
The volume is 22L.

I am not apposed to any type of box / alignment..
I have no clue about your alignment on the Onken styled cabinets but could it work adding the vents on the outside traveling from a slot around the enclosure?

thanks
Jeremy

 

[planet10]

You can squeeze 4 in, vented or sealed.ou could likely squeeze 20 CHN50, certainly 16 of them.

dave

 

[Johno]

Neat Jeremy
I imagined a pair of 5 or 10 Vifa TC9 supported by small tapped horns as a "toy" in my study. And the icosahedron scaled down to minimum.

 

[planet10]

You can do much better than the TC9 — it is an excellent TV driver but not more, the TG9 is WAY better, and the CHN50 is between the 2 and even better.

dave

 

[jgaupel]

Starting on the support woofer enclosures. I am going with the duodecahedron as it is a lot easier for the 8 inch woofers. These things are going to be big. Sorry Dave I only have 2 woofers per base bin.

And here is one of the cats making sure my panels are safe.

thanks
"A clean shop is someone else's shop" (at least sometimes)
Jeremy

 

[jgaupel]

Update
I really like the sound that these boxes seem to have. I have used 2 very different drivers and they both sounded very reasonable for a starting point. In fact I had to throw together a fast F.A.S.T OB out of a set of some old instrument speakers I had lying around so that I could continue the body work on the 20s. I was listening to them every day instead of working on them. Traditional box and crossover speakers just aren't doing it for me right now.

Yes I know that they have a long way to go. The primer is to make the imperfections pop so they may be addressed.

Jeremy

 

[jgaupel]

Update,

OK so there is so much humidity that it takes many days for anything to dry sand-able. Glue stays rubbery, primer just rolls off.
So whey not just start on the the low end cabinet assembly.

What are Your opinions on bracing?

thanks
Jeremy

 

[planet10]

What are Your opinions on bracing?

Something new to think about. I didn’t figure my small one would need any and teh triangular panels naturally resist resonance, but that might need rethinking.

Given 20 panels, i am guessing that there are actually 10 pairs of parallel sides. Taking that thot to its logical endpoints makes for bracing more difficult to build than the box i suspect.

dave

 

[Johno]

What are Your opinions on bracing?

thanks
Jeremy

Looking awesome Jeremy. Re internal bracing, given the ratio of short lengths (and the long distance between parallel sides) to chunky thickness and being ply, I think the walls would be very stiff and that the resonance, if any, would be ultrasonic. But some light stuffing would dampen that.

 

[Mr Evil]

Please tell me you're going to paint numbers on the other 19 sides.

 

[jgaupel]

Please tell me you're going to paint numbers on the other 19 sides.

Funny you should mention that. No One gets what I am describing (outside of this and other design based forums,) until I say "It's the 20 sided D+D dice." They then lose the blank glazed over eyes and say. "Oh that's cool."

I can't and don't blame them for not under standing. It's a FAST 2.1 with icosahedron sats and a dodecahedron duel driver sub. I mean, reading it out sounds ridiculous.

Jeremy

 

[jgaupel]

Something new to think about. I didn’t figure my small one would need any and teh triangular panels naturally resist resonance, but that might need rethinking.

Given 20 panels, i am guessing that there are actually 10 pairs of parallel sides. Taking that thot to its logical endpoints makes for bracing more difficult to build than the box i suspect.

dave

Dave,
The 20 sided are not getting braced unless absolutely needed as determined by testing. The 12 sided sub cab looks as if it will need something. I can work the angles out just need a suggestion of which surfaces to connect.

thanks
Jeremy

 

[planet10]

Connect all parallel walls. So 6 braces.

dave

 

[jgaupel]

sub woofer
About to finish cab sealing. Moved over to body filler for seams and blemishes. Set the speakers in for a quick pic. This thing might get painted like an Owl if I can find an artist.

But seriously any color recommendations welcome.


thanks
Jeremy

 

[Johno]

Vaguely reminiscent of a sci-fi character, maybe paint some teeth like one of Ripley's monsters...