If you want to explore the power of foam core, try something a little more exotic than a BR. Make an accidental MLTL: design your box volume and vent for a BR as usual but instead of golden ratio - make it tall and slender with same volume. At least 30 in tall and put vent at bottom and driver about 1/5th to 1/3rd of TL length from top. Put stuffing in upper part of chamber up to a little past driver. At worse, you get BR but most likely it will improve extension and smooth it out - and load the cone better for less excursion and higher SPL capability. About same amount of work as a golden ratio BR but a better speaker. More info in the Accidental MLTL technique thread.
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This may enable some interesting creations...
GJQG18 Nine Sea Compass Circle Cutter Cutting Tool 1cm-30cm Diameter NEW | eBay
GJQG18 Nine Sea Compass Circle Cutter Cutting Tool 1cm-30cm Diameter NEW | eBay
When mine arrives I'll let you know how it cuts foamcore
Hope it works well. I have always drawn circle then use xacto blade to cut circle. May not be perfectly clean circle but then driver rests on it so you don't see it.
But loads of rings could be cut from one 30cm circle and a dome come be made
.. which is what I was thinking.. not just speaker cut outs 300 - 270mm inner 15mm thick ring..
270 - 240mm inner....
... 60 mm
9 x 15mm wide rings.. or 45mm thick from one 300mm circle
295...265....... ..
290...260 .... ..
3 sheets of A1 may enable 405mm of curved cabinet
Hi All,
It took me a long time to read all posts!
I am trying to build my own cornu with a piece of depron I have.
but according to this post:
http://www.diyaudio.com/forums/full...-board-speaker-enclosures-80.html#post3290685
I don't really understand if I have to adjust the plan posted by planet10 for 74cm.
I have this driver: Fountek FE 85
Products_Fountek Electronics Co.,Ltd
If possible I would like to build a smaller cornu (like 20' or 50cm).
please, can someone help me to understand if I have to adjust the plan to my driver? What size? What height?
Thanks for your help
It took me a long time to read all posts!
I am trying to build my own cornu with a piece of depron I have.
but according to this post:
http://www.diyaudio.com/forums/full...-board-speaker-enclosures-80.html#post3290685
I don't really understand if I have to adjust the plan posted by planet10 for 74cm.
I have this driver: Fountek FE 85
Products_Fountek Electronics Co.,Ltd
If possible I would like to build a smaller cornu (like 20' or 50cm).
please, can someone help me to understand if I have to adjust the plan to my driver? What size? What height?
Thanks for your help
For the FE85 scale the Cornu down to 20 inches and as large as 24 in x 2.5 in to 3.0 in deep. It is pretty forgiving to small variations within that range.
Good luck with the Depron.
Camelator,
Thanks. The plan just needs to be scaled - you don't need to modify the design specifics other than to scale it. There may be things like changing the driver chamber volume independent of the plan but that is an advanced topic that takes some modeling first. If this is your first Cornu, just build it to plan ( scaled).
Good luck!
X
I just found an old sim I did of the FE85 for a 24 in x 2.5 in deep Cornu. One thing you have to watch out for is the possible cone excursion at low freq since this driver does not have a lot of xmax. You might have to play with stuffing of the horn mouths near the exit to reduce the midbass while still letting the low bass come out. Good luck!
