I keep coming back to this thread, especially because of my first attempt, and the high WAF!
I was wondering, has a version for the FaitalPRO 3FE25 been created? I'd like to make something less obnoxious than my current TV/HT speakers (Cerwin-Vega MTMs that have a lacking midrange).
I may make a sub to couple them with.
Thanks in advance!
Dan
4FE35's have been done http://www.diyaudio.com/forums/full-range/225622-ever-think-building-cornu-spiral-horn-now-you-can-193.html#post4149913
Ok.
Before I get round to building this bigger horns in plywood, I am going to build a smaller pair for a friend out of the 5mm foam core board. I have 2 X Visaton FR10s and can get a 600x600mm panel size from the A1 size board I just ordered.
Any idea how deep I should aim for? I was thinking maybe 75mm, but would appreciate any other thoughts on the depth.
Brad
Before I get round to building this bigger horns in plywood, I am going to build a smaller pair for a friend out of the 5mm foam core board. I have 2 X Visaton FR10s and can get a 600x600mm panel size from the A1 size board I just ordered.
Any idea how deep I should aim for? I was thinking maybe 75mm, but would appreciate any other thoughts on the depth.
Brad
Sorry. To clarify, I meant scaling the design for the 4fe35 speaker down to match the 3fe25.
I don’t know why I’m posting my tiny Cornu build when I’m faced with the much larger and better Cornu builds that have been posted and discussed here! Maybe I can plead temporary insanity afterwards! 
I have to confess that I built these micro Cornu speakers [14” x 14”, 2” depth, 0.39” (10 mm) throat size] with cheap 2” (4 Ohms, 3 watts) computer drivers some time ago. I don’t know whether anyone else built the micro Cornu after xrk971 built his, and the cardboard Pizza box Cornu by MG. So I held back.
I've been following this fascinating thread and the foam core board thread for quite some time now and the enthusiasm of, inspiration and patient guidance given by both xrk971 and Cal Weldon and contributions by many members had been instrumental for my taking the plunge finally.
I started out by building a mini Cornu [22” square, 21” spirals, 3” depth] using locally manufactured 3" Peerless FR drivers mounted on 6mm bamboo plywood baffles and 12 mm regular plywood back panels. I had to shelve the project mid-way temporarily when I found that the uneven surface of the bamboo plywood baffle would not make a good seal on the spirals. I was set on using these baffles so I decided to build the micro Cornu using the same kind of material, on which I lined the inner part of the baffle with 5 mm EPE Foam sheet. This was a sort of proof of concept (adding the EPE Foam linings to the inner side) and the idea worked! It also allowed me to adjust the damping several times without having to glue the baffle. For the micro Cornu, I used a PDF drawing of a round spiral that was posted in this thread. (Thanks for that PDF, Nathanjh13!)
The EPE Foam Lining -
Damping the spirals -
The semi completed Cornus -
The completed micro Cornus -
The micro Cornus are really loud and have very impressive bass. Overall - a considerable improvement in performance from the tiny drivers than when they were fitted in the 3” cube plastic enclosures originally.
I have to confess that I built these micro Cornu speakers [14” x 14”, 2” depth, 0.39” (10 mm) throat size] with cheap 2” (4 Ohms, 3 watts) computer drivers some time ago. I don’t know whether anyone else built the micro Cornu after xrk971 built his, and the cardboard Pizza box Cornu by MG. So I held back.
I've been following this fascinating thread and the foam core board thread for quite some time now and the enthusiasm of, inspiration and patient guidance given by both xrk971 and Cal Weldon and contributions by many members had been instrumental for my taking the plunge finally.
I started out by building a mini Cornu [22” square, 21” spirals, 3” depth] using locally manufactured 3" Peerless FR drivers mounted on 6mm bamboo plywood baffles and 12 mm regular plywood back panels. I had to shelve the project mid-way temporarily when I found that the uneven surface of the bamboo plywood baffle would not make a good seal on the spirals. I was set on using these baffles so I decided to build the micro Cornu using the same kind of material, on which I lined the inner part of the baffle with 5 mm EPE Foam sheet. This was a sort of proof of concept (adding the EPE Foam linings to the inner side) and the idea worked! It also allowed me to adjust the damping several times without having to glue the baffle. For the micro Cornu, I used a PDF drawing of a round spiral that was posted in this thread. (Thanks for that PDF, Nathanjh13!)
The EPE Foam Lining -
Damping the spirals -
The semi completed Cornus -
The completed micro Cornus -
The micro Cornus are really loud and have very impressive bass. Overall - a considerable improvement in performance from the tiny drivers than when they were fitted in the 3” cube plastic enclosures originally.
Hi xrk971,
Praise from you is high praise indeed!
I used PVA glue, the type that furniture makers use. I also asked a few upholsterers whether PVA glue could be used with the foam lining and they said it would be fine. I coated the entire lining just to ensure that there was no leakage.
It's very hard to find Fostex drivers in Turkey. Is it possible to use some drivers that are for car audio. I have found these and thought it may work in 75cm version.
TS-G1014R 10cm Dual Cone Speakers (180W) - Pioneer Car Speakers, Sub
There are many more 10cm (4") coaxial drivers that can be considered full range over here. Has anyone tried something like that. I tried to read the thread as much as possible but couldn't find anything similar. Just once someone asked about it and Cal says they are for cavernous enclosures but it seems no other replies. Maybe someone has tried later?
TS-G1014R 10cm Dual Cone Speakers (180W) - Pioneer Car Speakers, Sub
There are many more 10cm (4") coaxial drivers that can be considered full range over here. Has anyone tried something like that. I tried to read the thread as much as possible but couldn't find anything similar. Just once someone asked about it and Cal says they are for cavernous enclosures but it seems no other replies. Maybe someone has tried later?
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Ok, I am getting the Monacors! but I have another question;
Why is the middle plate needed? Is it to hold the guides? The guides could be flushed a few mm's into the front and back plates. The guiding carvings can be done accurately with a cnc. Then there will be only 4 horn pathways. Does having 8 adds to anything? I see some has it and some don't. I will use mdf and bendy plywood. I have access to CNC
Why is the middle plate needed? Is it to hold the guides? The guides could be flushed a few mm's into the front and back plates. The guiding carvings can be done accurately with a cnc. Then there will be only 4 horn pathways. Does having 8 adds to anything? I see some has it and some don't. I will use mdf and bendy plywood. I have access to CNC
Thats great news! I am thinking of maybe using a clear acyrlic panel for the top board. I wonder how it will sound. I would need to find a way to find the stuffing in the speaker look good too. The central parts will need more stuffing, so maybe the central part (around the driver) can be opaque and it could become clear after that.
Hi all, my name is Giuseppe, writing from Madrid.
A couple of years ago (2103, January) I wrote looking for help to define measures for a Cornu with Eikona speakers.
User xrk971 answered kindly ( post #1396)
After that things of life make me put apart the project and the new Eikona remained unused, until January 2015 (now) when the situation pemitted work again on the old project.
First thing : the foam you use to build the channel here in Spain is called “carton pluma”, I say so if more spanish people try to do it, they will know what to buy.
I can confirm that it’s very rigid apparently but making small cuts help a lot.
Second : have two 75 x 75 (centimeters) mdf pieces, on which have redrawn the spirals and these days I’m cutting the foam to make the spirals.
I’ll try to upload photos, the mail is to thank for the help, even if after two years.
Best regards
Giuseppe
Just back in town now and glad to see these things are still showing the appeal they did when X showed us how to do it way back when.
X, I believe the unit with the small pieces was a copy not an original. I think DC used long bendy pieces.
Well I finished (and started) the second of the pair yesterday and got it sealed up. Am listening to them now. Did some work on stuffing the first one a week or two ago and found it really, really needed a lot of stuffing in the chamber. Putting some in each of the four mouths, just behind the first bend, also helped get rid of higher frequencies escaping from the horns and ruining the mids.
While I listen to them now the bass is definitely there but it seems out of phase. I'm quite sure I haven't hooked them up wrong. I looked another build picture here and they were a mirrored pair. Mine ain't. Could that be it? I guess I'd just have to seal up the hole for the driver and cut a new one in the back to make one mirrored but I'd rather not do that before I get some input. Are they supposed to be like that?
While I listen to them now the bass is definitely there but it seems out of phase. I'm quite sure I haven't hooked them up wrong. I looked another build picture here and they were a mirrored pair. Mine ain't. Could that be it? I guess I'd just have to seal up the hole for the driver and cut a new one in the back to make one mirrored but I'd rather not do that before I get some input. Are they supposed to be like that?
following on from this I am now just about to start to put this horn together. I am going for 85mm deep!!!!- cheers XKR971. The scaled plans are now 22 inches square and I have a question about the driver mount and horn mouth openings. At this scale the circle cut out for the driver is only 3 inches and it looks like its going to be pretty tight to get a 4 inch driver in there, without removing some of the initial curved horn material.
What have other builders done to get round this? I will be able to get the 4 inch driver to fit, but might need to reduce the horn length by about 4 inches.
lol. I may even find I can get everything to fit when I try the build, but wanted to see if anyone had encountered the same problem.
cheers
Brad
Brad