Ever think of building a Cornu Spiral horn? Now you can!

Founder of XSA-Labs
Joined 2012
Paid Member
I think you may need to go up to 45in in order for there to be enough room in the back for the basket and magnet if you want a 6.5. Might as well make it 48in. A sheet of plywood will give you exactly 2 pieces for front and back.

Fostex FE167 can work. A car audio 6.5 coaxial would be neat to try if you have one lying around.

Dayton PS180-8 is another choice - that would be my pick. High tech Nd motor with shorting rings, cast basket, phase plug, inverted surround, Klippel tested, 95dB, 5mm xmax. $100.
 
Last edited:
Sadly I've already started the 40 inch box. So, I wouldn't be able to go up to the 45 inch.

Like you said a 6.5 coaxial would be interesting. Would there be a benefit to having a tweeter and would there be a crossover needed?

Yeah, i'm really looking at the Dayton ps180-8! Thanks for the recommendation!
 
Nice long thread! Just finished reading, took some time.
After so many good rewiews, I decided to begin construction of a pair of Cornus for TV audio in the bedroom.
I already have some pairs of Fountek 88 3” and Tang Band 871S. They both sound nice, but…which one would be better for the Cornu?
I’m thinking about scaling the PDF to a 19” box with 2.6” channel deep. Is that ok?
Thanks.
 

Attachments

  • 2-drivers.jpg
    2-drivers.jpg
    41.1 KB · Views: 507
Well, I have the 40 Inch Cornu up and running with a Dayton audio PS-180-8. I'm on the fence about the sound, I feel like it's really lacking in the mid range. The bass sounds amazing and the treble is alright. I'm not someone who has listened to a lot of audio setups so I don't know if I'm being overly critical.

I did make the box a little different that everyone else. I used chipboard for the box material, I constructed one side where I hot glued the 6 inch strips to back of one sheet. Once the spiral had been glued down I soaked the whole thing in a couple layers of polyester resin. Once this set up hard I put in the baffling material and cut the hole for the driver. I then laid down a thick layer of resin and sandwiched the two layers together. The box is very sturdy and very light.

I'm powering the speaker with a lepai Lp 2020A+ amp that seems to give the driver more than enough power but everything seems a little muffled or flat. I've played high quality digital FLAC files and also directly from my record player. The high quality digital files do sound better but still a bit soft.

Maybe it will take me a little bit to get used to it?
 
Mini cornu

Almost done. All that remains is to attach the face to the spiral. The face is 4 mm plywood and the spirals are foam core.
Driver is Tang Band 871S, an old model that was popular a few years ago and I still have a few of them unused.
I'm still deciding on the glue to fix the face to the core baffle, because only the face is wood and the rest is foam core. Would white carpenter's glue enought? Or perhaps silicone sealant would be better? Which one would give better sealing for the spiral channels? Not a clue on this choice.This is my first foam core project! Any suggestions? Thanks.
 

Attachments

  • Cornu-almost-done-martes-10.jpg
    Cornu-almost-done-martes-10.jpg
    48.7 KB · Views: 534
Last edited: