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

ANY help from the community is VERY much appreciated. However I don’t want to put you out. We Lowther owners of the 5” drivers are in a real bind when it comes to enclosures.

What kind of driver does well in the Cornu? Each “throat” of each Cornu enclosure is short. Does it go relatively “loud” because of four mouths but not very deep because the throats are short?
 
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According to the site seb:diy:audio, the developer of the Cornu specifies appropriate drivers as having an Fs of 36Hz & a Qts of .25. My DX55 units are right around there.

I know a guy who has a slicing table for foam core (picture framing shop). He’s a jerk (I was a terrible empoyee), but I think he’d cut the “sound guides” & front & back for nothing.

Xrk971 - Thanks very much for the link to that site. Maybe increasing the depth by a centimeter or so would be sufficient for the DX55. Your work with foam core is inspirational. I could stiffen the inner surface of the front panel portion of the driver chamber with, say, 3 or 4MM plywood & some very thin adhesive sound deadening material, both of which would stiffen that area to accommodate t-nuts & better support the Lowther. It’s a heavy driver.
 
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Well, I finally got around to printing up and taping together the plans for a 20" cornu. Got out some black foamcore, and chopped up four 20" squares for the front and back. I get the plans laid out on the panels, only to find that my scaling was off a bit, and somehow ended up closer to 18" :confused:

I thought that I had even double checked and everything.

I said "screw it!" and taped the plans to the squares (centered, of course) and started laying out the spirals anyways. I'll just extend the outer channels out a bit, and bring them all the way to the edge, and space the inner channels out a smidge too, so that they work more or less as the correct scaling would.

Since the cornu is such a forgiving design, this should work fine right? I'm going for a 3" channel depth, and using the TC9FD. Just to make sure before I start cutting and gluing :)
 
Hey X, since I came up on a pair of Fountek FE85 recently, do you think they would be a drop-in for the 20x3 cornu with TC9FD, or do you think I should save them for a 24" or so build, or something else? I figured it's reputation for being a bit bright up top may be a decent match for how bass heavy the cornu can be.

I've got the 20 fronts/backs cut and the spirals drawn out, but haven't started on the channels yet.
 
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Hey X, since I came up on a pair of Fountek FE85 recently, do you think they would be a drop-in for the 20x3 cornu with TC9FD, or do you think I should save them for a 24" or so build, or something else? I figured it's reputation for being a bit bright up top may be a decent match for how bass heavy the cornu can be.

I've got the 20 fronts/backs cut and the spirals drawn out, but haven't started on the channels yet.

The FE85 is a perfect match for a 20in to 24in Cornu - about 2.5in to 3in thick should work fine. I would personally go with 24in and 2.75in. But since you have 20's all drawn out, go with that.

Good luck.

...now back to work on that sim for the Karlsonator for you...
 
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I do not mean any disrespect on this build by wanting them for height channels...I am building k402 synergy style horns for the front channels. I am also building some Klipsch Belle bass bins with some 18x10 horns for the surrounds. I am wanting something better than my JBL 8330As for my bvb height channels for an eventual Auro3d setup.

Does anyone know how they would do 12' up a wall?