ok fair enough, have you had any experience with the straight section but expanding cornucopya Dave came up with all sections are straight) or do you know anyone who built it? Thanks.
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Dave it looks very attractive to me for some reason. If you made it larger you could lengthen the horn but It gets a lot larger. Thanks for the info on the driver I have been reading the thread will check the driver out soon. I very much appreciate your assistance.
One other thiing Dave was there ever any headway with the idea of mass loading the horns on Coruncopya?
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Interesting, ModPodge to tame HF <10khz or very high frequency >10khz? Official response charts differ a fair bit between ferric and neodymium.
My only experience with Faital Pro was Saturday, making notch filter for 4" (inside Admark LDA 401 array element closed box), placed over old 12" Aura on top of 25L steel can (notch7.7khz 0.28mH|1.5uF|10R; LPF140hz 9mH2.6ohmAircore). Somewhat high efficiency. Frequency response and detail resolution are both good, but I haven't yet warmed to the "Pro sound". Maybe micro-dynamic contrast/articulation a bit off, or the slightly "dry" taste. Anyway, notch/passive filter is easy and reversible, though costly (Jantzen).
Candidate LXmaxi to be posted to the gallery.
I don’t know anyone who made a straight wall version. The whole point of the foam core was that it was easy to bend and shape into a curve. Straight sections is a lot more work. The corners will give you more acoustic filtering of the mids and highs so more bass relative to mids and highs makes it out of the horn mouth.
Hey Cal, has it really been 14 years? Wow how time flies when you are having fun making speakers.
Good to hear from you. I am back on this thread again.
The last thing I made out of foam core was the RAAL tractrix synergy horn with two 3FE22 drivers.
https://www.diyaudio.com/community/...ractrix-raal-ribbon-point-source-horn.352836/
Or was it the prototype to my homage to the LS3/5A, became Vanguard, became Galion TS Voyager.
https://www.diyaudio.com/community/threads/rst28f-and-dc130a-foamcore-homage-to-ls3-5a.359176/
not having had the chance to build a cornucopya yet it seemed to me (just looking at it) that straight sides would be easier to mount than working with curves but I will accept your advice and go with building with a spiral expansion.
can you tell me a few things please? how is the horn length determined for a given driver? How does one determine where in the horn expansion the line should be bifurcated?Thanks for the help.
I would stick to making the proven design pdf or image plan and scale as needed. The lengths are determined using back loaded horn theory. The cornu achieves a higher expansion ratio than any other horn. If you are new to horn design, I wouldn’t pick a cornu as the first to design. The quarter wave length and the speed of sound set the length of horn. Set lengths different by 1/3rd length of longest.
There is an Akabak script for this in the cornu thread. Modifying that will be the most effective way to change the design.
This base design has a fundamental of about 50Hz as I recall. This was by member Endia I think. Planet10 also has one with grid marks.
There is an Akabak script for this in the cornu thread. Modifying that will be the most effective way to change the design.
This base design has a fundamental of about 50Hz as I recall. This was by member Endia I think. Planet10 also has one with grid marks.
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Just thinking aloud here, but has anyone tried using the foam insulation used in construction? These come in big sheets and various thicknesses up to 6 inches/150mm. In the UK it’s used for floor insulation where they lay it down and then pour a layer of concrete over it and for roof insulation where it is cut to slot in between the roof batons. I could imagine covering the enclosure with fibreglass as a finish.
The foam consistency is quite dense and I gues it’s easy to cut and shape. To improve the internal absorption characteristics, you could score it.
The foam consistency is quite dense and I gues it’s easy to cut and shape. To improve the internal absorption characteristics, you could score it.