Steel/Aluminum Horns?

[kwampaku]

Would say, 16 gauge cold rolled steel or aluminum sheet be inappropriate for use in the construction of horns such as the Hedlund? I realize there may be resonance issues but these may be overcome by the application of a suitable coating (mastic) or bracing to dampen the resonance. I note that various vintage horns and backhorns appear to be fabricated from sheet metal or metal stampings.

Considering the speed of fabrication I am left to assume that the absence of horn projects utilizing these materials is due to intrinsic sonic considerations.

kwampaku

[Cal Weldon]

I made some HF horns from 16 ga steel. I had a problem with the distortion of the metal while welding. Made two and never did anything with them. A good deal of the commercial horns are cast aluminum

[Pit Hinder]

kwampaku,
you as marine engineer probably know that a curved surface is stronger than a flat sheet, so the Hedlund offers itself (I don't like it, but that's my taste, not based on having tried them)...but, as Cal mentioned, welding them might be a nightmare. Go and try, though - I'll keep fingers crossed.


Pit

[pesky]

many wonderful horns were made of cast aluminum "back in the day" the resonance problems were overcome by applying thick rubber to the backs of the horns, usually with contact cement or mastic. Steel horns weren't very popular because of weight. It is difficult to create a sheet metal horn due to the reverse draft necessary to make a biradial. Newer designs don't use the reverse draft, but pay for it in sound quality due to standing waves forming in the interior of the horn. Most of this is now overcome with computer software that corrects phase, and compensates for radical eq problems (aka the new series crown amplifiers that are 7000 bucks.)

today, all you have to do is get close, and learn how to correct the problems with a tef (time energy frequency) analyzer program and the accompanying amp/crossover/phase corrector/equalizer combinations that have become all the rage.

[Spasticteapot]

I'm having someone build me a pair of PAWO horns out of birch. (Free birch is good birch!)

I wonder how much it would cost for the steel to build a solid-metal PAWO horn? Probbably a lot.

[Daveis]

I once thought about using http://www.emachineshop.com/ to make me a horn out of laminations of 1" thick aluminum CNC cut into a horn shape. As these seemed silly expensive I gave up on it.

For much less money I can "bend" wood by moistening it for 2-3 days. I've seen solid pieces of lumber turned to noodle by steaming. This for making a boat.

[Spasticteapot]

Originally posted by Daveis
I once thought about using http://www.emachineshop.com/ to make me a horn out of laminations of 1" thick aluminum CNC cut into a horn shape. As these seemed silly expensive I gave up on it.

For much less money I can "bend" wood by moistening it for 2-3 days. I've seen solid pieces of lumber turned to noodle by steaming. This for making a boat.

Well, yes.

Or, you could take the old-fashioned approach, and hammer it out of sheets of metal.

Or cast it, for that matter. Lost-wax casting is remarkably effective.

I have some decent metalworking ability, and if a reasonably soft material (copper?) were used, making horns would not be that hard.

[Pit Hinder]

Pesky,

R U sure? I only use my Ultracurve for measuring, not for listening - the added A/D D/A conversion somehow takes the "soul" out of the music.


Pit

[pesky]

the faster your device the sweeter the sound. Most commercial companies are taking this route, since they can "cheat" physics and create horns that are shorter, and fit into a "commercial"enclosure. JBL is one, which is why they partnered with Crown.

Metal horns produce glistening highs, which is really nice, wooden horns have a more mellow sound, which is great for near field listening. You could create a wooden horn buy using slabs of wood cut from templates made in any 3d program, glue the whole thing up and polish it when finished. Make 2 halves and glue them in the middle.

I know of one major sound company that made horns this way for years. Mass is your friend here, since it overcomes any resonance of the device.

96khz, 32 bit bitdepth is about all that is cheaply available as a conversion device, check out the presonus firebox, or firepod as low cost a/d d/a. There are some more expensive ones, like motu for about 3 to 5 times the street price of 300 dollars (US) for the firebox.

You also have to have a 'rippin computer. The Lake company makes a crossover (for about 7000 dollars US) that includes risc processing, high sample rates, and is completely adjustable with crossover curves up to infinity, and a 100db of cut and boost at any frequency. It also time and phase corrects, you just have to know how to use it.

[kwampaku]

This isn't quite what I had in mind but you'll get the general idea:

Solar Powered Steel Horn

I'd say that the claim of incredible dynamics and concert volume levels may be suspect but the construction method is along the lines of what I had in mind.

The caption at the site this was linked from states that this speaker/scultpure is some 12 feet tall. Looks a bit unstable.