Midrange horn idea (ceramic squawkers!)

[Erik Mandaville]

Looking at the Altec Shawn sent, it suddenly dawned on me that it would be very easy to make something similar out of clay! We do clay slab sculpture at school all the time, and fabricate things, vessel forms, etc., that are even more complex in a technical sense to put together. In fact, various flare/expansion rates could be experimented with, as could the type of clay used. A higher aggregate content can be used to 'open' the clay body, rendering it much less prone to ringing and resonance -- far less than its original counterpart.

I think this is something really worth investigating, since the properties of sculpture clay really lend themselves to a project like this! A simple form could be built, and act as both the armature (support structure)and template for the horn.

Well, so much for that! Marie just looked over my shoulder and said "Forget it!"

...she's referring to an 'issue' I have with my back. She's right, because rolling slabs takes some work, but I MUST keep this in mind!

Handbuilt midrange horns made from stoneware clay! I think this might work really well! The horns would be fired to around 2,200 degrees F. and could be glazed in various colors of choice. For my part, I prefer the natural color of fired clay. If I built a pair of these, would some of you be willing to audition them and compare with what you're using now?

Erik

[Al Klappenberger]

Erik,

The idea of ceramic horns is interesting. It would be an neat way to make them. You could get any curvature you wanted with a mold. I think they would ring like Christmas bells though! You would need to cover them with a half inch thick layer of Dynamat!

Al K.

[sfogg]

Erik,

Using something like clay could be interesting if you tried building a horn like Edgar's "saladbowl" Tractrix horns. With a mold you could probably build the basic horn flare on a potters wheel fairly easily. The trick might be dealing with the throat and mounting of the horn.

But give your back a break!

Shawn

[sfellini]

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On 4/14/2005 6:10:26 PM Erik Mandaville wrote:

it suddenly dawned on me that it would be very easy to make something similar out of clay!

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This is the system of Jean-Michele Le Cléac'h, who was active on the Sound Practices mailing list years ago. The mid horns you see here were made to his specification for a hyperbolic horn profile. See more at http://site.voila.fr/musique_concrete

Steve.

[No Disc]

I'd be interested in wooden horn replacments. I'm surprised no one is doing this aftermarket for Klipsch Heritage.

No Disc

[Erik Mandaville]

Steve:

Thanks for sharing that -- what beautiful work!

AL: Sure, it would seem like that at first impression. In fact I have a friend, about whom I wrote an article for a ceramics arts magazine based in the UK, who makes ceramic instruments. These are not just simple whistles and flutes, but transducers. Really fascinating in terms of sound, and also great in a visual sense.

However, there are many different ways of firing clay, and an even greater number of kinds of clay. I have made clay bodies (as they are called)with a number of different aggragate materials, including vermiculite, sawdust, course sharp sand, and some others. These materials can very much effect the way the form will vibrate air once fired. Some can ring like a bell, others will be more like the 'thunk,' with almost no ringing at all. A round form, such as what Shawn proposed (I've thought about that many times, Shawn!), could be made on the potter's wheel, just like a bowl, but like a bowl, which is essentially a kind of bell, will tend to ring if some of the clay property issue mentioned above aren't worked out. Also, the fact that the internal part of the horn is sort of buttressed (I'm thinking of the Altec) with vertical sections from top to bottom, would help dampen the horn to reduce any tendancy to ring. It would be sort of self-deadening, to some degree, in that respect.

I can experiment with the maturing temperature of the clay, as well. I have found strong differences in 'ringability' between lower temp firings and those where the clay has become completely vitrified.

All that in mind, it's not something that will necessarily work perfectly the first time around. I'm pretty sure that, in terms of ring associated with such piece, I could arrive at a tap test sound of 'bink, bink, bink' rather than 'ting, ting, ting,' if that makes any sense! With even more work, we might be able to get it to a 'took, took, took' instead of 'bling, gling, sming'!

It would be really fun to experiment with! I've made ceramic enclosures for two way speakers using a press-mold techniques, where clay was press-formed into a wooden form, and that stuff didn't ring very much at all when fired. Unfortunately, that's when I taught college ceramics and had the equipment for formulating my own personal clays and glazes. I've got to do things differently now that I'm teaching High School.

I've thought also of cast bronze using lost wax casting methods, which I also used to do -- but again I just don't have access to the what's needed to do the work. In a health and safety sense, my working conditions are much, much better now. Silica in clay and glaze is not good stuff to breathe, and I was around it constantly, all day long, for years. Ouch.

Erik

[Erik Mandaville]

Shawn:

For a form like the Salad Bowl on the Titan horns, the piece would be thrown upside down, with the tapered end of the throat formed the same way one would make a bottle shape. As you said, a template could be made from anything -- 1/4 ply, acrylic sheet, etc. -- and used as a guide as the piece is made. When partially dry, this would be inverted, fit into a jig, and then trimmed as needed. The problem, is that one has to account for shrinkage that takes place both during dyring and firing, but that can be calculated and compensated for, too.

Erik

[jorjen]

No Disc, Al K. is doing wood horns for Belles and Khorns. Have'nt you been following his Trachorn thread in "Updates and Mods"? Check it out, very, very cool! I am in for a set for my Khorns. Hurry up already Al, sheeesh!.

[ben.]

Is there a way to machine or otherwise fine-tune the flare once thrown and fired? Seems it would be impossible to get a precise or repeatable flare by hand on a wheel. The molding makes sense, thougg, as does the possibility of various aggregates impacting mechanical resonance.

I had a very good friend years ago who is a talented potter. AFAIK, he still lives in the area, but his wife hates me. Haven't seen him in a long time, but my favorite coffee cups remain.

[Erik Mandaville]

Nearly identical forms can be repeated over and over on the wheel, Ben. I've made dish sets, which used to bore me to death, but with practice it's really not that hard.

Erik

[Marvel]

We had a friend who went to a certain college that teaches pottery. The school sells a lot to finance the school. My wife and I thought that their thrown stuff always looked too crude, and our firend was very offended. They did it that way because many people think it should be so if hand thrown.

Not true of course. My son was able to do repeatable shapes that almost looked like they were slip cast. It's called craftsmanship.

[D-MAN]

I suppose the main reason is weight.

Once you're over THAT hurdle, what about casting concrete?

That's far easier, and certainly won't break if it is mishandled. No kiln-work that way.

DM

[No Disc]

Jordan,

Nope I didn't know it. I guess I should make it to other forums than the 2-channel area. I'll check it out, thanks for the heads up.

No Disc

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On 4/14/2005 7:56:37 PM jorjen wrote:

No Disc, Al K. is doing wood horns for Belles and Khorns. Have'nt you been following his Trachorn thread in "Updates and Mods"? Check it out, very, very cool! I am in for a set for my Khorns

. Hurry up already Al, sheeesh!

.

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[ben.]

No offense guiys, I just thought that something as precision as horn flares where fractions of millimeters are critical might be a bit dicey. The same problem exists with wood horns, one would think.

[Born2RockU]

Handbuilt midrange horns made from stoneware clay! I think this might work really well! The horns would be fired to around 2,200 degrees F. and could be glazed in various colors of choice. For my part, I prefer the natural color of fired clay. If I built a pair of these, would some of you be willing to audition them and compare with what you're using now?

ERik:

Great idea. !!!

[Marvel]

Hard part will be mounting the driver tightly without breaking the horn.

Does anyone have a 511B that is not usable (cracked, too many broken parts of the mounting flange) that they would be willing to offer up for dissecting?

I have some ideas that I am working on, but I need the horn to take apart.

Marvel

[Erik Mandaville]

Dman:

I've been working in clay for over 20 years, taught college-level ceramics for 8 years, and forumalated my own clay and glazes used for work I sold in galleries. If you're not familiar with this type of work, I can see how this would seem improbable. I can assure you, however, it's not very difficult to do if you have some knowledge about the behavior of clay, as well as a couple of tricks up your sleeve to deal with the weight issue. If one were to mix course sawdust in with whatever the clay body one were to use for this (I would use a stoneware clay that would be fired to 2,000+ degrees F.) do you know what happens to the sawdust in the process?

That's right, it leaves pockets of negative space in the ceramic form that had been occupied by sawdust before it had been fired. This not only means a reduction in weight, but also a reduced chance for ringing and resonance. They clay would be rolled to approximately the same thickness as that of the stock metal horn.

The thought the ceramic material would not be able to withstand the high torque of a tightened driver is not accurate. Ceramic-based materials are extremely strong, especially if fired to the temps. mentioned above. In fact, modern engine components are being fabricated from clay. However, the point here is that the clay itself would not be threaded. It's too difficult to account for the shrinkage that takes place during drying and firing. Those familiar with the more recent plastic midrange horn, know that a threaded metal insert is used; which is what I would do with a ceramic horn. It would be bonded with eboxy.

Marvel: Many potters who are able to throw on the wheel and make pieces look as if they were slip cast -- don't do it. You are absolutely right that it is a craftsmanship issue, but this starts getting into the field of aesthetics. Many potters practice a deliberate distortion of form as it's being made on the wheel in order to provide, as you said, something of a human rather than machine-made quality. I had a friend from Taiwan when I was in grad school who had flawless wheel-throwing ability, and used to think work done with that intent (to look flawless) was boring.

The same thing happened to me, actually, once I achieved a certain level of mastery of working on the wheel. In art school we were challenged to be brave enough to experiment with form, and so I started altering pieces that were initially done on the wheel. This gets way off track here, though!

...I don't know, it was just a thought. I'll never know how it works unless I try, and I certainly won't let skepticism and doubt get in the way of something that might actually turn out well -- but possibly not. I will have to try in order to find out.

Erik

[sfogg]

Erik,

"The thought the ceramic material would not be able to withstand the high torque of a tightened driver is not accurate. "

Forget twist on drivers... worry about the ones with mounting bolts! Then you can use the adapter you have for the twist on drivers.

Shawn

[Erik Mandaville]

Shawn:

Bingo! What a great idea -- I hadn't even thought of that. It makes much more sense to do it that way.

...more heads are better than one for lots of things, and I appreciate that!

In any event, I don't think drivers are intended to be installed much more than snugly hand-tight. I don't go further than that.

Erik