Have y'all seen these?
MultiCell Horns For JBL,BEYMA Compression drivers | eBay
For the price I'd be super interested, if they weren't on the other side of the Atlantic
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Have y'all seen these?
MultiCell Horns For JBL,BEYMA Compression drivers | eBay
For the price I'd be super interested, if they weren't on the other side of the Atlantic
Yes the cost of shipping across the pond will likely be more than the actual horns,right now they are $405
He says 300hz horns so I'm thinking 1503's maybe ? I would like to try a pair !
They look nice that's for sure but the point where the waveguide attaches to the multicell is much larger than an Altec and I wonder if the outside cells would be receiving as much input as the more centred ones?
It says there's different throats for 1 inch or 2 inch drivers. :)Quote:
Originally Posted by Cal Weldon
I was looking at that too.Where the cells come to form the throat they are supposed to be paper thin.Hard to do if not impossible with MDF !!
There is a fellow in Sweden who made his own from wood. At the throat end of the cells he sanded it down to super thin.
Easily done.Quote:
Originally Posted by Panomaniac
But first you must saturate the wood with cyanoacrylate adhesive(super glue) and let it harden completely, this makes the wood more akin to hard plastic allowing it to be sanded/milled to very thin dimensions with good strength and stability.
It would probably even work with MDF, maybe requiring multiple applications.
Other end of the waveguide. :)Quote:
Originally Posted by cradeldorf
I like bowtie's idea.
I actually picked this up from a professional wood carver who specialized in birds in natural poses.Quote:
I like bowtie's idea.
A word of caution should go out with the idea. when heated to or near the point of combustion, cyanoacrylate releases cyanide gas. There have been at least a couple cases where carvers using wood burning pencils for detailing have suffered serious health effects from the smoke including at least one case of blindness.
Yes I seen that thread, Petter is a true craftsman ! Beautiful job !Quote:
Originally Posted by Panomaniac
http://www.diyaudio.com/forums/multi...ml#post1718863
http://proxy1.pixbox.se/arkivet/synl...0/23490402.jpg
:eek2: I don't see myself using that anytime soon ! :wink2: My luck I would be getting my fingers stuck to everything !Quote:
Originally Posted by bowtie427ss
I'd like to build a little multi cell out of card or heavy paper that would do tweeter duty. Each cell would be tiny, tho, as the whole thing might be 4-5" wide.
Might that be a little too absorbant a material? ie: over damped, perhaps affecting the response?
I dunno. I did build some 1" throat tractrix horns out of very heay paper mache when I was on Maui. Put the 806 drivers on them. The sounded very good indeed.
But for the top 2 octaves it's a good question.
Depends on how well the horn surfaces are sealed. The structure itself should be so far below a tweeter's operating range that it will be akin to a large, low tuned, tar damped, multi-cell.Quote:
Originally Posted by Cal Weldon
So the 'name of the game' is to find a material that's either super slick or at least doesn't swell up to cause a micro rough fibrous horn surface when coated with 'whatever' to seal it. FWIW, the thin plastic used to stamp out hotel/motel 'maid service' doorknob hangers is what I've used for tweeter WG experiments, then contact cemented sheet cardboard on the outside to create a well damped, yet rigid enough, constrained layer construction.
Unfortunately, I don't know what type plastic it is or where to get it these days, I special ordered it from a long gone hobby shop as sheet stock of varying thickness for making slot car front/rear air dams.
GM
Maybe Styrene ? I know you can order it in pretty much any size.But as it is a petroleum based product it is expensive !
Dunno, it's somewhat opaque in a 'milky' white sort of way if that helps.
GM
I'll make them out of celluloid! ;)
OK GM, I might have to ask for your help with Hornresp to build a profile. I just don't "get" that software. Wish I could figure it out.
Do they market any thick enough to have any rigidity?
Yeah, it's not very intuitive and not sure I even know about/have tried, all it's capable of, but then when it comes to horn design I usually 'run the numbers' in Excel and just load/sim it in HR, though of course it can't do multi-cells per se.
Regardless, glad to help as much as I can, though may not be real swift to respond due to spending virtually all my quality time these days doing major repairs or recovering from them, so for now only sit at the computer while I'm waiting for the latest round of NSAIDs to kick in.
GM
Sorry to hear that, GM.
+1 Me too GM. Hope things get better for you !Quote:
Originally Posted by Panomaniac
Slot car body's and plastic car models are polystyrene plastic, toss some white stryrofoam into some acetone and you'll get polystyrene. :)Quote:
Originally Posted by GM
Will it be mush? Could it be formed or molded?
GM. Is there a horn spreadsheet somewhere that will give me an exponential profile for making something like this? I'll look for one, if you have one please let me know.
Thanks for the thoughts guys, sometimes when you roll the dice you get 'snake eyes'. At least I'm still rolling, I've already buried way too many friends, relatives, acquaintances that didn't make it to retirement age, or if still alive, can't do much of anything physical anymore, in pain or not. Doesn't mean I'm not frustrated/mad/bitter about the circumstances that has put me in this position though!
True, toy slot cars are made of polystyrene plastic, but since the late '60s all the racing classes I've been involved in use clear Lexan bodies that you paint from the inside and it just dawned on me that's what the various sheet material I have is, just thicker, with the thickest being the milky colored one.
There's a number of [expo] calculators on the net, but I've lost the links.
Googling:
Exponential Horn Calculator
mh-audio.nl - Expo Horn
Single Driver Website
This one you can use on-line or DL and if they haven't dumbed it down/'streamlined' it/whatever, an excellent one:
Ishtek
Ishtek
GM
BTW, I'm not getting instant email updates even though it's listed in my 'general' settings plus my subscription folder only has [14] when it should be in the hundreds at least and maybe over 1 k since I have well above this on several other forums, so are they lost forever?
GM
It'll probably be mush until the Acetone evaporates.Quote:
Originally Posted by Panomaniac
Aircraft plywood is readilly available in 1/64", 1/32"', 1/16" and 1/8" thicknesses. The material would offer greatly improved stiffness over paper. The thinner two thicknesses are easily cut with heavy duty scissors, the 1/16 with metal shears. Aircraft Spruce and Specialty would be a good place to try. Sheet fiberglass and carbon fiber are available in any thickness you like as well.
The construction technique is pretty simple as long as you have accurate patterns to work with. Contact cement the patterns to your material, cut your pieces, tape together with masking tape and glue together from the inside with cyanoacrylate (CA) in a well ventillated area, or epoxy. After the glue has set the joint can be reinforced un the outside with fiberglass etc...
Ed
Thanks guys, I'm going to have to try a mutli-cell tweeter.
Looks like a Fun project Pano !
Most likely. Acetone will also dissolve butyrate which will re-solidify as the Acetone evaporates.Quote:
It'll probably be mush until the Acetone evaporates.
I would be very careful with styrene tho as it's sensitive to a wide variety of petroleum distillates and light hydrocarbons.
I'm in the process of cleaning up from a major flood in which i lost a full tank of heating oil in my basement. Styrofoam peanuts all melted and have re-solidified, they look like disgusting hunks of snot. However, they are quite hard and thier edges can be sharp enough to cut you. Rigid foam insulation also dissolved and re-hardened into dense, hard, and sharp chunks of styrene plastic.
My point here is that some of the distillates and hydrocarbons found in the fuel oil are also prevalent in a number of stains and finishes that we like to use on speaker cabinets. Be careful what you mix, and/or expose.
Just to clarify and reiterate, there's no danger until it is heated to the point of combustion or just slightly below. Keep the soldering iron and open flame off it and all should go well.:)Quote:
I don't see myself using that anytime soon ! My luck I would be getting my fingers stuck to everything !