Same. Before hearing the 1505 I’d had good experiences with the 1005, a superb horn, but the 1505 is even better and so natural sounding. I suspect that a lot of the criticism of multicells is based on how they look, not how they sound.
Yes my goal is to figure out a proper size of this horn to match with a 12” woofer for domestic Hi-Fi use. Any ideas?
I always thought those multi-cell ALTECs were works of art. Form followed function with grace and purpose.
Your horn is beautiful. I hope its actual performance will be just as beautiful.
Your horn is beautiful. I hope its actual performance will be just as beautiful.
Well , you're smarter on this stuff than me, but heck, Ok, I"ll play. : )
So we seem to be on the same page re: 12" woofer. But from there I can see too many questions. Are you thinking domestic Hi-Fi in general? your pad? maybe sell? maybe kick some Avant-Garde butooshka? (Am I allowed to say that word - tooshka?)
You might want to print that with lots of wall layers and heavy infill (if not solid). Some of my printed horns buzzed a lot from iffy attachment inside and wall resonances, until I beefed them up. Costs more filament, though.
So far no infill, just walls. It isn't very thick, but it is well braced by its structure. I would not be surprised if it needed more thickness, even the metal horns benefited from being tar filled. Definitely a concern. 
Mostly that. A 12" woofer and 1" compression driver are a classic combo but the horns are often rather different. I need to go look at what has been popular with the Econowave projects.
Been thinking about it. Should be sonically dead, right? I have made papier mache' horns and they were very neutral indeed.
Should it be sonically dead? The best horn I've heard was the TAD 4001 in baltic birch. Big chunk of dense hardwood. Didn't sound like a horn at all to me, a major departure from the honky, nasal quality I usually hear in them. Since papier mache is essentially wood pulp I'm not surprised yours were neutral. Maybe this one could be wrapped in it, couple of layers? Or a high wood pulp filament could be used instead?
I like the idea of neutral, not sure about dead...
I’ve always liked the 90 degree corner design used here for the woofer(originally lifted from jbl or altec?) if you go down to the second design the horn is on top. The long distance from the front to the rear point give a nice space for the horn to live.
https://josephcrowe.com/blogs/news/...y-15-2-way-monitor-using-sb-audience-products
Crossover point seems to be 500-600hz? To me longer horns are more aesthetically pleasing.
The sealed 15” has a many attractive qualities and would probably be outstanding. I know many would disagree but I would be looking for an f3 of >32 so maybe a ported 12” gets there? Proper mating to the horn is more important
https://josephcrowe.com/blogs/news/...y-15-2-way-monitor-using-sb-audience-products
Crossover point seems to be 500-600hz? To me longer horns are more aesthetically pleasing.
The sealed 15” has a many attractive qualities and would probably be outstanding. I know many would disagree but I would be looking for an f3 of >32 so maybe a ported 12” gets there? Proper mating to the horn is more important
Bill Woods' 700Hz aluminum conicals were pretty solid.
Me too. If all the perimeter cells are identical then printing cheap and laying something to stiffen is an obvious thought , but reality of actually doing it isn't so convenient. I guess one pivotal question at this point is how much of the process you want to do with the printer. Are you hoping to go start to finish with it?
If you like hand work then printing forms, smoothing with body filler and using those as forms for papier mache' is not outrageous. Slow though.
Wondering how much this has to do with the horn and how much is having fun with the printer. Remembering Petter's multicell thread and the fact you can get 3mm panzerholz in 4x8 sheets has often made me think admiringly about the virtues of CNC machines.
I've always liked the corner horn idea too, particularly the Olson . Years ago I saw one with one of Woods' 700Hz horns that looked great yet not in your face . . . . . . but the corner horn is more limited in adaptability to room layout or structure than other enclosure designs.
Still . . . . . . some day . . . . . .
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To me they sound better than short horns and waveguides.
That would be nice, but it can't vibrate along with the music. So we shall see.
Looking at the head-on shot again, I wonder if the angle between centre axis and those of the outer cells isn't a little wide for the higher frequencies. , A lower cutoff design done longer might make it easier to straighten the outer horns a bit, narrowing the angles, if that's what it needs. (It really is a question.)
LOL. Maybe I never posted the videos here but a couple of years ago a large colony of bees took over an outdoor speaker I built. It was a lot of work to get them out safely. Maybe I don’t want to temp fate and use these horns outside. 😀
The profile of the individual cells is somewhere between expo and catenary. I found it difficult to get an exact expo profile and still get the curves and shape change I needed.
Flare rate I don’t remember but it should not be hard to figure out.
The profile of the individual cells is somewhere between expo and catenary. I found it difficult to get an exact expo profile and still get the curves and shape change I needed.
Flare rate I don’t remember but it should not be hard to figure out.
I wonder exactly the same thing. The curved cell might attenuate the HF a bit, they usually do. I managed to keep the throat in view for most of the angle of the hex cell, so attenuation should not be awful. But one of the main points of a multi-cell horn is the good routing of the HF to the edges, meaning not much beaming.
A longer horn (for the same mouth size) would mean a less severe cell angle and a gentler curve. The curved cell is used here to allow the cells to meet right at the throat and take up the entire throat area. Of course it doesn’t have to be that way, but that was my goal for this horn.
I simulated them in Hornresp running the cells individually and as a set making up the entire horn, they show a cutoff frequency circa 875Hz.
For reference my prototype is about the size of a FaitalPRO LTH102 horn. The Faital is a Tractrix horn, though.
Sorry for the pedestrian questions but hey, it's my level .
Does printing make it so so that all cells need to share walls or can the whole thing be done with each cell being discreet and only joined at the two ends, like the 1505 ?
Does printing make it so so that all cells need to share walls or can the whole thing be done with each cell being discreet and only joined at the two ends, like the 1505 ?
Thanks for asking!
It can certainly be done with all discrete cells and then glued together. I did model one built that way, but didn't print it. Well, I sort of did, this blue one was printed cell by cell and then glued together. I would not do it that way again, though - not for a horn this small.
You don't want perfectly straight cells with this geometry, think about it.
(soccer ball, geodesic dome). But I have drawn models with all hexagonal cells and straight walls. There is a cheat to that, if you think about that one too. (hint: shape of the cells). I wasn't too happy with the way the cells arrive at the throat, but perhaps a throat adapter could patch that, as it certainly works well with other multi-cell horns.
It can certainly be done with all discrete cells and then glued together. I did model one built that way, but didn't print it. Well, I sort of did, this blue one was printed cell by cell and then glued together. I would not do it that way again, though - not for a horn this small.
You don't want perfectly straight cells with this geometry, think about it.
(soccer ball, geodesic dome). But I have drawn models with all hexagonal cells and straight walls. There is a cheat to that, if you think about that one too. (hint: shape of the cells). I wasn't too happy with the way the cells arrive at the throat, but perhaps a throat adapter could patch that, as it certainly works well with other multi-cell horns.
Pano,
The single cell reminded me of Beethoven's ear trumpets from the pre-electronic era:
I'm curious about the hexcell polar pattern, can't mentally decide whether I'd want two cells facing the ceiling and one facing the floor, or the other way around, or rotated 90 degrees...
Have you listened to (or through 🙂) the horn yet?
Art
Well then, my next question is, What happens when length from throat to exit along the surface of one wall is shorter or longer than that on other sides?
I'm thinking make it out of straight (ie. symmetrical around the axis) or at least straighter sections than the blue and then shorten the walls that form the outer perimeter to get the soccer ball exit. Is that naive ?
I'm thinking make it out of straight (ie. symmetrical around the axis) or at least straighter sections than the blue and then shorten the walls that form the outer perimeter to get the soccer ball exit. Is that naive ?