| Fuling |
Hi
I´m waiting for a pair of Fostex FE107E´s that should arrive sometime next week, my plan is to use them in opens baffles from about 200Hz and up.
When I searched the net for info and inspiration I found this lovely little backloaded horn, the Buschhorn.
It seems that there are several different versions around and at least two different sizes (for 3" and 4" drivers), and People use alot of different drivers in them. Most common are FE 83, FE 103 (Sigma) and FE108, never seen one with FE107E though.
Any particular reason for this? Is the FE107E a bad choise for this horn or something?
I´ve always been interested in horn speakers but never had the chance to try a pair (except for some wild and discouraging experiments in my early youth).
This design seems easy to build, so I think I´ll build a pair of cheap chipboard prototypes when my drivers has arrived.
If anyone has experiences from this design or similar ones, please tell me about it!
Cheers
Daniel |
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| Colin |
If you type Buschorn into Google, you should find a few sites that describe built versions. There's even a Mk 3 out there somewhere. The fullrange driver forum has lots on the Buschorn too.
The horn shop also features a horn which is similar in layout to the mk 1 Buschorn. It's a commercial product so no design details but the review links should give you a feel for the sound. The TNT Audio reviewer liked it so much he bought it.
Finally, zHorn has three horns similar to the Buschorn - with the main differrences being that they vent forwards, rather than to the rear. The plans are on the site and the designer is a regular on the full range driver forum. I think these look better thought through than the Buschorn. If I was going to have a go at a mini-horn, I think these are the ones I'd tackle.
Have fun and keep us posted on the results.
Colin |
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| Fuling |
Wow, thanks for the links and the quick reply!
Those zHorns looks interesting, I especially like the fact that the horn mouth is facing forward instead of towards the wall.
They seem awfully small though, only 30" high.
Are there any plans for some bigger horns that fits my drivers somewhere? |
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| derf |
I'm sure Fostex have their own back loaded horn for the fe107e.
If it's just essentially a shielded fe103e, I'm sure there's no problem putting it in the fe103e horn, unless of course the parameters of the driver are entirely different.
If the parameters are similar, I'm sure the Fostex horn would be preferable over the Busch Horn, as it's specifically tailored for the driver you have in mind. |
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| Fuling |
Hi
You mean this one?:
http://www.fostex.co.jp/int/pages/p...e/103e_encl.pdf
Well, lot´s of sharp angles and corners in that one I must say.
I have the tools needed for cutting other angles than 90 degrees
so that design seems a little "primitive"
Thanks for the answer, keep ém coming:D
Cheers |
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| smbrown |
| I have built the mid-sized Z-Horn and been very pleased with it. I use it with a Fostex FE166E. |
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| planet10 |
| quote: | Originally posted by Fuling
It seems that there are several different versions around and at least two different sizes (for 3" and 4" drivers), and People use alot of different drivers in them. Most common are FE 83, FE 103 (Sigma) and FE108, never seen one with FE107E though. |
Have used the FE103A & the RS40-1197 in the Buschhorn IIs, we have a set of FE108ES that will be retrofitted. An excellent design.
| quote: | Originally posted by Colin
The horn shop also features a horn which is similar in layout to the mk 1 Buschorn. It's a commercial product so no design details but the review links should give you a feel for the sound. The TNT Audio reviewer liked it so much he bought it. |
There are only so many ways of folding a horn when using flat sheets to build it... a cut-away of the horn may look similar in layout to a B-Horn but there is no real relation... 1st off the B-Horn is quite a bit bigger. As best i could the attachment illustrates the size difference, the B-Horns are at least 35% deeper as well.
| quote: | Originally posted by derf
I'm sure Fostex have their own back loaded horn for the fe107e. |
The Fostex horns aren't really horns at all, more like a succession of ever larger stepped cylinders.
dave |
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| planet10 |
The 107 should work fine in a B-Horn -- you will just need to tweak the compression chamber...
dave |
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| Fuling |
So they´re worth building? (The Buschhorns)
| quote: | | you will just need to tweak the compression chamber... |
Any idea of how it has to be tweaked?
Bigger or smaller?
If not, how do I calculate it?
| quote: | | so many ways of folding a horn when using flat sheets |
Funny you mention this. I came up with a supposingly great idea just a while ago: Why not use Styrofoam (or whatever it´s called in english) to achieve nice and smooth bends inside the horn?
Or to push it even further: What about a backloaded horn made out of several layers of styrofoam with wooden sides?
Just glue some styrofoam sheets together to get the right thickness then cut out the horn tunnel with a hot Kanthal wire and attach the sides and a baffle for the driver! |
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| planet10 |
| quote: | Originally posted by Fuling
Why not use Styrofoam (or whatever it´s called in english) to achieve nice and smooth bends inside the horn? |
There is at least one commercial product that does essentially this... and it has certainly being done with wooden translam construction -- you'd probably want to fiberglass the cur edges of the styrofoam (and use fiberglass quality construction foam)
dave |
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| planet10 |
looks like a mini-hedland
dave |
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| Fuling |
Yup, the Hedlund horns was a big source for inspiration.
I believe in smooth bends you see:D
Hopefully they´ll play today or tomorrow. |
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| Josephjcole |
I hope these work out for you, they seem to be fairly short horns... how did you come to the demensions you're using? I tried something similar, building my own horn with as few angles as possible, on a somewhat larger scale unfortunately I severly underestimated the amount of bracing required to keep a back horn from resonating:bawling: .... and I have never got it quite right. Anyway, keep us posted as to how they sound.
Joe |
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| Fuling |
I brought them to life yesterday afternoon, and I can tell you that I´ve been listenting to a lot of music the last 24 hours:D
As expected they are a bit weak in the bass, but moving them closer to the back wall helped quite a bit. I´ll try different placements later when the drivers have breaked in properly.
They play down to about 45Hz-50Hz (no measurements, only estimating by listening to sweep tones and stuff)
Bracing...Yes please! Seems like we made the same mistake, these critters vibrates quite a bit more than I had expected.
The question is wheter I should build a new pair using better materials and techniques (mdf/plywood, smoother bends)
or do as I planned from the beginning: use the drivers in open baffles together with a pair of woofers.
These drivers sound excellent in OB´s, but horns are more fun! |
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| Josephjcole |
| quote: | Originally posted by Fuling
Bracing...Yes please! Seems like we made the same mistake, these critters vibrates quite a bit more than I had expected.
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I'm sorry to hear that.... you could certainly put some wooden doweling to stiffen it up, or laminate another layer of plywood for double thick walls. For mine I put in some threaded rods through the sides of them and tightened that down as much as I could with out warping the wood too much, that seemed to work pretty well and is quick and easy, the only draw back is the washers and nuts sticking out of the side of your cabs. I also put a fairly thick layer of fiberglass resin on them, which help somewhat, but not as much as I had hoped.
Good Luck
Joe |
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| Fuling |
Actually I´ve had exactly the same ideas about how to cure the vibration problems!
These horns are just prototypes, I was curious to see if backloaded horns are worth messing with. The answer is yes, so I´m going build a new improved pair as soon as I get the time.
The new ones will probably be slightly bigger (taller and wider)and made of MDF.
I´m not really sure though that I want to mess with this design once more, so my plan B is to build a simpler horn with the mouth facing the back wall or the floor. That should allow a bit of tuning by moving the horns back and forth. |
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| SCD |
Something to help reduce cabinet resonance is to line the inside with tile backing board. There are many brand names, the board is essentially a fiberous concrete board that comes in 1/4" thickness. Spread a wall tile mastic (tile glue) and screw it to the inside of the box. It may be a bit of a challenge in a horn design. Cross doweling is also a good way to make the box dead. Thick side panels of MDF will also help.
Good luck |
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| planet10 |
Exoskeleton ... brace the box (remmber to use irrational ratios) with an exoskeleton... and plywood is by far a better material for building a horn than mdf (because it is stiffer)
dave |
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| Fuling |
The exoskeleton idea is quite interesting.
I can´t really set my mind about how the new horns will be designed, but I´m leaning towards the same basic shape as these ones but slightly taller and made of 22mm MDF
(which should be a big improvement compared to the 19mm particle board that the protos are made of) with some kind of external bracings.
I kinda like the looks of this design and I´m *almost* satisfied with the sound, so why change a working concept?
I hope that a stiffer "box" with a slightly bigger horn will fix the things I´m not satisfied with now.
I´ve also figured out a better way of cutting the angled pieces for the "corners" so that part of the work will hopefully not be such a PITA this time. |
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| Fuling |
After changing my mind about a thousand times (again) I made a pair of horns that with a bit of imagination can be called Buschhorn mkIII. Not that they have much in common with the real Buschhorns except for the way the are folded, but what the heck.
If I´m giong to put a name on them it´ll be something including the word "swan" or maybe "goose". Look at the pic for reference...:D
Well, how do these birds sing?
At the first test run I had them placed very near the corners, assuming that this would be the only way to get proper bass out of them. I was wrong!! I´ve hardly ever heard such boomy bass before, and my first thought was that this project was a complete disaster.
After moving them out of the corners and piling up pillows and stuff behind the opening the bass came down to earth a bit, but the boomy sound is not completely gone yet.
I´ve ordered some damping wool to see if I can treat them internally to get rid of this, probably combined with some absorbents behind the mouth. |
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| Fuling |
I just noticed something on the picture in my previous post:
There are some drawings on the side of the horn that shouldn´t be there. Don´t mind them, they don´t correspond to how the inner walls are placed. |
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| Josephjcole |
| quote: | Originally posted by Fuling
I just noticed something on the picture in my previous post:
There are some drawings on the side of the horn that shouldn�t be there. Don�t mind them, they don�t correspond to how the inner walls are placed. |
Do you have any drawings of how they are folded? Keep us posted on the sound.... any guesses as to what the boominess is from? With more details on the design maybe someone here might be able to help.
Joe |
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| Fuling |
Hi
Well, I don´t have any exact plans of the horns (I more or less designed them at the table saw:) but the folding pattern is roughly similar to the Buschhorns.
The throat area is just above 0,5 of the driver area, mouth is about 9,5dm2. Horn length is 2,1m.
I´ve been experimenting a bit with pillows and stuff behind the mouth and the results are encouraging, the boominess goes down a lot. I guess internal damping will be even more efficient, so I don´t think this will be much of a problem.
The damping stuff arrived today so I´ll try it out and report during the weekend. |
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| Fuling |
I stuffed the last 80-100cm of the horns with damping material today and I´m glad to tell that it worked really good! The boominess is gone for the wind and the tonal balance is better than ever.
I´m going to experiment further with this (gonna try to put some wool in the whole lengt of the horn instead of just the last half/third). Now I at least know that it works! |
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| JVA |
| I also use various amounts of stuffing on my Jordan Traansmission Line project to get rid of the honk. It's amazing how a little bit of stuffing can make all the difference in the sound especially male voices. The stuffing completely eliminated the male vocal honk. |
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| Fuling |
Yup, the stuffing works fine!
I´m going to experiment a bit more withit to see if I can find a good balance between thin and boomy bass.
Right now it leans towards the thin side, especially since I´ve started to damp some walls and corners in the room they play in. |
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