Buschhorn mkII

[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

[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

[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?

[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.

[Fuling]

Hi

You mean this one?:
http://www.fostex.co.jp/int/pages/pr.../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

Cheers

[smbrown]

I have built the mid-sized Z-Horn and been very pleased with it. I use it with a Fostex FE166E.

[planet10]

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.

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.

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

[planet10]

The 107 should work fine in a B-Horn -- you will just need to tweak the compression chamber...

dave

[Fuling]

So they´re worth building? (The Buschhorns)

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?

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!

[planet10]

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