'DOUBLE S HORN'

Still playing around with a double 18 horn concept....

Folding similar to 186 horn with letterbox opening like wsx

Looks cool. I don't know why but Amano springs to mind

Just so that I can give some proper advice, what is your intentions with this design?

If this prototype works out, you should really make one as close as possible to identical with the flat panels to a/b. It could settle a lot of debates.

Not telling you what to do, just living vicariously. My wife is only up to about 1 or 2 speaker projects per year.

Dref wrote: Looks cool. I don't know why but Amano springs to mind

Just so that I can give some proper advice, what is your intentions with this design?

45hz- 150hz in group of 4. I want to keep the throat looser and rear chamber bigger (than the 1850 horn for instance) to accommodate 'less expensive' drivers/ drivers with less stiff cones etc.
What I am most unsure about is how to start the horn. In the sense of- how big to make the letter box -being as it is going to have two drivers firing into it etc.

Maybe you could place a small panel or a wedge shaped dead space between the two drivers so that they don't fire directly at each other. It would divide the throat in half coming forward from the back panel, and past the letterbox opening, but then merge before it rounds the first corner but after the edge of the letter box. That way the force coming straight off the front of the cones would be forced harmlessly down the horn path, instead of slamming into the driver opposite. The compression ratio might be easier to calculate as well.

bgrade wrote: Maybe you could place a small panel or a wedge shaped dead space between the two drivers so that they don't fire directly at each other. It would divide the throat in half coming forward from the back panel, and past the letterbox opening, but then merge before it rounds the first corner but after the edge of the letter box. That way the force coming straight off the front of the cones would be forced harmlessly down the horn path, instead of slamming into the driver opposite. The compression ratio might be easier to calculate as well.

I thought about that too....but the labhorn and BT7 drivers fire towards each other, there must be a safe way to do it......

There's probably no need for the tapered part of the throat. There will be a lot happening regarding pressure with two speakers facing each other, and by having that type of throat, you will be increasing the resistance. When doing these kind of throats, I have always had an outlet to the "LetterBox" that relates to the size of the Box and expanded from there.

If it has to be a double 18" horn then I think it would be best to go for a short horn, maybe something with the same layout as the old straight Martin and ASS bass horns:


or a horn like:
hornplans.free.fr/hb1805c1.html

But in my opinion it would make more sense to use 2x15" drivers.(Keep in mind the surface area of two 15" is around the same of a 21")

A bandpass horn could also be an option if it has to be 18" drivers.
An advantage of using a bandpass horn is that they are easier to get to work with "softer" drivers than a front loaded horn.

tony.a.s.s. wrote: There's probably no need for the tapered part of the throat. There will be a lot happening regarding pressure with two speakers facing each other, and by having that type of throat, you will be increasing the resistance. When doing these kind of throats, I have always had an outlet to the "LetterBox" that relates to the size of the Box and expanded from there.

Please explain 'outlet' to letterbox.....

Just like that, and of course, it comes in different shapes and sizes according to the mouth opening itself.My latest Horn Cab which has a 21" speaker has a square mouth in front of the speaker, with the idea that the pressure in front of the cone will be more even.