My Ultimate Fostex FE206E Horn!

[brsanko]

It flares both ways. The front horn is more for the midrange than high frequencies though.

 

[Cal Weldon]

I can see almost the full cone on the horizontal plane and almost nothing on the vertical. If that is a representation of what it is to look like, you've got the horn going the wrong direction.

 

[brsanko]

Okay I guess you're right I did draw it that way. I really don't know much about dispersion, but I intended to make the throat of the horn square. The horn actually effects the band from about 200hz to about 5k so I don't know if that changes anything.

 

[brsanko]

The model was just an approximation to give me an idea what the design would look like. I didn't really even measure anything. I am going to redraw the whole thing soon. I guess I'll have to do some research on how horn shape effects dispersion before I build it. Any suggested readings?

 

[Bill poster]

At higher frequencies, horizontal dispersion comes from a vertical source. Look at ribbon tweeters and line arrays. Maybe I am missing something in the drawing. In a horn, to have horizontal dispersion you have to have horizontal flare. I see only a vertical flare.

Out of interest, why are PA horn tweeters horizontal?

 

[Cal Weldon]

Of the top of my head I would consider emulating the Altec approach and expose 1/2 of the driver in a vertical horn flare as done in the A7 and a slope not a flare, say 20 degrees on the top and bottom and a round over at the baffle.

 

[speakrsrfun]

Tractrix Style flare?

 

[brsanko]

I guess I'm more interested in learning the science behind it and making my own design than just emulating someone else's design just 'cause it works.

 

[Rick J. B.]

There's no such thing. Just different sets of compromises. You pick those that best suit your particular requirements and accept the fact that one universal perfection doesn't exist, in compound horns or anything else in this life. More's the pity, althogh it would probably make life less fun.

Scott, of course, I guess I worded that poorly. What I meant to ask simply out of curiosity was what was your favorite, or to your ears what was the best horn design for this or a similar driver.

 

[ultrakaz]

I guess I'm more interested in learning the science behind it and making my own design than just emulating someone else's design just 'cause it works.

Yes, that is the beginning of most great designs, especially the ones that are revolutionary. Recently, with advanced modeling software (Martin King) really great designs are available or old designs are proven to be great (Fostex/Nagaoka). Having said the above nothing beats actually building, measuring, tweaking and listening to your own design. So, you are off to a great start. This goes without saying but the payoff is in the process. And you can listen to your music too. Good luck.

 

[planet10]

for the (defunct) FE206E

Note that the primary North American Fostex distributor no longer has any FE206e. They are now shipping FE206En (not to be confused with the FE206eN i have been shipping for some 2 years now). Until we get some in the field measures we don't know how close the new driver is to the old one.

dave

 

[planet10]

The horn actually effects the band from about 200hz to about 5k

A horn is typically good for a maximum of 3.5-4 octaves.

dave

 

[Scottmoose]

Scott, of course, I guess I worded that poorly. What I meant to ask simply out of curiosity was what was your favorite, or to your ears what was the best horn design for this or a similar driver.

I dunno, and that's a fact. I've never really thought about it as I generally avoid terms like 'best', or comparisons between enclosures unless they are designed with exactly the same remit. And it will depends on room, requirements, amplifier, material, personal taste & so on. For e.g., I could say x sounded fantastic in y situation, but if you plonked it down in z situation, it may not work so well. There are a few very good enclosures out there, and no doubt more to come (the new 206En model should be close enough to work in boxes for the old 206E). YMMV as ever.

 

[brsanko]

A horn is typically good for a maximum of 3.5-4 octaves.

dave

In that case 200hz-2khz then. I was guessing at the top end.