Not sure how to make a front/back loaded horn work ?

[audioaction]

Here’s the situation. I've built a pair of back loaded cabinets for the Fostex 206E according to the recommended Fostex design http://madisound.com/pdf/fostexcabs/206e_encl.pdf. After many hours in the shop pouring my blood sweet and tears into getting the internal foldings right I've possibly completed the worlds most boring box with a square hole in the front. Anyways I've seen designs like the beauhorn http://www.beauhorn.com/pages/frame.html.and would like to try to attempt to add a mid front horn to the existing Fostex design. I've almost no experience in designing horns, so my question is what do I need to take into consideration when designing a front horn for a speaker that is all ready mounted in a back loaded horn? I've done some searching, but can't quite find what I'm looking for.

[Taperwood]

Define boring.

Is it the sound or the looks, or both, or something else?

[audioaction]

Well I haven't recieved the drivers in the mail, and can't quit starring at these giant shoeboxes I've made. I like sound of mid horns alot, so I thought it would be ineresting to go ahead and incorporate one into the existing cabinets. I guess it boils down to that I don't want to be stuck with your run of the mill back loaded horn speaker ( even though thats what I intended to do in the first place.)

[Taperwood]

I see I guess my advice is for patience. Get the drivers and listen to them for a couple of weeks. Then decide if you like them or not.

I'm sure someone then can help you design a horn, if that's what you really want, but I would suggest a prototype or mockup on your first efforts, just to see what's what.

Doug

[wixy]

Im interested to know, just how do people come up with a back/front loaded horn design?

[big_kahunah]

www.quarter-wave.com
http://melhuish.org/audio/horn.html

[audioaction]

I've already seen on Martin King's site that he will be coming out with a section on a combined front/back type horn. But I was wondering if there is anything else out there, or is there anyone who's tried this before. I know roughly how to design a horn, but I'm wondering what parameters will be affected when combining the two ?

[ghpicard]

Basically, when you have a bass BLH, you reinforce the drivers uptilted frequency response, balancing it if the design is right.
If you add a front horn, you unbalance it again, as you reinforce the mids. The highs are kept as they were before due to the beaming characteristic of the driver.

OTOH, I have a couple of FE108EZ in Fostex recommended FE108Z BLH side firing horns, and added a small conical horn to compensate for a dip around 1000Hz. No measurements, no nothing. Just ear adjustment and a little googling around. And I did my FH from cardboard. It works fine, but I did this after about around 100 hours listening. If in the future I decide the sound became unbalanced (or my ears do) I can always take the contraptions out of the front baffle, and that's it.

I would add to reinforce Doug's advice for patience that driver break-in for Fostexes is quite long. Hundreds of hours for the ESigmas...

Gastón

[alejo]

Hello Gaston, please if you want contact me to talk about F108eZ I build tube amps and want build one BLH, but I never lisent one.
alejo08101974@ciudad.com.ar

thanks

[e-side]

Originally posted by audioaction
I know roughly how to design a horn, but I'm wondering what parameters will be affected when combining the two ?

You should read Dinsdale's article, he describes a design consisting of one driver, both sides attached to a horn.

http://www.volvotreter.de/dl-section.htm see bottom of the page.