Horn design?

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frugal-phile™
Joined 2001
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There is lots of information here & on the fill-range forum, but it is going to take some study. Start bt looking at what other people have done. The frigal-horn would be a good plac to start. Google Dinsdale... i know someone is hosting the pdfs i scanned -- not a 100% up-to-date but a really good place to start. Hohn has a horn design section on the single driver site.

dave
 
As Dave says, it's not as simple as all that. WinISD this is not. It takes a lot of study. I do hope you like math. Because if you don't, you're going to need a drink. Unless you're really interested in horns, and desperately wish to design one of your own, you might be better off using an existing design, at least initially, while you're reading about them, and to have something to compare your own future design to.

The Dinsdale papers Dave refers to are here: http://www.volvotreter.de/dl-section.htm It'd also be a good idea to read everything Martin King has written on the subject: www.quarter-wave.com which shows exactly what's happening in terms of the physics involved, and also the introduction to horns on the Single Driver Site: http://melhuish.org/audio/horn.html

The Big Gun in horn design theory is Leach's paper http://users.ece.gatech.edu/~mleach/papers/HornPaper/HornPaper.pdf This is one of the most important papers ever written about horns, and contains a number of very accurate equations which, if you plug your desired numbers into them, will give a ~ideal horn which you can fudge into a BLH.

So much for the easy part. Assuming you've gone through this and figured out what to plug into the equations (best entered into a spreadsheet), which is actually pretty easy once you get used to it, you come to the tricky parts of size reduction, blending TL and horn action etc. It's possible to do this empirically, but better is to model the response of the theoretical / mathamatical horn you've just designed for your driver in a program like Martin King's MathCad worksheets, available for a nominal fee from his site, er, cited, above. With this, you can adjust the horn profile and optimise the response of your compromised horn (unless you want a pathlength of 24ft and 40ft^2 mouths ;) ). How you decide to fold it up into a cabinet of course is another science / art in istself & needs to be done carefully, to minimise problems & maintain the flare-rate. Fun isn't it?
 
frugal-phile™
Joined 2001
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After posting above, i ended up at this wikipeadea entry which will give a bit more background, and has links to further study.

Just keep in mind that there is liley as much misinformation, or parital truth out there as solid information -- not because the author is trying to mislead, but because the whole science of horns is moving from mathematical approximations to -- with tols like Martin's & Ron's -- being able to do a virtual study on the real (modeled) effects of various schemes as opposed to just theoretical backed up by build & try.

Scottmoose said:
The Big Gun in horn design theory is Leach's paper http://users.ece.gatech.edu/~mleach/papers/HornPaper/HornPaper.pdf This is one of the most important papers ever written about horns, and contains a number of very accurate equations which, if you plug your desired numbers into them, will give a ~ideal horn which you can fudge into a BLH.

One has to keep in mind that Leach is only valid for those cases that satisfy his assumptions... one of which is that your goal is maximum efficiency. In a BLH this is not always the case as a balance with the IB radiation of the speaker further up needs to be considered.

dave
 
Good point Dave. Blending the horn's upper cut-off into the drivers IB response and matching the sensitivies, as well as extras such as using the boost from the horns to compensate for baffle-step diffraction is a whole extra set of things to consider...

As you see Lemans -no one answer. And Dave and I work together designing horns!
 
Scottmoose said:

As you see Lemans -no one answer. And Dave and I work together designing horns!

Hello!

I hope you don't work in the same horn... one on each side !!!
(I was a kid 20 years ago and I didn't know what I was doing with no software, imagine now...)
Hei, lemans23 I am not saying it takes 20 years to read... you go little by little with the most important and doing mistakes.
 
lemans23 said:
I did man, I searched. I can't find somewhere that says HOW to design one.
MJK's Quarter Wave Site has some info in his "Front and Back Loaded Horn Theory Derivation" area on how to design (ie. formulae to work out lengths, etc).

There's a couple of things on the Single Driver Website, including an Exponential / Hyperbolic Contour Calculator. Plus a lot of information.

Either or both of these would give you enough information to design and build a horn loudspeaker that would probably sound really bad (OK, you might be lucky :))!

Better, for your first attempt, to emulate someone else's success by using a proven design. Or, you could purchase MJK's Mathcad sheets (from the Quarter Wave site) and try to model your own - with a little more success.
 
At first I thought you were talking to me, I am Dave as well. :)

I will look into your websites. Yep, I'm down for the math, hope to study ME in college with specialization in acoustics/noise control, so I'm always down for some physics. Dunno if an 18 yr old's high school physics will be sufficient, but I'll try my best. Thanks again!
 
frugal-phile™
Joined 2001
Paid Member
lemans23 said:
At first I thought you were talking to me, I am Dave as well. :)

In his best Cheech Marin voice, "Dave's not here, man"

I will look into your websites. Yep, I'm down for the math, hope to study ME in college with specialization in acoustics/noise control, so I'm always down for some physics. Dunno if an 18 yr old's high school physics will be sufficient, but I'll try my best. Thanks again!

The math is mostly algebra... i started in on this stuff in high school...

dave
 
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