Arash Posted November 12, 2014 Share Posted November 12, 2014 (edited) actually we are working on a folded horn bassbin (inspired by LS) but as this is the first folded horn we are working on, I thought I may get some help calculating/simulating the design in Hornresp to avoid try and error. we hope after completion, all details will be available for everyone free to personal use. this is what is rightnow on the drawing table: where should I start if I want to check it in Hornresp? horn length? throat area? mouth area? is there any tutorial of Hornresp for a novice? I hope we can simulate and tweak this in Hornresp and check the result with Clio. btw, the plan has much more details I tried to keep thing simple. this is the full detail: Edited November 12, 2014 by Arash Quote Link to comment Share on other sites More sharing options...
Arash Posted November 12, 2014 Author Share Posted November 12, 2014 (edited) here is a well explained tutorial I'm reading now. I hope if anything is inarticulate to me I'll check here http://www.diyaudio.com/oldwiki/index.php?page=Hornresp+Help Edited November 12, 2014 by Arash Quote Link to comment Share on other sites More sharing options...
Arash Posted November 12, 2014 Author Share Posted November 12, 2014 which horn type should I choose for a folded horn like this? Hornresp provides Conical, Exponential, Tractrix, Parabolic,... Quote Link to comment Share on other sites More sharing options...
Arash Posted November 12, 2014 Author Share Posted November 12, 2014 I think folding a horn will decrease the total length of the horn but also affects the horn sectional area. correct me if I'm wrong Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 12, 2014 Share Posted November 12, 2014 If you can't get any help here you should try the AVSforum, DIY subwoofer section. There are several members there that model and design subs with this software. 1 Quote Link to comment Share on other sites More sharing options...
djk Posted November 13, 2014 Share Posted November 13, 2014 "I think folding a horn will decrease the total length of the horn but also affects the horn sectional area. correct me if I'm wrong" Wrong. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted November 13, 2014 Share Posted November 13, 2014 Here is some stuff I have figured out over time... I am by NO MEANS even close to an expert or authority. This is just some stuff I have learned that may be helpful. There are different theories on how to correctly measure the length of a folded horn, but a folded horn is the length of a non-folded horn that has been folded. I like to measure from the centerline of each section to get horn length. A horn of this type will be tuned at a quarter wavelength. If you want to tune to 55Hz for instance, then you would take the speed of sound divided by 55Hz then divided by four. 1,125 / 55 / 4 = 5.1ft.. You can discover the tuning frequency of an existing horn by measuring the length, multiplying by for and dividing that into 1,125. [eg: 1,125 / (6.5' X 4) = 43.3Hz] There are also half wavelength horns and even huge full wavelength horns. The tutorial I like best is here: http://www.hometheatershack.com/forums/diy-subwoofers-general-discussion/36532-hornresp-dum-hmm-everyone.html 2 Quote Link to comment Share on other sites More sharing options...
djk Posted November 13, 2014 Share Posted November 13, 2014 Tell me the driver model and the desired curtoff frequency and I will design a horn for you. You can then load the template into Hornresp and try different drivers, modify the dimensions, etc. Quote Link to comment Share on other sites More sharing options...
djk Posted November 13, 2014 Share Posted November 13, 2014 Quote Link to comment Share on other sites More sharing options...
drboar Posted November 15, 2014 Share Posted November 15, 2014 I have been playing around witha LS type bass horn. The throat extends into the dog house and the driver is a 12" But it is still a short bass horn with the same mouth area as a LS. In my horn at least the basic response is set by horn lenght and mouth area. Different flares and chamber sizes does not make a big difference. These things can be used to change the knee above the high pass drop off. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted November 15, 2014 Share Posted November 15, 2014 Does Klipsch or anybody make a Tractrix bass horn? Would it have the same advantages as a tweeter Tractrix? Quote Link to comment Share on other sites More sharing options...
Chris A Posted June 12, 2015 Share Posted June 12, 2015 (edited) Does Klipsch or anybody make a Tractrix bass horn? Would it have the same advantages as a tweeter Tractrix? Knowing this is an older thread, I just saw this question... An answer: the KPT-305-MB is a modified tractrix midbass horn that is shorter than a real tractrix horn by about a factor of three, but it has all the advantages of a tractrix profile. It's a very good horn. (Why there haven't been other tractrix bass bins is found below.) The advantages of tractrix are many since the tractrix is basically the most efficient profile for a horn (it assumes spherical waves internally instead of flat wave fronts like the exponential horn does). But one thing that you need to remember: you cannot decrease the size of the horn's mouth by truncating the mouth at less than 90% of its full 90 degree expansion without significant loss of horn performance. That is the one constraint that you can't cut corners with tractrix. Read the 2/1981 Speaker Builder article "The Tractrix Horn Profile" by Dr. Bruce Edgar for more information. There isn't a lot of information out there on the tractrix profile. EDIT: See Bruce Edgar's comment on tractrix bass horn throat reactance issues here. Chris Edited June 12, 2015 by Chris A Quote Link to comment Share on other sites More sharing options...
moray james Posted June 12, 2015 Share Posted June 12, 2015 (edited) here is a tractrix bass horn designed by the late Ernst Georg Beck http://www.egbeck.de/expo15.htm yes it says expo but this is a tractrix horn design never the less. Edited June 12, 2015 by moray james Quote Link to comment Share on other sites More sharing options...
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