Collaborative Tapped horn project

Ok, thanks very much, if I hit "calculate" it gives the correct graph. (I've never noticed a difference at all between the wizard screen and the "calculated" response, and so I haven't hit "calculate" for weeks now)

I don't understand why there is a difference. Although you clearly know why (as quoted below) I don't understand this statement.

The Wizard will give the correct response until you change S2 from Fixed to Variable.

How do you change S2 to fixed to get the correct response? What's going on here?

(Has this been covered before? This is all new to me...)
 
Re: Post #2949

Hi Oliver,

tb46 said:

Thanks, but I must say that I did not thought it would be so difficult... I assume all first timers say this ;).


tb46 said:
Question 1: Use some inexpensive wood like particle board or OSB and keep one side removable to be able to make internal modifications. I would keep S1 larger than Sd/3. You only need a value for Atc if you are using a chamber between the driver and the horn, and I assume you added Rg for speaker wire.

Ok, I think I understand all of that.

tb46 said:
Question 2: If you keep the distance L12 between 0.1cm and the driver cone radius, the upper end cleans up a bit, ....
Ok, pushing to the extreme, L12 = 0 means that the driver axis is at the throat (option 1 below) or the driver side is at the throat (option 2 below).

Horn%20options%20260209.png


In your simulation, you do have the first part of the horn with only a little increase in section and then the other part increases more.

Is it on purpose ?
Can you elaborate a bit on what this set up changes, because it would be a lot harder to build, wouldn't it ? (though the Danley tower, not sure the model possiblu allows for that).

Many thanks again for your reply.

Cheers.
 
just a guy said:
How do you change S2 to fixed to get the correct response? What's going on here?

(Has this been covered before? This is all new to me...)

This time, maybe I can help :).

In th wizzard, you have a 3 drop down at the bottom of the window. I think it is in the last one where you can select this.

Actually I am not 100% sure now and I do not have HR handy... So maybe I helped, maybe not...
 
Yeah, it was another case of an older version of hornresp. I had the newest one downloaded but was having serious troubles getting it installed. Tried it on a different computer and all is well now. I guess I need a windows reinstall on the laptop I usually use, as I'm having trouble every time installing the newest hornresp.

Oh well, another half page wasted on my inability to keep up with you crazy kids.
 
Post #2964

Hi Jean-Michel,

Hornresp does not allow for a 0 (zero) in the L12 entry field, 0.1 cm is the minimum. If I remember correctly iand suggested adding the fourth horn section to allow for different frequency tuning in the middle of the horn. You seem to be doing fine with the simulation tool. Anyway, try to read through this thread, all the information is in there, including the conversion of Hornresp files into AkAbak. I know it will take some time to work all the way through this, but, it is worth it.

Regards,
 
G'day MaVo

Looking at the graphs above, I'd eyeball a difference of ~2dB on the amplitude of the 2nd, 3rd and 5th peaks. The 4th is way down. I should have done some lining experiments on this box, but I built it for a friend and with the DCX2496 controlling the system, the desired response could be easily achieved. That measurement has a resolution of ~1Hz and will have no problems showing the true amplitude and Q of the peaks in the response.

Cheers

William Cowan
 
Post #2970

Hi Jean-Michel:

Finally back from work. To add to your options 1 and 2 I drew up a few more throat options, see attachment. 1a/b/c and your #s 1 and 2 should all give similar results. The dual driver push/pull a la JLH is an interesting example of the possibilities.

As your main interest seems to be hometheater take a look at the following references (that will be my first building excursion into tapped horns, using the inexpensive (oh well, cheap :)) MCM 55-2421):

The diyaudio Forum "Double Driver Tapped Horn" thread:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=136282&perpage=25&pagenumber=1

rmk has created a very nice reference thread on his experiences with tapped horn hometheater subwoofers:
http://forums.audioholics.com/forum...ad.php?p=492319

aceinc decided to document his build in another forum:
http://www.hometheatershack.com/forums/diy-subwoofers/16807-tapped-horn-build-th-spud.html
There he provides some comparisons to other subwoofers he has build. Definitely recommended reading.

JLH has build and documented a nice dual driver tapped horn layout, that uses a small chamber between the woofers and the throat:
http://www.diyaudio.com/forums/show...778#post1711778

Regards,
 

Attachments

  • th_some throat options.pdf
    7.7 KB · Views: 172
At the very least you need to input a value for L34. If you type it in but it reverts back to 0, just double click the L34 input box and a pop up screen will allow you to input the info and then it will stick. (HINT - almost every input box has a VERY helpful pop up if you double click it)

Also, you have a value entered for atc (area of the throat chamber) but no value for volume of throat chamber. If you want a throat chamber, fill in a value for vtc, if not, delete the value for atc.
 
just a guy said:
If you type it in but it reverts back to 0, just double click the L34 input box and a pop up screen will allow you to input the info and then it will stick.

Hi Kevin,

Further to just a guy's comment, L34 will only revert to zero if the segment flare type is not specified along with the length value. The flare can be selected by double-clicking the L34 label, or by pressing the C or E key when the L34 input box is highlighted.

Note that both a flare type and non-zero length need to be specified for the values to "stick".

Kind regards,

David
 
Kevk said:
Can someone please tell me what I'm doing wrong with Hornresp? I've entered values that I've seen posted a few posts back, but my input dialog box looks a little different and the labels don't match. I have version 21.

Thanks,
Kevin

Kevin:

I'm not sure exactly what you are asking, but there are a couple of issues in your parameters. First, I think you need to set your sections to conical (Con) by clicking on the L12, L23 and L34 dialogs. Secondly, you haven't added a length value for L34 even though you have added an area for this parameter. You should fix these. Also, you don't need to worry about any values below the "BL" parameter line. These are only if you also want to add a rear chamber or if you want to simulate a closed or vented box.
 
Thanks everyone for the help. While I'm starting to grasp the concepts of the tapped horn, I still have long way to go with all of the lingo. I'm sure I'll have more questions as I go along. Has anyone thought of starting a document that could capture all of this wonderful knowledge that has been shared here, kind of like a Design Criteria for Tapped Horns? Everything from recommended driver parameters, labeled diagrams (like ones showing input fields in Hornresp that correspond to various parts of the drawing), construction materials (do's & don'ts), etc. This post is a wonderful resource but it takes quite a while to go through all 120 pages (which I have done) and gleen bits and pieces here & there. Keep up the good work & I'll be back.

Kevin