My first horn

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I have lurked here for years and finally decided to get my hands dirty. The wife capitulated and has given me a space to build a full range horn (as long as it looks pretty and I make the matching entertainment center to go with it).

I have a licensed copy of MLK back loaded horn and I believe I have entered things correctly.

What I am hoping for is that someone can look at this and tell me if the horn response looks right (or maybe someone has a different calculator for comparison).

The inspiration for the design came off the German site Yellowplay

I really want to build, test, and (better yet) understand my design so if you guys wouldn't mind looking this over and telling me what you think I would appreciate it.

The speaker will be the FE126En.

Tony
[image][/image]
 

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The design is very simple not too many turns, which is good. Kind of reminds me of the Half Chang, which appears to sound very nice - as expressed by MJK himself. I can't see the simulation plot clearly, the image is very low res. Does it show the bass extension down to 30 Hz? If so, that is surprising that horn length is only 31 inches and achieves this.
 
Attached is a more detailed picture.

I believe the key to the driver response is the large compression chamber behind the 5" driver. The Yellowplay site kind of intimates that when you look at the first and second response plots they offered.

I really appreciate everyones response. I haven't done one of these so any mistakes avoided will save me time.

Tony
 

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Your combined SPL curve is flat - very nice. I don't understand why the level is only 74 db though. The FE126En is a pretty efficient driver. Or are you only simulating at low power on purpose? Even with compression chamber, I am surprised that this design goes down to 30 Hz before rolling off.
Good luck with it. In case you haven't seen the foam core or Cornu threads, this driver would probably work well in a Cornu which is an easy to build BLH that has high WAF.
 
The foam core approach offers some appeal but unfortunately the wife only gave me one little area with which to put this thing. I am in the corner of the room just past her sowing table. I was told quite emphatically that I must live withing the allocated space and that any deviation from there would me being relegated back to the garage. Oh well, so much for for being the master of my domain!

As to the power level... the MLK spread sheet is for 1W input power.

The entire room plot looks pretty lumpy which is why I was turning to the forum for help. Not sure if I was doing something wrong there or not.

Tony
 
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The foam core approach offers some appeal but unfortunately the wife only gave me one little area with which to put this thing. I am in the corner of the room just past her sowing table. I was told quite emphatically that I must live withing the allocated space and that any deviation from there would me being relegated back to the garage. Oh well, so much for for being the master of my domain!

As to the power level... the MLK spread sheet is for 1W input power.

The entire room plot looks pretty lumpy which is why I was turning to the forum for help. Not sure if I was doing something wrong there or not.

Tony

That's the nice thing about the Cornu's - they don't take up any floor space but hang on the wall, do you have wall space allocated by SWMBO? I did not realize the lumpy plot was the combined, I thought that was horn output and blue was combined room response. Yes, please show inputs and particularly how the room was modeled.
 
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Thanks guy's.

Can I post a PDF of the MLK MathCAD file I used or do I just feed you the parameters?

The plot I posed was the one called Woofer and Terminus far field response. I do not believe that one has any of the room effects in it. The room model is down at the end of the file.

Tony

Tony
 
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That makes sense that the terminus output is going to have dips and peaks as those are the characteristics of the horn and it resonances. Adding stuffing along the line and in the compression chamber helps to smooth things out if you haven't done so already. The integrated room response with driver + terminus output should be smoother. A pdf file can be uploaded or you can paste images directly.
 
As I suspicioned, the driver specs are somewhat whacked, especially Fs.

Fs = 83 Hz
Qes = 0.33, which should auto calculate a higher Qts
Vas = ~7.9115 L based on Fs, Sd, Mms
BL = ~5.6444 based on Fs, Mms, Re, Qes

In HR, it should look like this, which is fractionally different due to more rounding off, but acoustically inconsequential:

GM
 

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As I suspicioned, the driver specs are somewhat whacked, especially Fs.

Fs = 83 Hz
Qes = 0.33, which should auto calculate a higher Qts
Vas = ~7.9115 L based on Fs, Sd, Mms
BL = ~5.6444 based on Fs, Mms, Re, Qes

In HR, it should look like this, which is fractionally different due to more rounding off, but acoustically inconsequential:

GM

Thanks... I'll go back and rework things.

I appreciate it.

BTW...

I appreciate you taking the time to respond. If I just replicate what others have done I don't learn.

Again... I appreciate your help.

Tony
 
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