My first horn - Page 2

planet10 · 24th December 2012, 07:37 AM

Quote:

Originally Posted by dtproff

can you tell me what BVR stands for?

Big Vent Reflex.

Do a search here on replikin... that is th eBVR that yours resembles.

dave

Scottmoose · 24th December 2012, 08:21 AM

Replikon

+1 to what GM said. There is something very wrong with that posted MathCAD data.

dtproff · 24th December 2012, 01:36 PM

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

xrk971 · 24th December 2012, 02:03 PM

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.

GM · 24th December 2012, 03:17 PM

Quote:

Originally Posted by dtproff

Thanks guy's.

You're welcome!

Just the driver specs, horn design parameters.

GM

dtproff · 25th December 2012, 01:10 AM

Here they are. No laughing now. I am certain I blew it in more than one spot but I promise I am trainable!

Tony

dtproff · 25th December 2012, 01:13 AM

I also re-entered the parameters in Hornresp and got different results. I will say the system volume in Horn response is 76L and I modeled 75.

Tony

dtproff · 25th December 2012, 01:14 AM

BTW... I had to change the upper throat in Hornresp from a 1" opening to 2" (and 10" wide).

Tony

GM · 25th December 2012, 01:56 AM

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

dtproff · 25th December 2012, 02:03 AM

Quote:

Originally Posted by GM

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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24th December 2012, 08:21 AM	#12
Scottmoose diyAudio Member Join Date: Mar 2005 Location: UK	Replikon +1 to what GM said. There is something very wrong with that posted MathCAD data.

24th December 2012, 01:36 PM	#13
dtproff diyAudio Member Join Date: Oct 2008 Location: Plano, TX, USA	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

24th December 2012, 02:03 PM	#14
xrk971 diyAudio Member Join Date: Oct 2012 Location: Virginia	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.

25th December 2012, 01:14 AM	#18
dtproff diyAudio Member Join Date: Oct 2008 Location: Plano, TX, USA	BTW... I had to change the upper throat in Hornresp from a 1" opening to 2" (and 10" wide). Tony