Hornresp - Page 176 - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 13th March 2011, 05:43 AM   #1751
diyAudio Member
 
Join Date: Jun 2007
Quote:
Originally Posted by soho54 View Post
If a rear chamber port is tapped into the forward horn somewhere, instead of exiting from it's own external enclosure orifice
Hi soho54,

Thanks for this - it would seem that I completely misunderstood Dan's original question :-).

By "when the port is in the throat of an OD horn" I automatically assumed that he was referring to the Ap1 throat chamber port parameter, but I think you are probably right and that he was actually referring to the Ap vented rear chamber port parameter, but with the port output feeding back into the throat of an OD horn. As you have quite rightly pointed out, Hornresp cannot simulate such systems.

Kind regards,

David
__________________
www.hornresp.net
  Reply With Quote
Old 13th March 2011, 05:54 AM   #1752
diyAudio Member
 
Join Date: Jun 2007
Default Hornresp - Minor Update

Quote:
Originally Posted by David McBean View Post
I will rectify this in the next release.
Hi Everyone,

The Hornresp Help file has been changed - hopefully the description of the path length difference parameter in the Combined Response section is now a little less confusing. My thanks to Lars for highlighting the ambiguity.

Not that it really matters much, but I have also taken the opportunity to add Cancel buttons to both the Find and the Phase Offset Delay Correction tools :-).

The new release is Product Number 2830-110313.

Kind regards,

David
__________________
www.hornresp.net
  Reply With Quote
Old 18th March 2011, 10:53 AM   #1753
3GGG is offline 3GGG  Australia
diyAudio Member
 
Join Date: Mar 2010
Hi David

When exporting data to try and plot a Tractrix horn design what do I select in the following screen?

Note:I havent changed the data on the Export page.

Is it as simple as entering the S1 and S2 from the earlier design? What do I do about the con, exp or uni choice?

Thanks again for your help.

Gregg
Attached Images
File Type: gif ScreenHunter_03 Mar. 18 21.19.gif (9.5 KB, 196 views)
File Type: gif ScreenHunter_02 Mar. 18 21.19.gif (9.8 KB, 193 views)
File Type: gif ScreenHunter_01 Mar. 18 21.18.gif (16.7 KB, 191 views)
  Reply With Quote
Old 18th March 2011, 10:23 PM   #1754
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by djn View Post
Thanks Weltersys. Not concerned with wasting wood. A friend of mine owns a saw mill and I can get as much pine and oak as I need.

OK, when I get the graph and it shows high and low rolloff, should I be crossing over to a mid at the point of the high rolloff, or is it just a test and see type deal?
Although I have much gratitude to David for Hornresp, no simulation can account for all the variables, so test and listen to the real deal.

Crossover design is also outside the range of what this thread is about, but simply put, generally you want the crossover point a ways below the high rolloff, as most speakers will not be nice and smooth up there, and peaks in the response can be heard even if they are an octave away using a 24 dB per octave acoustic crossover. With 18, 12, or 6 dB per octave crossovers, smooth response must be extended much further.

Passive crossover design makes cabinet design look like child's play.
Even using digital active crossovers and dual FFT test equipment (and good ears and a good meat processor), good crossover design is very tricky.

And if the crossover design is off, the wonderful cabinets one can design using Hornresp may end up sounding like hammered dog poo.
  Reply With Quote
Old 19th March 2011, 05:53 AM   #1755
diyAudio Member
 
Join Date: Jun 2007
Quote:
Originally Posted by 3GGG View Post
Is it as simple as entering the S1 and S2 from the earlier design? What do I do about the con, exp or uni choice?
Hi Gregg,

The 'Horn Cross-Section Dimensions' input form allows you to specify the dimensions at each end of a horn segment, assuming that the cross-sectional areas are either rectangular or square at those points.

For the example you have given, S1 = 20.30 and S2 = 6000.00.

By default Hornresp assumes square cross-sectional areas for the exported data, so that:

At S1 the height = 4.51 (square root of 20.30) and the width = 4.50 (20.30 / 4.51)
Similarly, at S2 the height = 77.46 (square root of 6000.00) and the width = 77.46 (6000.00 / 77.46)

The S1 and S2 height values can be changed as required if the cross-sectional areas are not square. The width values will then be altered automatically to maintain the correct cross-sectional areas.

The Con, Exp or Uni 'Width Flare' option specifies how the width increases along the length of the horn segment - this then also influences how the height increases. The Uni option causes the horn segment to flare uniformly in both the width and height directions. This option is most likely the one that you will want to use, I expect.

The radius values for a circular cross-section horn segment are also automatically included in the exported data list.

The attached screenprint shows the plotted exported data for your example, using the default square cross-sectional area values and the Con option. The pink trace shows the width expanding "conically", the blue trace shows how the height changes because of the conical width flare, and the red trace shows the radius of an equivalent-area axisymmetric (or circular cross-section) horn segment.

If you choose the Uni flare instead for a square cross-section horn segment, then the pink and blue traces will be the same.

Kind regards,

David
Attached Images
File Type: png Tractrix.png (34.0 KB, 167 views)
__________________
www.hornresp.net

Last edited by David McBean; 19th March 2011 at 06:04 AM.
  Reply With Quote
Old 19th March 2011, 06:32 AM   #1756
3GGG is offline 3GGG  Australia
diyAudio Member
 
Join Date: Mar 2010
Thanks David

I will be building round plywwod horns, made of lots of rings of plywood turned up on a diy lathe.

I will try and process your response:-)

Big thanks again.
  Reply With Quote
Old 19th March 2011, 07:53 AM   #1757
diyAudio Member
 
Join Date: Jun 2007
Quote:
Originally Posted by 3GGG View Post
I will be building round plywood horns, made of lots of rings of plywood turned up on a diy lathe.
Hi Gregg,

The Height, Width and Width Flare parameters are not applicable to round horns. Simply set the 'Increment' value equal to the thickness of the plywood, and then use the exported length and radius results to construct the horn.

You have specified S1 = 20.30 and S2 = 6000.00 for your 120 hertz tractrix horn, giving a mouth Fta of 73.31 degrees.

Increasing S2 to 6539.49 would give a (fully formed) mouth Fta of 90 degrees.

Also, have you considered the possibility of perhaps using a Le Cléac'h flare, rather than a tractrix flare, for your 120 hertz horn?

Kind regards,

David
__________________
www.hornresp.net
  Reply With Quote
Old 19th March 2011, 11:04 AM   #1758
3GGG is offline 3GGG  Australia
diyAudio Member
 
Join Date: Mar 2010
Hi David

I was initially going to use the LeCleac'h flare, it was suggested by another forum member to look at the Tractrix flare. I see the LeCleach flare is alot shorter and rounder.
What is your opinion on each?
  Reply With Quote
Old 19th March 2011, 11:14 AM   #1759
diyAudio Member
 
Join Date: May 2007
A full Fta=180 LeCl will be close to 150cm dia, a FtA=90 in the ballpark of 115cm!

Compared to ca 85cm for Tractrix there could be a space-problem.
  Reply With Quote
Old 20th March 2011, 04:28 AM   #1760
3GGG is offline 3GGG  Australia
diyAudio Member
 
Join Date: Mar 2010
"The Con, Exp or Uni 'Width Flare' option specifies how the width increases along the length of the horn segment - this then also influences how the height increases. The Uni option causes the horn segment to flare uniformly in both the width and height directions. This option is most likely the one that you will want to use, I expect."

Ok David, I am getting a feel of this now. I have calculated my Horn for my Chosen Tractrix flare. Can you please expand on the above quote.
I am strill unsure what to choose for my round horns on the con, exp or uni drop down.
I will probably plot the dimensions straight on to a piece of thin MDF which can be used as a turning template.

Thanks again.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hornresp Class FlipC Subwoofers 8 3rd November 2008 06:23 PM
Some questions about hornresp brsanko Full Range 4 18th October 2008 09:36 PM
Hornresp help / JX150 316a Multi-Way 0 11th February 2004 03:56 PM


New To Site? Need Help?

All times are GMT. The time now is 12:47 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2