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 1st November 2011, 05:34 AM   #2371
diyAudio Member
 
Join Date: Jun 2007
Hi Zero D,

Quote:
Originally Posted by Zero D View Post
Cms is shown as for eg = 4.00E-04 What do they mean, & why can't we enter in m/N ?
Cms is given in units of metres per newton. Because the value is small, it is expressed in engineering notation (similar to scientific notation). A value of 4.00E-04 is the same as 4.00 * 10 ^ -4 or 4.00 / 10000 or 0.0004 m/N. Try entering 0.0004 into the Cms input box and see what happens.

Quote:
Originally Posted by Zero D View Post
Rms & Le arn't always quoted in driver TSP's, but i'm presuming these are auto calculated by HR ?
Just to clarify - Rms and Le are not Thiele-Small parameters, they are conventional electro-mechanical parameters. The values are not auto-calculated by Hornresp. If Le is not given in the driver's specifications, then set the value to 1.00 millihenry. It will be close enough for the purposes of the simulation. If Rms is not given, it can be derived using the Calculate Parameter tool.

Quote:
Originally Posted by Zero D View Post
I don't see anywhere to enter Xmax, so how is DD arrived at ?
From the SPL Response window, select the Maximum SPL tool and then enter the desired Pmax and Xmax values.

Quote:
Originally Posted by Zero D View Post
Also when clicking on some Data Entry Boxes i get popups for entering Vas & fs etc, & asking if other parameters are correct. I think it would be clearer/easier, for us to be able to have extra DEB's to enter these directly.
Sorry, it's not going to happen :-).

Quote:
Originally Posted by Zero D View Post
I've manged to modify your nice PDF, & highlighted in Yellow the text that was highlighted in Green in HR's Help File.
The secondary comments displayed in green in the Help file are shown in italics when printed out in hard copy form - as for the PDF file.

Kind regards,

David
__________________
www.hornresp.net

Last edited by David McBean; 1st November 2011 at 05:37 AM.
  Reply With Quote
Old 1st November 2011, 11:47 AM   #2372
diyAudio Member
 
Join Date: Jun 2007
Default Correction

Quote:
Originally Posted by David McBean View Post
Because the value is small, it is expressed in engineering notation (similar to scientific notation).
Just for the record - I should have said:

"Because the value is small, it is expressed in scientific notation (similar to engineering notation)."

0.0004 expressed in scientific notation is 4.00E-04
0.0004 expressed in engineering notation is 400.00E-06

Kind regards,

David
__________________
www.hornresp.net
  Reply With Quote
Old 1st November 2011, 12:15 PM   #2373
sannax is offline sannax  Norway
diyAudio Member
 
Join Date: Nov 2008
Can anyone point me to how to calculate a horn using a compression driver, and how to eventually calculate the throat angle of the horn (using Rta?)? My apologies if it has been discussed earlier in the thread.
Thanks!
  Reply With Quote
Old 1st November 2011, 12:44 PM   #2374
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
Quote:
Originally Posted by sannax View Post
Can anyone point me to how to calculate a horn using a compression driver, and how to eventually calculate the throat angle of the horn (using Rta?)? My apologies if it has been discussed earlier in the thread.
Thanks!
It's not really possible, since there aren't T/S parameters for the drivers.
  Reply With Quote
Old 1st November 2011, 01:11 PM   #2375
sannax is offline sannax  Norway
diyAudio Member
 
Join Date: Nov 2008
Quote:
Originally Posted by dirkwright View Post
It's not really possible, since there aren't T/S parameters for the drivers.
Ok, so what to do? How are people then able to calculate entry angel?
  Reply With Quote
Old 1st November 2011, 02:18 PM   #2376
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
Quote:
Originally Posted by sannax View Post
Ok, so what to do? How are people then able to calculate entry angel?
Well, don't use Hornresp generally for that. At least I haven't seen it.

I think most people who use compression drivers just follow the manufacturer's or their own ideas on which horn to use with it. Obviously, a 2" compression driver needs a horn with a 2" round throat, and the lower cutoff is given by the manufacturer, so you've got the basics for a horn right there. You can basically choose the shape and dispersion angles as you feel you need. Some folks put a waveguide on them, but that requires experimentation I think.

For example, if you've got the hots for the B&C DCM50, which is a 2" midrange compression driver, then I'd just follow the manufacturer's guidelines for using it. They say that it's good down to 400Hz, but the curve they show looks better at 500Hz, so that's the horn you need. Whether it's a tractrix, exponential, or whatever, is up to you. Making a passive crossover for compression drivers is even more hairy....
  Reply With Quote
Old 1st November 2011, 03:08 PM   #2377
sannax is offline sannax  Norway
diyAudio Member
 
Join Date: Nov 2008
Well, my plan is to make a LeCleach horn for a JBL 2" driver. I am certain that I have read about someone talking about the throat angle, have to search my computer. I am almost certain that Autotech makes horns on order with the right angle. I will ask in the Jmmlc thread.
Thanks!
  Reply With Quote
Old 1st November 2011, 04:05 PM   #2378
diyAudio Member
 
Join Date: Nov 2003
Location: California
Compression drivers have mechanical parameters just like any transducer. That means you can calculate T/S parameters for them if you want. However these parameters are not typically published. For some of the new JBL drivers, you can get a lot of the parameters from the data sheets published on the Audio Heritage website.
  Reply With Quote
Old 1st November 2011, 05:44 PM   #2379
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Is the throat exit angle of a compression driver stated in the manufacturer's datasheet?
__________________
regards Andrew T.
  Reply With Quote
Old 1st November 2011, 05:56 PM   #2380
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
Quote:
Originally Posted by John Sheerin View Post
Compression drivers have mechanical parameters just like any transducer. That means you can calculate T/S parameters for them if you want. However these parameters are not typically published. For some of the new JBL drivers, you can get a lot of the parameters from the data sheets published on the Audio Heritage website.
OK, here are the specs for the B&C DE10 1" compression driver. Is it possible to calculate T/S parameters from this data? I'm sorry I'm not expert enough to know how myself.
Attached Images
File Type: jpg B&C DE10 specs.JPG (37.9 KB, 139 views)
  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 10:46 AM.


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