Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Comments on bass horn sim in horn response
Comments on bass horn sim in horn response
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 31st October 2005, 02:19 AM   #31
mike.e is offline mike.e  New Zealand
diyAudio Member
 
mike.e's Avatar
 
Join Date: Sep 2004
Location: NZ
Send a message via ICQ to mike.e Send a message via MSN to mike.e
Thats still a large horn slowmotion : Id consider one with half the mouth area,and correspondingly less path length.

The beta8 is probably quite cheap too!

Otherwise id go car audio 10"
  Reply With Quote
Old 31st October 2005, 08:14 AM   #32
paulspencer is offline paulspencer  Australia
diyAudio Member
 
paulspencer's Avatar
 
Join Date: Sep 2003
Location: Melbourne, Australia
The biggest problem I'm having is IMO "compression ratio!" The designs seem to call for a very small throat, ie 10% of SD, which is a compression ratio of 10 right? As far as I'm aware, this is too high! Make it closer to SD and the response is no longer flat!

How high can I go in compression ratio?

What are the problems if I go too high?
  Reply With Quote
Old 31st October 2005, 08:41 AM   #33
slowmotion is offline slowmotion  Norway
diyAudio Member
 
slowmotion's Avatar
 
Join Date: Nov 2002
Location: Norge
Hi

Quote:
Originally posted by mike.e
Thats still a large horn slowmotion : Id consider one with half the mouth area,and correspondingly less path length.
You'd get a smaller horn, but also more ripple.


Quote:
Originally posted by paulspencer
The biggest problem I'm having is IMO "compression ratio!" The designs seem to call for a very small throat, ie 10% of SD, which is a compression ratio of 10 right? As far as I'm aware, this is too high! Make it closer to SD and the response is no longer flat! :
Huh?
SD on the Beta 8 is 214 and the throat in the example is 100. That's not what I would call high compression ratio.

cheers
__________________
- Jan -
  Reply With Quote
Old 31st October 2005, 10:20 AM   #34
paulspencer is offline paulspencer  Australia
diyAudio Member
 
paulspencer's Avatar
 
Join Date: Sep 2003
Location: Melbourne, Australia
Jan, I was referring more to the results I get from the "Hypex designer" feature. I tend to find better simulated results also from a high compression ratio. I'm trying to find out what my limits are here ...

even the example you gave has a compresssion ratio greater than 2 which I thought was considered a safe limit, unless I got it wrong.
  Reply With Quote
Old 31st October 2005, 11:06 AM   #35
slowmotion is offline slowmotion  Norway
diyAudio Member
 
slowmotion's Avatar
 
Join Date: Nov 2002
Location: Norge
Hi

Paul, then I misunderstood

Re the "Hypex designer" feature, well,
better to start from scratch when designing horns, I think....


cheers
__________________
- Jan -
  Reply With Quote
Old 31st October 2005, 11:45 AM   #36
paulspencer is offline paulspencer  Australia
diyAudio Member
 
paulspencer's Avatar
 
Join Date: Sep 2003
Location: Melbourne, Australia
Jan, so how do you "start from scratch?" Do you have some rule of thumb guidelines to start out?
  Reply With Quote
Old 31st October 2005, 03:01 PM   #37
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Greets!

10:1?!!!!! Altec compression drivers are this high and look at the construction/horn size required to get a 500 Hz/2nd order Fc. Extrapolating to 40 Hz would require a motor hoist to put in position and turn a large personal fortune into a small one to make.

In the 'good ol' days', horn drivers/lens were initially designed as theoretically ideal full size exponential since sound pressure is exponential (1/f) and if it was acoustically long enough it generated a smooth response over the desired BW with a second order roll off at both ends once reactance annulled. If it was too long or there wasn't a suitable driver or it had too much gain and/or BW for the app, a 'slice' of it was used that best met the performance goals with the desired driver(s), ergo the early truncated designs from Altec, etc..

Anyway, in today's 'techo world' Leach's math will give you your answers. Remember, any driver can be optimally horn loaded over some BW at some efficiency, so the main question is, does its specs meet the needs of the desired performance goals? If not, use his math to find the ideal driver and if it doesn't exist in this reality, then find the closest to it and sim how much it compromises your goals, etc.. At least you won't have to actually cobble together/measure an old chicken coop full of proofs-of-concepts like I did to get yours.

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote
Old 31st October 2005, 04:57 PM   #38
slowmotion is offline slowmotion  Norway
diyAudio Member
 
slowmotion's Avatar
 
Join Date: Nov 2002
Location: Norge
Hi Paul, all

Here's a link to a webpage by John Sheerin:

http://ldsg.snippets.org/HORNS/design.html

The page has further links to Leach's page.

cheers
__________________
- Jan -
  Reply With Quote
Old 1st November 2005, 08:34 PM   #39
mike.e is offline mike.e  New Zealand
diyAudio Member
 
mike.e's Avatar
 
Join Date: Sep 2004
Location: NZ
Send a message via ICQ to mike.e Send a message via MSN to mike.e
Its interesting how the equations reccomend often,a high compression ratio which isnt normally practical.

Biggest basshorns
http://www.geocities.com/xobt/bassho...rns.htm:smash:
  Reply With Quote

Reply


Comments on bass horn sim in horn responseHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
More then one driver in Horn Response jamikl Subwoofers 2 4th February 2009 11:44 PM
Another big horn dream... comments and concerns? just a guy Subwoofers 50 22nd February 2008 10:16 PM
Front horn, HF response. jnb Multi-Way 6 22nd February 2008 02:50 PM
how to go from horn response to a folded bass horn design? paulspencer Subwoofers 8 4th November 2005 10:44 PM


New To Site? Need Help?

All times are GMT. The time now is 06:42 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki