Enough bracing? - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

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 16th September 2003, 02:10 PM   #1
Vikash is offline Vikash  United Kingdom
diyAudio Moderator Emeritus
 
Vikash's Avatar
 
Join Date: May 2003
Location: UK
Default Enough bracing?

I'm building this at the moment but I'm not sure if I can get away with this little bracing (run out of mdf). And if I do only use one brace can someone confirm this is the optimal place to put it.
Attached Images
File Type: gif bracing.gif (10.5 KB, 1717 views)
  Reply With Quote
Old 16th September 2003, 02:16 PM   #2
rho is offline rho  Belgium
diyAudio Member
 
Join Date: Sep 2003
Location: Peer, Belgium
I would not put it exactly in the middle of the box. Put it at 3/5 or 4/7. This makes the reconance of the part in front of the brace different from the part behind the brace.
  Reply With Quote
Old 16th September 2003, 02:31 PM   #3
mcp is offline mcp  United States
diyAudio Member
 
Join Date: Jul 2002
Location: Vacation Land
And watch your ratios.
__________________
Michael Chua
  Reply With Quote
Old 16th September 2003, 02:33 PM   #4
diyAudio Member
 
Join Date: Jul 2003
Location: Newcastle, Australia
I would be inclined not to brace top to bottom, as these are the most rigid panels. The baffle will be the weakest, especially between the woofers. I would suggest a similar MDF arrangement to yours but front-to-back, one between the woofers (with cutout around the tweeter) and another one lower down. A brace can also be run between the lower crossbrace and the upper port to support this.

Cheers
  Reply With Quote
Old 16th September 2003, 03:13 PM   #5
Rarkov is offline Rarkov  England
diyAudio Member
 
Rarkov's Avatar
 
Join Date: Aug 2002
Location: North East, UK
Send a message via ICQ to Rarkov Send a message via Skype™ to Rarkov
Why not place it diagonally. I mean from bottom Left to Top right.

That would give you the best of both worlds.

Gaz
  Reply With Quote
Old 16th September 2003, 05:01 PM   #6
Vikash is offline Vikash  United Kingdom
diyAudio Moderator Emeritus
 
Vikash's Avatar
 
Join Date: May 2003
Location: UK
Just came across this thread:

Quote:
It has been shown that while just about any bracing helps to stiffen a box, the best way to brace is along the vertical dimension. That is, a box that is two feet high by a foot wide by a foot deep should be braced with two foot long braces running top to bottom on the inside. One foot long horizontal braces are not nearly as effective. This has been studied in an article in the Journal of The Audio Engineering Society. - Kelticwizard
I've read this before as well. Argh. Gonna have to do some reading now...

Ok, what about the holes in the brace? I was actually thinking about like 20 x 8cm dia. holes. How do I know when there's enough space for the cabinet to breathe through the brace without negative effects?
  Reply With Quote
Old 17th September 2003, 04:38 AM   #7
getafix is offline getafix  Philippines
diyAudio Member
 
getafix's Avatar
 
Join Date: Jun 2003
Location: somewhere in Mandaluyong
Quote:
Originally posted by Centauri
I would suggest a similar MDF arrangement to yours but front-to-back, one between the woofers (with cutout around the tweeter) and another one lower down. A brace can also be run between the lower crossbrace and the upper port to support this.
I tend to agree with this rather than putting the brace parallel to the long panels, which tends to flex more than short panels.
__________________
forever dreaming of a better set-up...
  Reply With Quote
Old 17th September 2003, 05:05 AM   #8
mcp is offline mcp  United States
diyAudio Member
 
Join Date: Jul 2002
Location: Vacation Land
You may want to check your internal ratios (WxHxD). Looks like you will have some nice standing waves with your present dimensions.
__________________
Michael Chua
  Reply With Quote
Old 17th September 2003, 05:49 AM   #9
navin is offline navin  India
diyAudio Member
 
navin's Avatar
 
Join Date: Jan 2002
Location: Mumbai (Bombay), India
Send a message via MSN to navin Send a message via Yahoo to navin
Quote:
Originally posted by Centauri
I would be inclined not to brace top to bottom, as these are the most rigid panels. .. I would suggest a similar MDF arrangement to yours but front-to-back
Cheers
i agree with this. front to back below woofer and behind tweeter should help most.
__________________
...still looking for the holy grail.
  Reply With Quote
Old 17th September 2003, 07:35 AM   #10
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
If there is only enuff material for a single brace then you have it right... do make sure that the brace divides the panel unevenly... a ratio with an irrational number is best.

The side panels are the largest and will resonate at lower frequencies than any other panel, so they are the most important to divide up.

If you can slant the brace so as to divide the side panels into non-rectangular shapes even better.

perhaps you can use some of the materials from the holes to brace the back of the woofs against the brace -- you could line up the "not hole" part of the brace to facilitate this -- if you can run the woofer braces all the way to the back (ie a 2nd bit from the brace to the back, even better.

Mounting the drivers push-push would be even better, then you can have active vibration cancellation.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  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
Bracing an enclosure preiter Subwoofers 5 17th July 2006 10:54 AM
Does A Box Like This Need Bracing? sdclc126 Subwoofers 10 12th May 2006 01:31 AM
how much bracing is enough gwgjr31 Subwoofers 1 5th May 2006 06:57 AM
do I need bracing for a 15L BR? RockysDad Full Range 12 11th August 2005 07:18 PM
enough bracing?? Chris8sirhC Multi-Way 3 31st January 2004 08:16 PM


New To Site? Need Help?

All times are GMT. The time now is 11:26 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