Woofer braces - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 8 Old 05-17-2012, 12:22 PM - Thread Starter
Member
 
pjoseph24's Avatar
 
Join Date: Jan 2012
Posts: 36
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I came across this the other day and was curious about the "woofer braces"
First time i have ever seen them was wondering of the benefits if any
http://www.subwoofer-building.com/
pjoseph24 is offline  
Sponsored Links
Advertisement
 
post #2 of 8 Old 05-17-2012, 01:42 PM
Say No to Auto EQ
 
beastaudio's Avatar
 
Join Date: Dec 2010
Location: Western NC
Posts: 8,067
Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 871 Post(s)
Liked: 976
Youll never see me siliconing my driver onto some braces inside the box. In certain cases I have seen people with SUPER heavy drivers supporting the drivers under the magnets, but other than that, the benefits are minimal if any at all.

(European models do not accept banana plugs.)

 

"If you done it, it ain't bragging." ~ Walt Whitman

 

AE TD12x SEOS12 Build

Beast's DIY Master Measurement Thread

DIY Emminence Coaxial Surround Thread

beastaudio is offline  
post #3 of 8 Old 05-17-2012, 01:47 PM
AVS Special Member
 
Jay1's Avatar
 
Join Date: Aug 2002
Location: AZ
Posts: 3,982
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 102
Thick gasket foam might be a smarter choice if you ever want to take the woofer out. I cant see much benefit if the driver is properly tightened down.
Jay1 is offline  
post #4 of 8 Old 05-17-2012, 02:09 PM
Say No to Auto EQ
 
beastaudio's Avatar
 
Join Date: Dec 2010
Location: Western NC
Posts: 8,067
Mentioned: 38 Post(s)
Tagged: 0 Thread(s)
Quoted: 871 Post(s)
Liked: 976
Quote:
Originally Posted by Jay1 View Post

Thick gasket foam might be a smarter choice if you ever want to take the woofer out. I cant see much benefit if the driver is properly tightened down.

yup, im holding an 85 pound driver on with just the 1 1/4" wood screws. That's 10.625 pounds of load per screw. I think they can handle that. Braces behind the sub touching the driver? where does that guy think it's going to go? fall into the box? hehe

(European models do not accept banana plugs.)

 

"If you done it, it ain't bragging." ~ Walt Whitman

 

AE TD12x SEOS12 Build

Beast's DIY Master Measurement Thread

DIY Emminence Coaxial Surround Thread

beastaudio is offline  
post #5 of 8 Old 05-17-2012, 03:03 PM
Senior Member
 
ovrrdrive's Avatar
 
Join Date: Feb 2008
Posts: 227
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Quote:
Originally Posted by beastaudio View Post

Youll never see me siliconing my driver onto some braces inside the box. In certain cases I have seen people with SUPER heavy drivers supporting the drivers under the magnets, but other than that, the benefits are minimal if any at all.


It's actually the secret of the box. The guy that told him to do that is now a salesman. Didn't you read the story?

(lol)

I bet the guy is a salesman alright... I wonder if he can also sell a ketchup Popsicle to a woman in white gloves.
ovrrdrive is offline  
post #6 of 8 Old 05-17-2012, 06:23 PM
AVS Special Member
 
Drew Eckhardt's Avatar
 
Join Date: May 2001
Location: Sunnyvale, CA USA
Posts: 2,674
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Quote:
Originally Posted by pjoseph24 View Post

I came across this the other day and was curious about the "woofer braces"
First time i have ever seen them was wondering of the benefits if any
http://www.subwoofer-building.com/

http://www.linkwitzlab.com/frontiers_2.htm#N
http://www.linkwitzlab.com/orion-rev1.htm

To quote Siegfried Linkwitz:

Quote:


There are two potential problems with the traditional way of mounting a driver by clamping it with screws to a baffle. One, the magnet/mass and basket/compliance can form together a very high Q resonant structure, where the magnet moves relative to the voice coil at a resonant frequency, which is typically in the 150 Hz to 450 Hz range. Two, structure borne vibration, which is generated by the considerable force that the accelerating cone of the driver exerts on the basket, is transmitted through the mounting scheme into the baffle. There it might be stored and re-radiated unevenly at different frequencies.

The resonance wouldn't be an issue with sub-woofers if it's out of the pass-band although I have no clue how the added magnet mass interacts with the larger basket structure.
Drew Eckhardt is offline  
post #7 of 8 Old 05-17-2012, 11:40 PM - Thread Starter
Member
 
pjoseph24's Avatar
 
Join Date: Jan 2012
Posts: 36
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Ahh i feel better now, i was thinking with all the reading i did before building my sub how could i have missed something like this!
pjoseph24 is offline  
post #8 of 8 Old 05-18-2012, 06:39 PM
AVS Special Member
 
BassThatHz's Avatar
 
Join Date: Apr 2008
Location: East side of NW Cascades
Posts: 3,199
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 350 Post(s)
Liked: 432
Isolating the mechanical resonances is "technically" ideal, but NOT AT ALL practical; and it is really only needed for frequencies above 120hz. Midranges and mid-woofer type stuff; in particular where the basket or box is very thin and thus prone to resonance.

(B&W uses this mounting method on all of their 800 series mids for example, although done much more professionally.)

For such a tiny/weak subwoofer that much bracing is a bit overkill (but it doesn't harm anything), and he was being way too generous with the anti-leak sealant... a properly glued joint will not leak air!!!

That type of support is not even needed for a heavy XXX-18 or LMS-18 magnet, the screws will hold it.

For subwoofers with high excursion that dig deep, the moving-mass begins to increase to a point where the enclosure may begin to shake and walk about. This can be solved by making it dual-opposed or mounting it perpendicular with respect to the floor or adding more box mass or by adding feet that counter it with increased surface "sticktion" (or spikes that dig in).
BassThatHz is offline  
Reply DIY Speakers and Subs

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

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