Do lighter cones of a given size dampen and settle quicker? - 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 11th July 2012, 08:57 AM   #1
diyAudio Member
 
Join Date: Jan 2011
Location: Tennessee
Default Do lighter cones of a given size dampen and settle quicker?

Do lighter cones of a given size settle quicker? As the acoustical impedence goes up with frequency is their an optimum frequency for a given cone size and weight at which it is best self dampened by the air? Is there a formula for this?
A cone that settles quicker means less distortion probably as it nears its Xmax relative to other same sized cones that "ring" a little before the next excursion correct? Thanks in advance.
  Reply With Quote
Old 11th July 2012, 01:16 PM   #2
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by asberrys View Post
Do lighter cones of a given size settle quicker? As the acoustical impedence goes up with frequency is their an optimum frequency for a given cone size and weight at which it is best self dampened by the air? Is there a formula for this?
A cone that settles quicker means less distortion probably as it nears its Xmax relative to other same sized cones that "ring" a little before the next excursion correct? Thanks in advance.
A lighter cone requires less Bl (magnetic strength) to dampen it's movement than a heavier cone.
FS, the resonant frequency of the cone is dependent on cone weight, suspension compliance and Bl.
There is no one "optimum frequency", speakers are designed to cover a range of frequencies.
A lighter cone generally has more distortion when driven near Xmax than a heavier, stiffer cone.
  Reply With Quote
Old 11th July 2012, 01:41 PM   #3
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
The major source of distortion, especially at higher frequencies, is not cone 'overshoot' or something like that. It is cone breakup; the cone no longer acts as a homogeneous piston but starts to flex and have all kinds of local partial vibrations. So a stiffer cone that maintains pistonic behaviour has, generally speaking, less distortion.

jan didden
__________________
If you don't change your beliefs, your life will be like this forever. Is that good news? - W. S. Maugham
Check out Linear Audio!
  Reply With Quote
Old 11th July 2012, 04:50 PM   #4
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Given the complex interactions of the parts of a driver, the answer is: "ot depends on everything else". Motor, material, suspension, VC, shape, glues used...

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
Old 11th July 2012, 06:53 PM   #5
diyAudio Member
 
Join Date: Jan 2011
Location: Tennessee
Okay well thanks for the answerers. Let me further specify that the lighter cone is perfectly pistonic throughout its range. If another heavier cone speaker with the same resonant frequency is also perfectly pistonic in the same range what are the advantages of the lighter cone? it is more efficient? will it dampen and settle better? Yeah I know the lighter cone will require a smaller magnet and Bl product to have the same resonant frequency as the heavier cone. thanks.
  Reply With Quote
Old 11th July 2012, 07:39 PM   #6
diyAudio Member
 
Join Date: Nov 2003
Location: flyover country
My feeling is that a speaker with overall higher conversion efficiency (which goes with light cones for direct radiators) tends to have slightly less leftover energy to convert to high Q resonances, and the energy that is converted to unintended resonances tends to be lower in level relative to the intentional output.

An example might be two drivers of the same size with similar magnetic assemblies but one with a light cone and suspension having high conversion efficiency and one with a heavy cone and suspension with a low to moderate conversion efficiency might excite similar amounts of *mechanically* (as opposed to acoustically) coupled resonances throughout the enclosure, but the high conversion efficiency driver would have that much higher a direct output than the other which would mask those resonances more effectively. Plus, very high conversion efficiency direct radiators (assuming they have smooth responses) can translate 5-10% of their electrical energy into sound which would not tend to support resonances in the driver itself with Q's much higher than 3 -5 within their passband at least, so less in the way of droning type resonances would be expected from that mechanism.

Last edited by thoriated; 11th July 2012 at 07:56 PM.
  Reply With Quote
Old 11th July 2012, 08:00 PM   #7
diyAudio Member
 
mattlong8's Avatar
 
Join Date: May 2011
Location: San Francisco, California
momentum = mass x velocity*.

The more mass a moving body has, the more difficult it is to slow down *in it's direction of travel.
That being said, the real answer is much more complex as it varies with material, cabinet design and the driving signal.
[edit] As stated rather well above =).


-Matt Long
SF, CA

Last edited by mattlong8; 11th July 2012 at 08:05 PM.
  Reply With Quote
Old 11th July 2012, 08:19 PM   #8
diyAudio Member
 
Inductor's Avatar
 
Join Date: Feb 2006
Location: Cascais
OP. You probably will look at a mix of the two. You don't want the reflected sound waves from the inside of the cabinet at certain (mid-high) frequencies (in a very light cone).
__________________
NEXT-proaudio Portugal
  Reply With Quote
Old 11th July 2012, 08:58 PM   #9
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Quote:
Originally Posted by asberrys View Post
Yeah I know the lighter cone will require a smaller magnet and Bl product
to have the same resonant frequency as the heavier cone. thanks.
Hi,

Nope. It must have a higher Vas, less suspension stiffness for the same Fs.

It would need less magnet and BL for the same Qts at Fs. It would be more
efficient but as Vas has gone up need a bigger box for the same bass extension.

Cone mass is very much to due with the bass extension vs. efficiency
vs. box size tradeoffs for the driver, infinitely stiff or not doesn't matter.

rgds, sreten.
__________________
There is nothing so practical as a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow
  Reply With Quote
Old 11th July 2012, 11:03 PM   #10
Ron E is offline Ron E  United States
diyAudio Member
 
Ron E's Avatar
 
Join Date: Jun 2002
Location: USA, MN
Quote:
Originally Posted by asberrys View Post
Yeah I know the lighter cone will require a smaller magnet and Bl product to have the same resonant frequency as the heavier cone. thanks.
That's interesting, because Magnet size and Bl have nothing to do with resonant frequency.
__________________
Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan
Armaments, universal debt, and planned obsolescence--those are the three pillars of Western prosperity. Aldous Huxley
  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
Dampen transformer endbells? pjanda1 Tubes / Valves 13 22nd January 2013 08:25 AM
Is it possible to dampen a partially microphonic 12ax7? DrStrangelove Tubes / Valves 8 5th May 2011 12:19 AM
Dampen metal cone resonance: How much is enough? gary f Multi-Way 33 14th February 2009 04:53 PM
Question On Ports And Cones Cancellation and Relative Size kelticwizard Multi-Way 0 29th October 2007 11:12 PM
Help me settle something Lusso5 Solid State 5 24th October 2003 11:53 PM


New To Site? Need Help?

All times are GMT. The time now is 10:10 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