Talk:Thiele/Small parameters

Vas
The concept that a driver's Vas is related to the force created by compressing the volume Vas to one cubic meter is flawed. This is most clearly demonstrated by imagining that if a driver had a Vas of one cubic meter, it would then exert no force. Stiffness is force/distance and compliance is distance/force - neither of these has units of pure force as implied by stating: "...the volume of air when compressed to one cubic meter exerts a force equal to the driver's compliance". Ron E 00:58, 28 December 2005 (UTC)

Meter v/s metre.
I have noticed that unit for distances is specified/changed from "metre" to "meter". I have reverted it back to "metre". The correct nomenclature is "metre". See the article metre and its talk page as to why "metre" is the correct usage. In short, apart from US, almost every country where English is spoken has accepted "metre" as the standard nomenclature for measures of distance and "meter" as the standard convention to mean a measuring instrument. Please do not break this convention. Same for "liter". The correct word is "litre ". I have reverted this too. Rohitbd 08:34, 2 May 2006 (UTC)

cubic metre or cubic millimetre?
I am new to speaker parameters and just now learning, so if I am incorrect please understand that I am new to this and so my math maybe incorrect.

In the previous article regarding thiele/small parameters it is stated :

"Vas in the volume of air in cubic metres" Then a sentence later it is stated "to get the Vas in letres multiply by 1000, in the formula below" this would seem to imply that a cubic metre is equal to 1/1000 litre." Is that correct? I think a cubic centimeter is equal to a millilitre, but not a cubic metre. Or is the statement "Vas = to volume of air in cubic meters" not refering to the formula right below it? anyways somewhere something is wrong. 1 cubic metre is equal to 1,000 litres but are you supposed to multiply or divide? Anyway I might have the logic turned about in my head. Also I didn't want to change the main page...for fear of being incorrect and forever banned, so I thought it best to leave my post here. This is the first time to post in this "forum" so if my post is not supposed to be in this area please pardon that as well. I really like this site there is so much crap information on the internet it's nice to have a free reference source without hours of hunting down yahoo pages.L8R.....
 * Rest assured, there is nothing incorrect about the posted equations, I've been using them in this form for more than a decade. The volume units used in the equations is cubic meters. Since there are 1000 liters in a cubic meter, you need to multiply by 1000 to convert from cubic meters to liters.  Now if you wanted to use published specs (usually quoted in liters) in the equations provided, you would divide the Vas(liters) by 1000 to get Vas in cubic meters.  Units can be challenging even for engineers, it may help to work through a few examples using published specs to get a handle on things.  Drivers from Peerless, Vifa, Scan Speak and SEAS tend to have very complete parameter sets that make sense using these equations.  Some manufacturers, especially car audio companies, publish specs that are incomplete or inconsistent and will give problems when working through the equations.--Ron E 00:54, 1 June 2006 (UTC)

Cms and Rms missing in the Qualitative Descriptions section
It's a fine article, but I'd like to see Cms and Rms described in the Qualitative Descriptions section, too. I'm not qualified so I request that someone who is does it.Rygel 14:35, 19 December 2006 (UTC)
 * Brief descriptions added--Ron E 23:38, 11 February 2007 (UTC)

Added History and References sections
I added these sections to help show that there were a lot more people besides Thiele and Small working on Enclosure Design. Thiele, notably, stood heavily on the shoulders of Novak. There are some notable absences: Harry Olson, among others, because I do not currently have access to references other than those listed. The History section is largely from memory and could use some expanding, I hope there are not any gross factual errors.--Ron E 02:11, 12 February 2007 (UTC)


 * Ron, I appreciate your additions because I am working to compile historical and biographical information related to the history and current development of loudspeakers. Ancjr 09:26, 19 February 2007 (UTC)

This wiki is being discussed here: http://www.htguide.com/forum/showthread.php4?p=388478#post388478 —Preceding unsigned comment added by 86.90.75.149 (talk) 18:46, 6 March 2008 (UTC)

Name Change
Should the name of this article be changed? Say to Thiele and Small Parameters? 68.18.183.141 18:16, 17 June 2007 (UTC)
 * The idea that these parameters should be called Thiele/Small, or T/S, almost always with the "/", is deeply ingrained in the audio community. On the other hand, the "/" normally indicates directory structure in internet URL's.  Thus I have been conflicted since I first came across this article in its early stages.  I am inclined to leave it as is, because there are many webpages which link to the current URL.--Ron E 15:35, 24 June 2007 (UTC)

Resonance frequency
"Resonant frequency" is commonly used online, in texts and in conversation. I don't understand the page-wide change to "resonance frequency." Please explain. Binksternet 02:04, 31 August 2007 (UTC)


 * See the Resonance article; "resonant" doesn't describe the frequency, it describes the system. A frequency cannot be "resonant" itself, it is the frequency of resonance for a resonant system. Jbusenitz 13:08, 1 September 2007 (UTC)


 * Thanks for the explanation! I'll have to stew on it a bit. I'm this || close to 'getting' it. Perhaps it's related to folks using the phrase "resonant frequency" as a shortcut to "frequency at which the system is resonant"... :P Binksternet 22:19, 1 September 2007 (UTC)


 * I think you're probably right about the shortcut; it is a common one. The external link in Resonance (http://users.ece.gatech.edu/~mleach/misc/resonance.html) says it more eloquently than I can. I used to work with Dr. Small; he called me on it once and explained why. Jbusenitz 01:47, 2 September 2007 (UTC)

Opening for laypeople
Can we make the intro a little easier for the layperson to understand? I'll whip up something and post it here. I made this article so I could point my non-techie friend to a spot that described what Thiele/Small is, it's kind of confusing from that perspective. Jbmcb (talk) 17:23, 6 June 2008 (UTC)
 * Added a very brief explanation of what the parameters are for and where they come from.--Ron E (talk) 03:32, 11 June 2008 (UTC)

Description of Sd is obviously wrong
"Measured in square metres (m²). ... Generally accepted as the cone body diameter plus one third to one half the width of the annulus (surround)." — Preceding unsigned comment added by 69.181.66.220 (talk) 18:42, 11 September 2016 (UTC)

Thiele's contributions
If you read the editor's note (by J.R. Ashley) in the 1971 JAES reprint of Thiele's work, it is clear that although Ashley was impressed by the Table of "alignments" he did think that Thiele's work had much more merits than is stated in the "History" section here (i.e. "leaning heavily on Novak's work, A. N. Thiele described a series of sealed and vented box "alignments" (i.e., enclosure designs based on electrical filter theory with well-characterized behavior, including frequency response, power handling, cone excursion, etc.)"). Both Beranek's and Novak's works are mentioned in the editor's note, but still Ashley stated: "In his classic discourse Thiele observes that the topology of the equivalent circuit (Fig. 1) is simply that of a high-pass filter. If sufficient simplifications can be justified Thile reasons that the methods of modern network synthesis should be applicable to loudspeakers. This is a profound observation because it means that once the system transfer function is chosen, a logical sequence can be followed to specify driver and baffle parameters." And so, the importance of the work was possibly higher than just merely providing "a series of sealed and vented box 'alignments'", as is stated here. Therefore, the opinion expressed in the "History" section should have at least one reference. — Preceding unsigned comment added by 194.218.146.226 (talk) 12:56, 26 June 2018 (UTC)

Using T/S parameters to predict frequency response
As the purpose of knowing T/S parameters is often to predict frequency response (also, within an environment such as an enclosure with a certain air pressure and temperature), how can this be done? What are the relevant mathematics - not just commercial software which is available to assist with this. — Preceding unsigned comment added by Rocifier (talk • contribs) 22:42, 3 January 2022 (UTC)


 * The relevant equations are in the article. Practical applications can be found on the internet, including free downloadable Excel worksheets and basic speaker design applications, as well as the commercial software. Jbmcb (talk) 05:03, 10 February 2022 (UTC)