Talk:Damping factor: Difference between revisions

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== what would be an example of a large damping factor and a small one? ==

== Talk page layout ==

Thanks for any info. <!-- Template:Unsigned IP --><small class="autosigned">—&nbsp;Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/79.79.229.165|79.79.229.165]] ([[User talk:79.79.229.165#top|talk]]) 17:03, 23 November 2008 (UTC)</small>

=== Grahams statement ===

==Previous archive missing?==

Well readability is nothing to do with the amount of text, in my view... but I agree it's becoming very hard to follow the arguments here - there seems to be at least four different sections where things are still active. I'm not sure what the best thing to do is, but probably not archiving, for now. If you think this is bad, the situation over at [[Talk:Lift (force)]] is ten times worse! I guess the problem is that WP talk pages don't have some kind of threading arrangement. [[User:GRAHAMUK|Graham]] 05:38, 25 April 2006 (UTC)

This note was present at the top of this page, but the second link was a red link:

Earlier talk archived at:

=== LCs reply ===

*[[Talk:Damping factor/archive1]]

It may be a bit late to do anything here now. But what I tend to prefer is that each thread is kept separate under its own little hdg (whatever it may be like: 'Effect of NFB' say.) and people respond '''strictly''' at the '''end''' of that thread and do not interject (I know its hard). Also I feel it tends to make things easier to follow, in a long thread with multiple respondents, if people keed a constant indent under any heading. THis encourages people to start new hdgs often so that they are on minimum indent and 'Johnny come latelys' are tabbed half way across the page unless they start a new hdg.

*[[Talk:Damping factor/archive2]]

Ive had some success with this technique over on [[Talk:Ivor Catt]] where we have only had three respondents (but thats enough to police to see who's saying what). It does take discipline Im afraid!. I would like to know what you think of my scheme as I have been wondering about proposing it as a [[guideline]] for talk pages.--[[User:Light current|Light current]] 14:17, 25 April 2006 (UTC)

=== Refactoring ===

I believe that the talk pages should be refactored and new hdgs created to cover the material, then the relavant material moved under those hdgs as we go along. THe trouble is that some people object their posts being moved let alone edited.--[[User:Light current|Light current]] 15:20, 24 April 2006 (UTC)

== Arguing ==

I don't have much experience with loudspeakers so I haven't "participated" so far. Some comments on what's been said here so far:

* I think everyone here agrees that higher damping factor is better, right? No one's arguing the "negative feedback is bad" side of things?

* What you are arguing about is the point at which a higher damping factor makes no useful difference, right? This is because:

** The mechanical and electrical properties of the speaker mean it can't be perfectly damped. The voice coil has some resistance, the cone would still vibrate a little even if you could stop the voice coil perfectly, etc.

** Improvements beyond a certain point are inaudible to humans.

* Doing listening tests and arguing about personal experience is completely inappropriate. Wikipedia has a policy of [[Wikipedia:No original research|No original research]], which means the article should be based on [[Wikipedia:Verifiability|verifiable]] third-party measurements and theories; not your own. I'm sure there are people on both sides of the fence that you can quote, without interjecting your own opinions or research into the article.

* From reading these comments, from my perspective, Tvaughan1 seems to be making a better case (in the specific field of bass reproduction with heavy drivers, at least) than Light Current. And much more civilly at that; LC seems to often forget that [[WP:NOT#Wikipedia_is_not_a_publisher_of_original_thought|Wikipedia is not a discussion forum]] (or [[Wikipedia:What_Wikipedia_is_not#Wikipedia_is_not_a_battleground|battleground]]). — [[User:Omegatron|Omegatron]] 13:59, 24 April 2006 (UTC)

=== Response from LC ===

:OmegatronI would like to respond to your summary as follows:

:*I dont agree that higher damping factor is 'better' in all circumstances' as some my posts show. Also I make a clear distinction between 'damping' of a speaker and 'electrical damping'of a speaker

:*You are correct about the limit of detection of damping factor and the reasons Graham and I quote for it.

:*I dont believe '''I''' have been arguing about my personal exeprience.

:But now....

:Ahh Here we come to the thorny question of [[verifiability]]. There are references quoted which on inspection contain completely or partially wrong information IMO and can be shown to be wrong mathematically. Are these allowable or should they be disallowed if they can be proved wrong? TV! is basing his argument on a couple of refs from reputable manfs, but which clearly to me contain errors or stetching of the truth. In addition TV1 is refusing to accept any mathemeatical proof of my case that I offer and refers to his own personal experience.

:AS to the question of civility, I believe I am acting in a perfectly civil manner, I am merely trying to present a robust argument to someone who thinks he has all the answers based on his personal experience and a few dodgy refs.. In this way, as I have found out many times before, the truth will eventually emerge. And before you ask, No I dont think in this particular case, that a milder approach would work. I have many discussions with others on WP, and my robustness is in direct proportion to their strength (or obstinacy) of argument. Any way 'O' you should know my style by now.

:Finally, since you admit that you dont know much about loudspeakers, I think we can disregard your last comment about who is making the better case!--[[User:Light current|Light current]] 15:11, 24 April 2006 (UTC)

=== Reply to LC by Omegatron ===

''I dont agree that higher damping factor is 'better' in all circumstances' as some my posts show.''

: I don't see that in your comments. Can you summarize the instances in which it is harmful?

''There are references quoted which on inspection contain completely or partially wrong information IMO and can be shown to be wrong mathematically. Are these allowable or should they be disallowed if they can be proved wrong?''

: Can they be proved wrong by citing ''other'' references?

''Any way 'O' you should know my style by now.''

: I do indeed. I've seen you use the phrase "robust argument" many times as an excuse for mild incivility and personal attacks. Wikipedia is not a place to hold arguments at all. If you're just itching to get in fights, go find an audiophile discussion forum.

''Finally, since you admit that you dont know much about loudspeakers, I think we can disregard your last comment about who is making the better case!''

: Actually, my lack of pre-existing bias would make me a better judge of your arguments, don't you think? Are you sure you're not just disregarding me because I disagree with you?

: And maybe I'm mistaken, but I thought you just said you weren't making arguments about personal experience. — [[User:Omegatron|Omegatron]] 15:42, 24 April 2006 (UTC)

=== Admission of wrongdoing ===

At your request/comment I have removed my exhortations to TV1 to do testing. I hope this is satisfactory.--[[User:Light current|Light current]] 15:51, 24 April 2006 (UTC)

I have also removed what some may consider to be inflammatory statements.--[[User:Light current|Light current]] 21:04, 24 April 2006 (UTC)

: That's more than satisfactory. You probably could leave some of it. I really appreciate that you were willing to do that, though. — [[User:Omegatron|Omegatron]] 16:38, 24 April 2006 (UTC)

Thank you Omegatron!--[[User:Light current|Light current]] 21:58, 24 April 2006 (UTC)

=== Comment on talk pages ===

If WP is not allowing frank discussion of the page topics, then the talk pages may as well be closed down. However, I think that would be a retrograde step for many reasons. There may be a lot of hot air vented on these pages, but eventually, we do get some condensed nuggets of truth out of it. If we didnt discuss/argue as much, I think WP would be a lot poorer for it!--[[User:Light current|Light current]] 15:59, 24 April 2006 (UTC)

: Yes, we do need to discuss things, but we can get to the nuggets just fine without the hot air.

: I guess I don't really mean "argument". "Argument" can be used in several different ways, like "they got in an argument" (fight) or "he made a good argument" (part of a discussion). I'm really trying to keep this a comfortable discussion and prevent it from becoming a fight. In a fight, everyone says the same things over and over, goes on the defensive, and disregards what everyone else says. It leads nowhere. In a discussion, everyone has an open mind, tries to prove themselves wrong, only needs to state a particular argument once because everyone else genuinely considers it, etc. You seem to enjoy minor conflict more than discussions, and it's not good for our community atmosphere. That's what the [[Wikipedia:Civility|civility policies]] are meant for; "incivility is roughly defined as personally targeted behavior that causes an atmosphere of greater conflict and stress". — [[User:Omegatron|Omegatron]] 16:38, 24 April 2006 (UTC)

=== Thank you Omegatron ===

Thank you Omegatron for your cool, calming influence. It would be nice to think that 'we can get to the nuggets just fine without the hot air' tho Im not sure that can be achieved in every case -- it depends on the contestants. I do enjoy the discussions and I wasnt really getting angry with anyone and was not wanting to fight exactly but just defend my corner. I was just a bit indignant and over enthusiatsic, thats all. Yes I must learn to me more pateint with people. Its a fault I know I have - I just find it difficult to control. I do find it difficult to remain as cool as you do when its a subject close to my heart! And, as I say, I may wind people up without knowing it!

I would like to state that I bear no personal malice toward TV1 or anyone on WP. What I seek to challenge is peoples views and ideas where they conflict with mine. Thats natural, I think youll agree. Any way I do think that the engineering /science pages are a lot better behaved than some of the more controversial subjects where far worse arguments even wars have broken out.

Its amazing what tone you can pick up just from the phrasing people use tho' isnt it? Sometimes of course, it isnt meant in that way. But that's the limitation of text communication.

At least now we know that peoples own experiences are '''not''' valid on WP and we must find references to backup the statements we make. The only problem is when one side produces x number of references and the other an equal number saying the opposite thing. Then its a battle of numbers but I would hope some common sense might enter into it. As you know , you can prove black is white by using internet references!--[[User:Light current|Light current]] 21:04, 24 April 2006 (UTC)

: It's ok; you're not that bad. :-) [[Talk:John_Hutchison|Check out this guy.]] Hehehe

''Its amazing what tone you can pick up just from the phrasing people use tho' isnt it? Sometimes of course, it isnt meant in that way. But that's the limitation of text communication. ''

: Yep. That's why [[Wikipedia:Etiquette]] says: ''Keep in mind that raw text is ambiguous and often seems ruder than the same words coming from a person standing in front of you. Irony isn't always obvious - text comes without facial expressions, vocal inflection or body language. Be careful of the words you choose — what you intended might not be what others perceive, and what you read might not be what the author intended.'' — [[User:Omegatron|Omegatron]] 04:59, 25 April 2006 (UTC)

Maybe it should be mandatory to insist on a smiley (or other type) face at the end of each post? ;-)) --[[User:Light current|Light current]] 23:54, 25 April 2006 (UTC)

: They help a lot in conveying tone of voice. :-) — [[User:Omegatron|Omegatron]] 00:06, 26 April 2006 (UTC)

:: :-) Though I tend to overuse them a little. :-) — [[User:Omegatron|Omegatron]] 00:07, 26 April 2006 (UTC)

Youre quite right. We should all use them more often. I dont think you over use them. Its good to judge your mood! :-)--[[User:Light current|Light current]] 00:09, 26 April 2006 (UTC)

== Feedback from Crown Audio ==

I wrote to Crown Audio, to ask their opinion. Dave Engstrom, an Applications Support Engineer, was kind enough to reply. He gave me permission to quote him on his response to one of the statements in question ...

:''A large damping factor(greater than about 10) is no advantage to most listeners.''

:Theoretically true. However, if you test two amplifiers, one with high damping characteristic and one with low damping characteristic, a difference will still be perceptible. Output impedance is an electrical short circuit (so to speak). In actuality the NFb system of the channel involved generates an identical signal to the back EMF but inverted in polarity. They electrically cancel each other, very similar to CMR. The NFb circuitry has to track the speakers back EMF precisely or anomalies can appear. Thus the reason low NFb amplifiers cannot completely control the servo interfacing of the amplifier/speaker operation and interaction. In fact Crown amplifiers have always incorporated multiple NFb loops: one major and several minor nested loops.

:One other point to ponder: the "Damping Characteristic" of an amplifier does not change with the speaker wire resistance or load impedance variation. Whether 8 ohms or 4 ohms the Output impedance and level of NFb remain the same. High negative feedback provides for more than just damping factor: flat frequency response, low noise, low distortion.

:If I can be of any further assistance feel free to contact me.

:David Engstrom

:Crown Technical Support Department

I have heard from another expert, who told me he got a good laugh at the ''large damping factor is no advantage'' statement and the zero damping factor idea... but he has given up in frustration on trying to help out on Wikipedia. I know what he means.

[[User:Tvaughan1|Tvaughan1]] 19:40, 24 April 2006 (UTC)

=== Reaction by LC ===

Well TV1, full marks for initiative! :-)I wonder if we could use this (Crown) quote in the actual article? The other so called expert, however, (supplying no info other than a good laugh) Im not inclined to take as meaning anything at all unless he comes up with some hard facts or opinion.

When David says:

<blockquote>

''However, if you '''test''' two amplifiers, one with high damping characteristic and one with low damping characteristic, a difference will still be perceptible''

</blockquote>

We dont know what he means by the word ''test'' and ''perceptible'' do we? Is it an audible test? Neither does David say what he means by ''high'' and ''low'' damping factor. I think the detail of multilple fb loops is neither here nor there as far as DF is concerned. Also he doesnt say at what point low DF becomes audible.

Finally

When people give up in 'so called 'frustration', it either means:

*they are wrong but cant convince others of their view

*they are right but do not have the patience or words to explain thier position

*they are not really interested in writing a good encyclopedia.

Which category would you say you fit into?

--[[User:Light current|Light current]] 21:48, 24 April 2006 (UTC)

Did this other expert realise (or did you say) that it was zero '''electrical''' damping not zero total damping? I have never claimed that zero '''total''' damping is a good idea - far from it!--[[User:Light current|Light current]] 14:06, 25 April 2006 (UTC)

=== Reply by TV1 ===

''Can't convince others of their view''... well... some people are more open to new viewpoints than others.

Actually the feedback I received was more like "Wikipedia is too democratic"... to the extent that "2 idiots can outvote an expert, or 1 idiot can outlast an expert". I'm not calling you an idiot, you are obviously intelligent... but I think his point is valid (to me, at least). Wikipedia is very democratic, but for the process to work effectively contributors must recognize what they know and be willing to concede what they don't know for sure. Non-experts should be willing to defer to experts, and they should be willing to recognize expertise (personally, or in referenced articles). Contributors need to be open minded. They need to be cooperative. They need to refrain from personalizing the discussion. They need to respond to facts with more facts or theories with more theories. They need to stick to the topic.

You are as confident in your expertise as I am, so if it is just the 2 of us discussing the topic we get a stalemate. So we need 3rd party articles and opinions. Of course, if you just dismiss every reference, I have run into a brick wall. I'm only willing to run into a brick wall for so long. I'm motivated to help others... to help write a good article. I think my patience (and thick skin) is above average. No one has infinite patience.

Note that an amplifier with a high damping factor has more than just a low output impedance. It is designed with feedback circuits that force the signal voltage to the desired level... actively servo controlling the driver. So, this is active damping, not just passive damping. Dave Engstrom called it "damping characteristic". Dave has given permission to be quoted on the discussion page... I'll ask him if we can quote him in the article.

"Perceptible" shouldn't be a word that we are debating. It simply means that under a well designed test one or more people could reliably differentiate this audible effect. It means "can be perceived"... by anyone (not necessarily everyone). It doesn't mean that something is good or bad. It just means that it can be perceived. [[User:Tvaughan1|Tvaughan1]] 23:10, 24 April 2006 (UTC)

=== LC to TV1 ===

Im sure youre not admitting youre wrong are you? Read my post again--[[User:Light current|Light current]] 23:13, 24 April 2006 (UTC)

Also WP is not a democracy and 2 idiots cant 'outvote' an expert. But certainly one 'persistent idiot' (like me) can certainly outlast an im[[patient]] expert. What does that tell you? It tells me that the impatient 'expert' should be a bit more patient and explain to the 'persistent idiot' the error of his ways. Now which one of us is which?

--[[User:Light current|Light current]] 00:08, 25 April 2006 (UTC)

== The value of expert opinion ==

=== Omegatron to LC ===

''Also WP is not a democracy and 2 idiots cant 'outvote' an expert. ''

: They're not ''supposed to'', but they do often, actually. It's a big problem.

''It tells me that the impatient 'expert' should be a bit more patient and explain to the 'persistent idiot' the error of his ways.''

: No. It means that the other guy should stop being so persistent and both parties should work on citing references that say what they want instead of arguing.

: This is the reason why we have very few ''real'' experts on Wikipedia. People who really really know what they're talking about (PhDs) come here, think it's a cool idea, try it out, and get sick of it and leave. They're used to being respected or at least listened to, and there are way too many people here trying to turn everything into a fight or persistently editing about crackpot theories or their own obscure viewpoints. Or they have literally all day to modify the expert's work while he can only spend an hour or so per day fixing it, etc. etc. The policies are in place to try to prevent this kind of situation, but they aren't too effective because they rely on cooperation (or bannination) to keep things running smoothly. But we're waaaay too lenient on disruptive users, it's like we bend over backwards trying to tolerate people who aren't much better than vandals, in my opinion, and it drives away experts. </end Wikipedia rant> :-) — [[User:Omegatron|Omegatron]] 04:51, 25 April 2006 (UTC)

=== Reply by LC ===

The problem is actually that most people (inc me) behave like impatient experts when they know a little bit about a subject, when in fact very few of them are. Its only by trying to convince others that the error of your ways may become apparent. Its certainly shown me a few (minor) errors. Thats why argument on the talk pages is a good thing. But it does take time and patience. If cetain educated users do not have the time to explaian their arguments, then unfortunately, they are not the people WP wants as editors.

And I dont agree that all PhDs are infallible. Remember a PhD is a primarily a qualification in research methods. Ive worked alongside many, and outside their tiny sphere of knowledge (and sometimes inside), they're generally just as error prone as the rest of us but think they aren't (because they have a PhD). There is a case to be made for the average guys like us slogging it out and coming to a general consensus than just taking the word of some PhD (who could be wrong). And anyway what makes you think a PhD could write the perfect article in one hit?

So as I said before, it does require patience to be a long term contributor to WP and altho' I said I must be more patient, I must have some patience having been here almost 9 months without getting so frustrated that I want to leave. Im afraid that WP ''will'' have to rely on one million (or so) monkeys (plus a few gorillas) to write an encyclopedia. We must get used to it and keep pounding that keyboard.--[[User:Light current|Light current]] 12:13, 25 April 2006 (UTC).

BTW the [[gorilla]]s are not meant to be taken as the admins! (athough....)--[[User:Light current|Light current]] 12:57, 25 April 2006 (UTC)

== Change of heading ==

I notice you changed my heading to '''DF more critical for larger, more massive loudspeakers'''

Whilst changing other peoples postings is normally [[deprecate]]d, in this case I feel you may have highlighted something of importance. It may be worth persuing the idea that high DFs are more audible with very large (high mass) cones.

In fact I was thinking about this last night when considering your statement that you can tell the diff between a DF of 10 and 80 (say). But your system has very large sub woofers that are prone to cone breakup and I wondered whether that has anything to do with it. Also, you never said how you achieved the lower damping factor. Was it using a valve amp by any chance, compared to your normal transistor amp?--[[User:Light current|Light current]] 23:02, 24 April 2006 (UTC)

:I changed it to make it more meaningful, and less ridiculous. I can hear the lack of good damping when I use a cheaper amplifier with my speakers. The amplifier in question seems to match my Crown DC-300A II fairly closely on most specifications, except for damping factor. It's easy to hear the difference between tight bass and flabby bass. [[User:Tvaughan1|Tvaughan1]] 23:16, 24 April 2006 (UTC)

When you say cheaper amplifier, are you still using transistor amps?--[[User:Light current|Light current]] 00:05, 25 April 2006 (UTC)

:Yes. [[User:Tvaughan1|Tvaughan1]] 00:08, 25 April 2006 (UTC)

And this cheaper amp has a worse published DF?--[[User:Light current|Light current]] 00:24, 25 April 2006 (UTC)

:Yes [[User:Tvaughan1|Tvaughan1]] 00:39, 25 April 2006 (UTC)

In that case we must search for published material as references to back up your observations on large sub woofers!--[[User:Light current|Light current]] 00:42, 25 April 2006 (UTC)

== Interesting quotes ==

=== from JBL ===

<blockquote>[http://www.jbl.com/home/technology/glossary.aspx?language=ENG&country=US&region=USAact=glossary&term=D]

''In power amplifiers, it (damping factor) is a measure of the output impedance of the device. Expressed as a number arrived at by dividing the impedance into 8 ohms. For example, an amplifier with an output impedance of 0.04 ohms would have a damping factor of 8/.04=200. This, and higher numbers are common for solid state amps. Tube amplifiers have much higher output impedances and lower damping factors. '''In practice, the output impedance of the amplifier has almost no effect on loudspeaker damping,''' but it can have a significant effect on the frequency response of loudspeakers, most of which have frequency-dependent impedances. '''Within reason''', higher numbers are better.''</blockquote>

My bolding. --[[User:Light current|Light current]] 01:22, 25 April 2006 (UTC)

Would you like to comment on this TV1 since you have JBLs?--[[User:Light current|Light current]] 14:25, 25 April 2006 (UTC)

:It certainly is interesting. Perhaps they are operating under the assumption that the amplifier's damping factor will be sufficiently high. It is interesting that they point out the effect of damping factor on frequency response. If you take a look at some typical impedance curves for individual speakers (a single driver), you will see the large variation. A speaker that has a nominal impedance of 8 ohms may actually vary from 6 to 80 ohms over the range of frequencies that it is expected to reproduce. Keep in mind that JBL makes very high quality speakers (with relatively lightweight pistons and high quality surrounds), by and large, and usually sells them as a system in an enclosure (with good acoustic damping). JBL speakers have very powerful magnets and very high magnetic flux, and they are more efficiently driven and damped (electrically) than cheaper speakers. Still, I would defer to their Harmon Kardon brethren at Crown for advice on amplifier performance. [[User:Tvaughan1|Tvaughan1]] 18:24, 25 April 2006 (UTC)

What is sufficiently high in your opinion? And your speakers - did you mount them yourself or are they in a JBL cab? (I dont know if JBL do 2x18" cabs.) Are these your speakers by any chance? [http://www.goldsound.net/kit14.htm]--[[User:Light current|Light current]] 20:40, 25 April 2006 (UTC)

:They are in home-made cabs, designed to JBL specs... like the SR4718X. They are driven by a separate amplifier in a bi-amp setup (electronic crossover before the amps). Let's not get hung up on a particular pair of speakers... I have others, and the need for good damping isn't unique to one set of speakers. [[User:Tvaughan1|Tvaughan1]] 02:06, 26 April 2006 (UTC)

Im just trying to determine what may be special about your system that allows you to hear differences in DF! It does seem tho' that you are keen on having a very extended (subsonic) LF response :-|--[[User:Light current|Light current]] 02:16, 26 April 2006 (UTC)

===From esp===

<blockquote>

[http://sound.westhost.com/z-effects.htm]

''There was recently an article in Electronics World, where it was claimed that current drive helps to compensate for the resonant peak and voice coil inductance in a driver. While this is undoubtedly true (I've been doing it for many, many years), the designer must be very careful to ensure that the enclosure is particularly well damped, to avoid "overhang" when the signal is removed. This will typically manifest itself as poorly defined bass, particularly on transients, since the speaker must rely primarily on its own devices for damping.

Overall, this exercise has simply proven that which has already been proven by so many before me ...

* Voltage drive is the best choice in the vast majority of cases

* '''Moderate values of positive impedance can be useful - if the enclosure is particularly well damped'''

* Negative impedance is loathsome, and should be avoided''

</blockquote>

my bolding

--[[User:Light current|Light current]] 05:23, 26 April 2006 (UTC)

== THIELE - SMALL PARAMETERS: for JBL 2245H ==

*fs: 20 Hz

*Re: 5.8 ohms

*Qts: 0.27

*Qms: 2.2

*Qes: 0.31

*Vas: 820 L (29 ft3)

*Sd: 0.130 m2 (200 in2)

*Xmax: 9.5 mm (3/8 in)

*Vd: 1,230 cm3 (75 in3)

*Le: 1.4 mH

*no (Half space): 2.1%

*Pe (Max): 300 W Continuous Sine Wave

--[[User:Light current|Light current]] 23:17, 25 April 2006 (UTC)

== [[Marantz]] page mumbo jumbo ==

=== LCs statement ===

Refer to this [http://www.classic-audio.com/marantz/mdampingfactor.html]

<blockquote>

''The reason that a speaker might require more - or less - current given a particular applied voltage is that the '''impedance of the speaker system changes depending on what direction the speaker drivers are moving when the voltage is applied, how fast they are moving that way, and where they actually are in the first place.''' '''It helps to visualize that the intent of placing a voltage on a speaker system is to put the speaker cone(s) in (a) particular position(s).''' How difficult that is to do depends on the factors just mentioned (and others, some subtle.)''

</blockquote>

my bolding

Well, this is IMO just complete and utter horse droppings (with extra added BS). Where did this guy get these ideas? And who the hell is he anyway to be peddling this stuff? The speaker impedance does '''not''' depend on the direction or the amplitude of motion in a linear system. It may (will) depend on frequency.

Also [[voltage]] at speaker terminals does NOT determine the position of the cone. It is the voice coil [[current]] that does that. THe voltage comprises a portion due to I*Z and a portion due to the [[emf]] generated by the moving cone.(It is in fact I*Z + e) This is simple High School physics!

This sort of false info published on the net is most dangerous rubbish. Some people actually believe it and quote it as ultimate truth. :-(

--[[User:Light current|Light current]] 22:21, 25 April 2006 (UTC)

=== TV1s reaction ===

Light current... open your mind! It's not rubbish... it's just different way of describing the problem. Not the ideal description perhaps, but that's what we're trying to accomplish with this article, right?

A speaker is a driver. It has a motor. The piston has mass and inertia, and it acts against acoustic load and a mechanical spring (the suspension). The audio signal we are trying to accurately amplify and reproduce is represented as a varying voltage. What the author was trying to describe was the difficulty in getting the piston to move in response to the audio signal with precision. He is correct in describing that we want the position of the piston to be the mechanical equivalent (proportional) to the voltage of the electrical signal... just as the microphone diaghragm was moved by the acoustical signal (sound pressure variation), generating a voltage proportional to the movement.

Of course, Ohm's law tells us that V = I * R. A speaker doesn't have a fixed resistance, it has a voice coil with a reactive load, and this is measured as an impedance (Z). Nonetheless, if we assume the impedance is constant (it isn't... but this is a standard simplification), the current is proportional to the voltage. The EMF generated by the moving cone is the problem we are describing... the author was leaving it aside when he described what we wanted under ideal circumstances.

On to the part about more or less current being required. As you acknowledged, speakers have widely varying impedance. See [[Electrical characteristics of a dynamic loudspeaker]]. Why is this so? It is due to the natural resonant frequency of a speaker. In other words, the varying impedance is due to mechanical factors. The author of the Marantz article was trying to describe the need to electrically damp mechanical overshoot due to the inertia of the piston, or due to the mechanical resistance of the spring (suspension)... not averaged over time, but instantaneously. Of course, the only way to do this is to use feedback circuits to oppose the reverse EMF generated by the moving cone. This feedback will supply increased voltage (and current) as needed to compensate for varying speaker impedance and resonance... as the Crown engineer mentioned (higher damping characteristic gives improved frequency response). [[User:Tvaughan1|Tvaughan1]] 01:58, 26 April 2006 (UTC)

=== LCs restatement ===

I stand by my statement that this guy is talking thro his *****le. I reiterate my statement that:

<blockquote>

''[[voltage]] at speaker terminals does NOT determine the position of the cone. It is the voice coil [[current]] that does that. The voltage comprises a portion due to I*Z and a portion due to the [[emf]] generated by the moving cone.

''

</blockquote>

I invite anyone to try to prove me wrong (or right if you so desire). Comments from other educated editors are welcome. :-|--[[User:Light current|Light current]] 02:05, 26 April 2006 (UTC)

== Critical damping ==

I think Im right in saying that what is required from a low [[frequency]] speaker system is [[critical damping]]. That is, not under[[damping]] (where you get hangover) or over damping (where the cone just wont move fast enough in response to a step voltage input). Now it is my contention that a speaker is a [[mechanical]] system with a mechanical to [[electrical]] [[transformer]] (the voice coil) attached and this transformer is driven by an amplifier of usually very low output impedance.

=== Transformation analysis ===

Since the mechanical force on the coil, f_m is given by:

'''f_M=Bli'''

and the emf developed by the moving coil is

'''e= Bl dx/dt'''

It is therefore evident that:

'''Z_EM= (Bl)^2/Z_M'''

where Z_EM is the electrical impedance due to motion, and is termed the 'motional electrical impedance'. The mechanical to electrical transformation ratio for impedances is therefore (Bl)^2 and is determined solely by the voice coil/magnet assembly.

Now in analysing such a system, one may choose to convert the mechanical components ([[mass]], [[compliance]], acoustic [[resistive]] or [[reactive]] loading etc) into electrical [[component]]s or vice versa by referring the elements to one side or the other of the 'transformer'. It is usually easier to do the former and analyse the performance in the electrical ___domain. The mechanical/electrical transformer is of course an [[electric motor]]/[[generator]].

The transformation constant (Bl)^2 is a scalar and therefore does not change the phase angle of the impedance when transformed, only its magnitude. Therefore inductive components (masses) transform to inductances, and capacitive (compliances) transform to capacitors, whilst resistors (mechanical dampers) transform to resistors.

The ''total'' electrical impedance seen at the voice coil by the amplifier, Zen, is given by the sum of the [[damped]] electrical impedance and the [[motional]] electrical impedance ie:

'''Z_en =Z_e1 +Z_em'''

Now Z_en can be represented as a series combination of R,L and C. The L represents the transformed mass of the cone in the mechanical cct, and the C represents the total transformed compliance of the driver. The R represents the sum of the transformed motional resistance '''plus''' the electrical (DC) resistance of the voice coil.

=== Damping methods ===

It should be evident that damping of this (essentially second order) system can be accomplished either by [[mechanical]] means or by electrical means or by a combination of the two. There is however an inherent limitation in the 'electrical only' damping method. That is the finite [[resistance]] and inductance of the [[voice coil]]. This can only be reduced by the use of a 'negative' resistance in the amplifier and this is usually not employed for stability reasons (ie it tends to turn the system into an oscillator)

The complete electrical [[equivalent circuit]] of a [[loudspeaker]] in a [[cabinet]] is shown in the figure.

For the system to be critically damped, we can see that in the electrical equivalent circuit, R must be of a certain (critical value.

'''To be continued...''' Please do not interrupt this post >:-{

--[[User:Light current|Light current]] 17:02, 26 April 2006 (UTC)

----

: Yes. We do. Across the full frequency range of the speaker. But the article is about damping factor, so it needs to focus on how you design or evaluate an amplifier (which may have any speaker connected... cheap or well designed... in various configurations (alone, series, parallel), through wires with unknown length or resistance. [[User:Tvaughan1|Tvaughan1]] 22:38, 26 April 2006 (UTC)

OK then watch this space!--[[User:Light current|Light current]] 22:14, 27 April 2006 (UTC)

I'm changing to the archive template and archiving another chunk through 2007. — [[user:MaxEnt|MaxEnt]] 10:11, 7 April 2014 (UTC)

== Holy bejesus, cleanup? ==

:That's because the links are wrong. The first has a redirect, but they should correctly read:

I can't believe this page! Its like 5 times as long as the article. Does anyone think this talk page needs some cleaning/archiving or something? [[User:Fresheneesz|Fresheneesz]] 04:17, 19 May 2006 (UTC)

:*[[Talk:Damping factor/Archive 1]]

:*[[Talk:Damping factor/Archive 2]]

:[[Special:Contributions/86.174.152.128|86.174.152.128]] ([[User talk:86.174.152.128|talk]]) 12:02, 21 May 2017 (UTC)

== archiving is nonsense ==

Ive archived about 40k s worth but we're still in the middle of a heated discussion so I think the rest should stay for a while. Just having a cool off between rounds!--[[User:Light current|Light current]] 13:22, 19 May 2006 (UTC)

Sorry, but to archive SMALL Quantities of text

I consider that as nonsense.

The article is not as good, the contribution here usually help.

== audio only? ==

--[[User:AK45500|AK45500]] ([[User talk:AK45500|talk]]) 16:43, 11 June 2021 (UTC)

== Critical damping of loudspeakers ==

Is this page only applicable to audio amplifiers? Comming to a page on the damping factor, I would expect a more general treatment. For example, I was looking for the definition of the damping factor in terms of any general circuit. Does the definition of source impedance vs load impedance work in general, or just for audio amplifiers? [[User:Fresheneesz|Fresheneesz]] 00:22, 5 June 2006 (UTC)

I believe that critical damping of a loudseaker cone by electrical methods is, in almost all cases, impossible due to the non zero resistance of the voice coil. --Light current 10:30, 28 June 2006 (UTC)

: Just use a '''negative impedance''' at the amplifier.

:No, its not restricted to audio amps ATM! It should be a very general treatment.

: --[[User:AK45500|AK45500]] ([[User talk:AK45500|talk]]) 16:45, 11 June 2021 (UTC)

== Large Damping Factor is desirable for audio amplifiers ==

:We could put a note at the top of the page saying this page only applies to audio and redirecting others to [[damping]]?

I have a real problem with this statement... "A large damping factor is no advantage beyond a certain point, probably around 10." This is totally not true... and totally obvious to anyone who works in the professional audio field, as I do. A large damping factor (100 or greater, preferably 400 - 1000) is highly desirable, and mandatory for quality bass reproduction, given the way that loudspeakers work. Please read the referenced article from Crown Audio. Anyone who believes a large damping factor is no advantage is confusing the issue of feedback (and possible negative effects of feedback) with damping factor. Tvaughan1 22:33, 21 April 2006 (UTC)

: Sorry I consider this as ... . I do not think, that anyone in the professional audio field is not able to calculate the Brake-current.

:The definition 'source impedance vs load impedance' is specifically reserved for audio amps and is not the general defn of damping factor. Please see [[damping]] 8-)--[[User:Light current|Light current]] 00:30, 5 June 2006 (UTC)

: From damping factor 10 to 400 the current, that will slow down the cone, after the signal ceases will increase by 0.15 dB . It will decrease again if the coil increases by 100 Kelvin.

:But you are shure the whole audio comunity considers a 0.15 dB 'faster' acceleration or damping is important. You know, the damping 10 will increase BASS response a little tiny bit compared to 400 ! A lot of peaople consider that as desirable.

:Yes , high damping may (sometimes) be HIGHLY desirable. But then please use a Damping factor of -5 or -3 ( ¡ minus ! ). Look at Yamaha or old REVOX subwoofers. --[[User:AK45500|AK45500]] ([[User talk:AK45500|talk]]) 17:09, 11 June 2021 (UTC)

:: The results indicated that any damping factor over 10 is going to result in inaudible differences between that and a damping factor equal to infinity. However, it was also determined that the frequency-dependent variation in the response of the loudspeaker due to the output resistance of the amplifier is much more significant than the effects on system damping.

:: These two sentences contradict each other. Output resistance partially defines damping factor so you can't say "damping factor over 10 doesn't matter but <different way of saying damping factor> is much more significant"

:: Not sure if the bit in the paper is poorly written or assumes a great deal of context about what they're referring to, but the quote in the wikipedia article loses all that context. [[User:Xaxxon|XaXXon]] ([[User talk:Xaxxon|talk]]) 05:49, 27 January 2023 (UTC)