Talk:Loudspeaker/Archive 1

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This is an archive of older "talk" from the Loudspeaker article up to and including April, 2006.

For the most recent discussion, see Talk:Loudspeaker.

Line versus point sources?

Would this be the place to have an entry for a line array and point source? or should those be entirely different articles?

You could put them here to begin with. If the article gets too big, someone will move them to their own articles later. --Heron 07:56, 9 Sep 2004 (UTC)

Split Enclosures section to Loudspeaker enclosure

I believe that it would be a good idea to split the article because although enclosures are part of a loudspeaker, they also are a componant of their own, and it diserves its own article. I have already setup a Subwoofer enclosure Loudspeaker enclosure article and linked about 10 articles there, and then redirected it to Loudspeaker for now. Please comment:

Well, IMHO all enclosures except the band-pass, PR, and dipole are used in non-subwoofer applications also. So if it is split, it would be better to include all enclosures in the article and name it "Loudspeaker enclosures" instead of "Subwoofer enclosure", indicating in the article the common application of each enclosure (i.e. general purpose/bookshelf/subwoofer/etc). Rohitbd 09:53, 10 March 2006 (UTC)
Ok, Thats a good idea, Loudspeaker enclosure would be a better name. So do you agree that it should be split if it goes to Loudspeak enclosure? Fosnez 10:28, 10 March 2006 (UTC)
Well apart from a small change to the name to "Loudspeaker enclosures", I have no issues. However, you may want to get a few more opinions before proceeding. Rohitbd 10:46, 10 March 2006 (UTC)
Indeed I will Fosnez 14:53, 10 March 2006 (UTC)

Speaker Casing Design

I am currently a media production student studying 3D design as part of my solid modelling module. I am trying to design a futuristic (25 year gap) speaker. Having hunted there appears to be little about the future design of speaker casing most searches have led to dead ends............... can anyone please offer a resultant target?

Hehe, I think in 25 year's time, loudspeakers won't resemble anything we know today and will most likely not require enclosures as we know them. Speculations on future LS design hint at excitation of air molecules without physical diaphrams, much like plasma modulators. Who knows, maybe when we get a grip on the invisible forces surrounding us, we can coax the air molecules to mirror the exact recorded perfomance without our current relatively crude actuators!
Model a small orb with a slight indentation on the top and call it "The Acoustic Exciter" ;)
Visor57 10:38, 9 December 2005 (UTC)

first picture

Not to nitpick, but the first photo is a single woofer driver, not an entire speaker.

Actually, it IS a loudspeaker; it simply has no enclosure.
Atlant 23:29, 20 Apr 2005 (UTC)

Actually, it is a loudspeaker driver of indeterminate frequency range. Could be woofer, mid-bass, or "full-range."

To be technically correct, a loudspeaker is a complete unit encompassing one or more drive units contained, together with any electronic components (active or passive), within a suitable enclosure.
The system functions as a whole.
Unfortunately the word loudspeaker is easily employed to describe the drive units themselves, and this should be corrected wherever possible.
Visor57 09:22, 9 December 2005 (UTC)
The major problem with this part of the article (picture AND caption) is that this is not a "loudspeaker driver", or at least it should not be referred to as such. This is a cheap, stamped frame, 25 cent piece of junk. It could be used in almost any type of speaker, including "full range with decorative assist". It's a bad example.
AMSTEREO 3:10pm, 16 Jan 2006 (EST)

what's with the enclosure sketches?

Is it just me, or do those two sketches in the enclosure section tend to come and go randomly on random days? today i can see the first one and not the second one, which is a new phenomenon. Gzuckier 03:18, 9 May 2005 (UTC)

LFE vs. bass management

I added a little note at the end of subwoofers re: the LFE channel on modern decoders since there is often confusion about its purpose. I'll edit the LFE page later to be more informative instead of blathering about it where its not relevant. MtB

Thanks for that improvement!
Don't forget to sign your notes on "talk" pages (I've done it for you). You can easily include your signature and a timestamp simply by ending your note with ~~~~ (four tildes); that will be replaced by a hyperlink to your Wiki username and the current timestamp.
Atlant 15:49, 20 May 2005 (UTC)

Charged flames

I removed this aside from the text, as it didn't help to explain how plasma speakers work.

(the electron, which carries the charge in an electrical current, is defined as a negative charge only because the repulsion of positively charged candle flames from a positively charged electrode and towards a negative charge was misunderstood as the flame being blown by a flow of charge carriers from one electrode, which was therefore labeled as positive, needlessly complicating the life of beginning engineering students).

It might belong somewhere in Wikipedia, if it's true. --Heron 18:35, 11 July 2005 (UTC)

series / parallel connections

This article should include a section on series vs parallel speaker connections. I am trying to figure out the difference, and how those connections are set up, and cannot seem to find a simple explanation.

Howzabout this as a start for your thinking:
Speakers can be connected in series, parallel, or series-parallel networks. When connected in series, their impedances are generally additive. When connected in parallel, their impedances are generally described by the formula
(as with parallel resistors). This change in impedance with either a series or parallel connection may affect the performance of the speakers, the amplifier, or both. When connected in series, there may not be sufficient voltage from the amplifier to drive the speakers to produce an adequate volume. When connected in parallel, the speakers may impose too great a current load on the amplifier, leading to the amp overheating or simply shutting down. Because of this, the use of speakers in series or parallel circuits must be carefully evaluated.
A common solution to this problem in large installations is the use of Constant Voltage Circuits. (And I think these are described elsewhere in the article.)
Atlant 16:40, 18 August 2005 (UTC)

Two terminals? Or more?

A recent edit to the article stated that "All speakers have two terminals...".

This is incorrect. Some multi-driver speakers allow for the possibility of bi-/tri-amplification by containing separate terminals for the tweeters, midranges, etc. Ordinarily, the multiple "hot" terminals are connected together by jumper wires, but these can be removed to allow separate operation of the separate drivers.

And then there were the off, multi-impedance speakers that contain multiple terminals that connect to multiple taps on the voice coil...

Atlant 14:00, 2 September 2005 (UTC)

In the industry, the terminals used to connect to a loudspeaker are referred to as binding posts, whereas the terminals are the connections of the drive units themselves (some may also have multiple terminals).
It is not uncommon for binding posts to be used as the terminals of expensive drive units.
For Bi-Amping, etc, Dual Binding Posts are required along with removable jumpers.
Binding posts typically facilitate the use of varied cable terminations such as bananna plugs, spade lugs and raw cable cores.
Visor57 09:36, 9 December 2005 (UTC)

Power Ratings / Capacity

Would someone mind expounding on the various loudspeaker power capacity ratings? What is peak power, program power and continuous power?


Jeb6kids 14:55, 13 September 2005 (UTC)

I think some of those terms are more "markieting speak" than a formally-defined measure. Only "continuous power" strikes me as having a firm definition.
But let's consider what will destroy a speaker:
  1. Too much RMS (heating) power. If you flow too much RMS power through the voice coil for too long a period, then the time-integral of the heating will melt the voice coil or cause its support structure to catch fire. So too much "continuous power" is bad for a speaker.
  2. Too big an instantaneous impulse. This will violently force the voice coil and cone to their mechanical limits and may well break something. For example, the voice coil may break free of the cone.
  3. Too much power at a resonant frequency. As with big an instantaneous impulse, this can cause things to be forced against their mechanical limits or cause a fatigue-induced failure in some item.
  4. And, of course, long-term fatigue-induced failures that can eventually occur even though you're operating well within the short-term limits described in 1, 2, and 3.
About the only one that's easy to quantify is the RMS power limit; all the others are very dependent on the waveshape and frequency distribution.
Atlant 16:26, 13 September 2005 (UTC)

Atlant is on the right track, but I'd like to add more if I may.

The continous power rating of a drive unit (or complete loudspeaker) is the rating to take note of. This should always be an RMS quantity and refers to the continous amount of [wideband] signal power the driver (or system) can cope with while exhibiting reliable operation considering thermal and mechanical limitations.

The peak power rating or peak music power rating refers to the unit's (or system's) ability to cope with [instantanious] short bursts of high levels of input. This is dependent on the capacity of the drive units in question to cope with the heat and mechanical extremes generated in these very short periods. This is why liquid cooling and extended pole pieces (bumped backplates) were first introduced to HF and LF units respectively. Music material is very dynamic and good quality loudspeakers easily cope with dynamic power levels twice that of the continious rating without risk of failure.

Unfortunately, as noted by Atlant, the marketing guys have jumped all over the P.M.P.O rating of loudspeakers and this is often given precedence over the real power handling capacity, continious RMS power handling.

Visor57 09:59, 9 December 2005 (UTC)

External links

Referring to Wikipedia:External links and WP:NOT, it's clear that a massive list of external links is not appropiate.
brenneman(t)(c) 23:15, 26 September 2005 (UTC)

Please do not simply revert changes you don't like. See edit war. Review the links above and provide a reason why almost one hundred external links need to be included in this article.
brenneman(t)(c) 02:40, 27 September 2005 (UTC)

Actually, it's not at all clear that the list of links is inappropriate here. Let's look at the actual language of the article you're alluding to:
1. Mere collections of external links or Internet directories. There is nothing wrong with adding a list of content-relevant links to an article; There is nothing wrong with adding a list of content-relevant links to an article; however, excessive lists can dwarf articles and detract from the purpose of Wikipedia.
2. Mere collections of internal links, except for disambiguation pages when an article title is ambiguous, and for structured lists to assist with the organisation of articles.
But this article ISN'T a "mere collection of links", whether internal or external. There is a long, complete article that precedes the collection of links to which you're objecting. So please don't embarrass yourself by trying to use WP:NOT to justify your deletion. And speaking of edit wars, I'm sure you're aware of Wikipedia:Three-revert rule, right? You're at three reverts in 24 hours right now.
Atlant 13:19, 27 September 2005 (UTC)

I'm quite dissapointed in the tone that has been taken in this. It's very bad form to simply revert someone repeatedly, especially when that person has asked several times for you to come to the talk page. Please actually read Edit war, and maybe have a look at Wikiquette as well, as the language you've used is unnecessary and adds nothing to the discussion.
brenneman(t)(c) 00:13, 28 September 2005 (UTC) Here's a direct dump of text from Wikipedia:External links

1) What should be linked to

  1. Official sites should be added to the page of any organization, person, or other entity that has an official site.
  2. Sites that have been cited or used as references in the creation of a text. Intellectual honesty requires that any site actually used as a reference be cited. To fail to do so is plagiarism.
  3. If a book or other text that is the subject of an article exists somewhere on the Internet it should be linked to.
  4. On articles with multiple Points of View, a link to sites dedicated to each, with a detailed explanation of each link. The number of links dedicated to one POV should not overwhelm the number dedicated to any other. One should attempt to add comments to these links informing the reader of what their POV is.
  5. High content pages that contain neutral and accurate material not already in the article. Ideally this content should be integrated into the Wikipedia article at which point the link would remain as a reference.

2) Maybe OK to add

  1. For albums, movies, books: one or two links to professional reviews which express some sort of general sentiment. For films, Movie Review Query Engine, Internet Movie DataBase, Rotten Tomatoes and Metacritic offer especially large collections of reviews. To access the list of other collections of movie reviews available online, please use this link.
  2. Web directories: When deemed appropriate by those contributing to an article on Wikipedia, a link to one web directory listing can be added, with preference to open directories (if two are comparable and only one is open). If deemed unnecessary, or if no good directory listing exists, one should not be included.
  3. Fan sites: On articles about topics with many fansites, including a link to one major fansite is appropriate, marking the link as such. In extreme cases, a link to a web directory of fansites can replace this link.

3) What should not be linked to

  1. Wikipedia disapproves strongly of links that are added for advertising purposes. Adding links to one's own page is strongly discouraged. The mass adding of links to any website is also strongly discouraged, and any such operation should be raised at the Village Pump or other such page and approved by the community before going ahead. Persistently linking to one's own site is considered Vandalism and can result in sanctions. See also External link spamming.
  2. Links to a site that is selling products, unless it applies via a "do" above.

Excessive list of links

I won't bother going through and putting "3.2" by every one, but if you could note which of sections 1 or 2 above apply to each of these?
brenneman(t)(c) 00:13, 28 September 2005 (UTC)


see KEF website they have some good loudspeaker diagrams. and the technology page

Arguments for following the guideline

In my opinion, 1.4 (PoV) and 1.5 (High-content external links) apply. Loudspeaker design is a highly-opinionated business and while the article is written in a nicely NPOV way, the individual manufacturers have widely divergent opinions as to how to design systems. For example, Klipsh and Acoustic Research disagreed just a little.

And 3.2 is only a close miss, IMO. Most of these sites probably aren't involved in direct sales (especially via the web), which is the usual sort of thing that gets quashed. Instead, these links have each been added over time by a large number of individual editors so it seems a mite presumptuous for you to come along and suddenly act like the Wiki Police, quoting policy at us; I don't see anyone objecting to these links besides you, and at least several of us are defending these links. If need be, we could simply write a Wiki stub article on each of these vendors, provide a 1.1 link, and call your bluff. But that seems like a silly waste of effort to appease one lone editor.

Atlant 19:35, 30 September 2005 (UTC)

Thank you for responding. However, I'd ask you to review WP:CIV before responding again. I'll adress your points in reverse order.
  • WP:NOT#Wikipedia_is_not_a_democracy. But if we are "counting sides", it's hardly overwhelming, two to one, is it?
  • Clause 3.2 leaves no wiggle room. If they aren't in the "do link/can link" list they are out.
  • Clause 1.5 might be a factor in some of these links, but a blanket statement cannot be applied. Pick any ones that can be defended and write "1.5" beside it.
  • Clause 1.4 only applies if this article is reporting that point of view. An encyclopedic entry cannot and should not include every internal divergance over points not in the article. Pick any links that thus qualify, and write "1.4" beside it.
    brenneman(t)(c) 03:39, 2 October 2005 (UTC)
  • B.S. These are not "links to a site that is selling products". Gene Nygaard 04:42, 2 October 2005 (UTC)

Please note (as above) any links that do follow the guideline, if we're following it. - brenneman(t)(c) 03:17, 3 October 2005 (UTC)

The fatal flaw in your logic is the assumption that the guidelines are comprehensive, including every possibility. Gene Nygaard 04:39, 3 October 2005 (UTC)
Ok, ignoring the hyperbole, you're saying this guideline doesn't apply here. I don't have a problem with you arguing that. I've included that as a section below for that very reason. - brenneman(t)(c) 05:28, 3 October 2005 (UTC)

Arguments for ignoring the guideline

Note also that there is lots of wiggle room. What you have cited is a guideline, something we are free to ignore, not a policy. Gene Nygaard

brenneman(t)(c) 03:17, 3 October 2005 (UTC)


P.S. I'd suggest you review WP:CIV (which is a policy, rather than a guideline) yourself, especially the part about "ill-considered accusations of impropriety of one kind or another", because there certainly was no impropriety in Atlant's response. Gene Nygaard 04:51, 2 October 2005 (UTC) Note that what you put in your editorial comment was a more egregious violation than asking Atlant to review it here. Gene Nygaard 05:57, 2 October 2005 (UTC)

  • Ok, there seems to be some hostility here. I'd encourage you to try to understand the intent of WP:CIV. If per your understanding saying "please be civil" is a violation and " please don't embarrass yourself " and "it seems a mite presumptuous for you to come along and suddenly act like the Wiki Police" are not, I think that we are going to have a problem communicating.
    • I saw a page that needed some editorial assistance. I was bold.
    • Two other editors chose to revert several times, in lieu of coming to the talk page.
    • We're meant to be discussing the content, not the contributor. I'd encourage everyone to do so.
brenneman(t)(c) 03:17, 3 October 2005 (UTC)

return of the manufacturers

No axe to grind here, but I'm restoring a big chunky deletion from Nov. 29 or thereabouts which I would hope to be accidental, and I can't tell from reading the above what the final decision on the manufacturers' links was... so I figured it's easier to restore them and then they can be deleted if that was the consensus than not restore them if the consensus was to restore them. That's what happens when folks don't use their words on the talk page! Gzuckier 03:29, 10 January 2006 (UTC)

You cheeky monkey! You certainly could have done it the other way around, asked here first and then put them back if no one objected. ^_^
These were initially external links, and I'd scream all the way to the altar if they cam back. See extensive arguments above. As I recall, when opposition dried up and I recieved a few supportive comments on my talk page, I deleted the links and there was nary a whimper.
I can't see the logic of putting in all the internal links. Does every one of these only make speakers? Several clearly do not. I'm sure that they are relevent, but have we got every speaker manufacturer that has an article?Do we want every manufacturer that has an article? Finally, what they add to the article? {{Category:Loudspeaker manufacturers}} already exits, why don't we use it instead?
brenneman(t)(c) 05:29, 10 January 2006 (UTC)
I see no reason at all why there should be a list of external links to speaker manufacturers in this article. A list of manufacturers adds nothing to the article, it turns the article into a marketing piece instead of an encyclopedia article. If one wants to link to an external page that lists them, that is fine.Ron E
No consensus was every reached, brenneman simply forced his own way and while I believe I was not alone in thinking the links perfectly valid, I wasn't interested in being the only person fighting this battle so I let brenneman have his way.
Atlant 18:49, 16 January 2006 (UTC)

Article Cleanup

Having read the article I think its very much in need of a few changes, none more important than deciding on the terminology to be used to refer to a driver (transducer) and to 1 or more drivers in an enclosure (cabinet) and clear distinctions to be drawn between the 2. I also think the last 1/3rd - 2/3rds of the article could benefit from being farmed off into other articles. Just my 2c but it is a very messy read. People seem to be actively editing so I'll leave well alone for fear of treading on others toes.--Pypex 23:46, 7 November 2005 (UTC)

Cleaned up!

I did my best tryng to clean the article, check it out, I hope the work could be useful

Why not split the Specifications section into two parts, one for Loudspeakers (complete system) and one for Drive Units or Transducers?
Generally loudspeakers have a small set of specifications of interest to the normal user, while the drive units themselves would have substantially more. It would make more sense to break it apart to make the context clearer.
Overall this article has poor focus and needs to approach the topic of loudspeakers from a general scope. The various types of loudspeakers in existance are too many to deal with in detail and should only be briefly described.
Essentially a loudspeaker as a whole is an acoustic transducer, used to covert recorded material from its electrical waveform (in the case of analogue signals) to acoustic waveform. The basics of how this is achieved remains the same regardless of the method of excitation. Only once this has been properly detailed, could one present a general overview of some of the techniques/technologies employed to achieve the above.
References could then be made to technical resources delving into the contriversial guts of LS design ;)
Visor57 10:26, 9 December 2005 (UTC)

Spherical wavefront, not true?

"One problem with loudspeakers is that the original soundwave usually radiates outwards in a spherical wavefront that reaches both ears;"

I do not know of any sound source that has a sphereical wavefront, in the sense that all frequencies are radiated in all directions evenly. What follows seems to be a advertisement for Bose, If there are no objections I would like to remove this part. Iain 11:27, 12 December 2005 (UTC)

Well, by definition, the wavefronts must be roughly spherical once you're more than a small distance from the radiator (because the velocity of sound is roughly uniform in all directions) but you're correct in observing that the perceived amplitude of the wavefronts may vary depending on direction.
But I don't see your point yet so I guess I'll have to go read the cited quote in context. Otherwise, can you be more explicit with your question (of accuracy)?
Atlant 13:20, 12 December 2005 (UTC)
A spherical wavefront is true only if the sound radiator is a point source - this means that as the size of the speaker cone increases the wavefront becomes lobed. This has to do with the sound wave's wavelength (frequency) such that as the diameter of the radiator approaches 1/4th (0.25) the wavelength of the sound wave, the wavefront becomes lobed - i.e., it becomes directional. Rohitbd 15:10, 28 December 2005 (UTC)
Or a spherical source. :-) — Omegatron 02:42, 25 January 2006 (UTC)
Yes. I guess these are the kind Bose has tried to approximate with their 8-sided speakers... Rohitbd 11:27, 29 January 2006 (UTC)
Other people have done it, too. — Omegatron 15:29, 29 January 2006 (UTC)
I agree with Iian here, there are many loudspeakers which attempt to approximate the spherical wavefront. None of which are able to do this perfectly otherwise, as he states, the radiation would be perfectly omnidirectional and coherent. In particular discrete arrays of drivers, such as the bose system, have well documented shortcomings at high frequencies. — Jackocleebrown 12.49, 30 May 2006 (UTC)
I also have a problem with the Cabasse entry. Cabasse are not the first people to try and use co-incident driver technology to improve the radiation of loudspeakers nor do their drivers work particularly well. It would be more appropriate to mention either the Tannoy Dual Concentric design or the KEF UniQ both of which well pre-date and outperform the Cabasse — Jackocleebrown 12.52, 30 May 2006 (UTC)
That's right, Cabasse is not the first. I added it because : I noticed the discussion about the goal of a spherical wavefront, and about Bose (who did not something very exceptional in this field). I would suggest to mention Tannoy and Kef as being the famoust ones to build "first dual concentric drivers". But I think that Cabasse is the only company to build a 3 and a 4 ways concentric drivers. What's more, the measures of these drivers are probably the first ones to demonstrate such an improvement of coaxial drivers over standard ones (less than 3 dB between on axis and on 30° axis responses), plus their article at the AES can be considered as serious fondamental research. So, while talking about spherical wavefront, I would think that Cabasse deserve to be mentioned considering their involvement in this domain... FabgrOOv 14:25, 30 May 2006 (UTC)
The well known 'pulsating sphere' has of course a spherical wave front.--Light current 16:25, 30 May 2006 (UTC)
OK FabgrOOv, good point about 3 & 4 way. I think that you are over-rating the performance of the Cabasse drivers compared to the newest Tannoys and KEFs. I would suggest that BOSE is removed in favour of a paragraph on co-incident loudspeakers including KEF,Tannoy & Cabasse (any others?). All these three have done serious published (AES) research on this subject. This way we retain the link to spherical wave fronts? — Jackocleebrown 14.50, 05 June 2006 (UTC)
The way I see it, the entire section which mentions Bose and Cabasse is should be rewritten because too much emphasis is made on the brand names. If one wishes to discuss speakers with different radiation patterns and their potential benefits and name some examples, that is one thing - but writing an entire section on a certain brand is straying too far from a neutral viewpoint. For example, one can discuss coaxial loudspeakers, their advantages and their shortcomings, then mention a couple manufacturers of said speakers. One can discuss bending wave loudspeakers and their advantages and shortcomings and mention a couple manufacturers. Or maybe we should have a different section for each manufacturer that has published "something" in the ASA or JAES....(that last sentence is sarcasm, folks)--Ron E 00:38, 7 June 2006 (UTC)
I agree with both of you, Jackocleebrown and Ron E. About the over-rating : I'm not sure because the response curves on axis and on a 30° axis were astonishing. But unfortunately I can't manage to find them on the web. I'm not talking about global speaker performance (even if Cabasse is the only company I know that performs comparisons beteween live music and speakers), but about technological improvement. Even if this company is not well internationally known, it did a lot of technological achievements in the past 50 years. For instance their patent about honeycomb membranes is used for the nose of military aircrafts. To Ron E : I did not create the title, just added the two lines after the Bose paragraph, so I agree with you. Sincerely FabgrOOv 08:23, 7 June 2006 (UTC)

damaged speakers

maybe someone chould add something about how they get damaged by too loud sounds. J C 03:48, 7 January 2006 (UTC)

Added the info. Rohitbd 16:25, 18 January 2006 (UTC)

Copying from

Much of this article seems to have been copied from (click 'Loudspeaker'). Njál 03:37, 24 January 2006 (UTC)

You are mistaken. Before making this sort of accusation, a chicken vs. egg question should be considered. Consider rather that this article may have been copied by the audiocircuit people. Having looked at the audiocircuit article, there is content there that I know I personally added to the wikipedia article. That means that audicircuit copied the wikipedia article. Ron E 01:32, 19 May 2006 (UTC)

"70 V" "constant voltage" systems

I just skimmed the article and don't see any mention of "70 V" "constant voltage" distribution systems.[1] Is there an article about this? — Omegatron 02:57, 25 January 2006 (UTC)

Transmission line speakers: Spam? Excessive exuberance?

Heron asks if this new sectionof the article is spam. I think I'd say that it is. Transmission line speakers ain't really nothin' new; horn-loaded speakers share a lot of the same attributes and it could be argued that they are also transmission line speakers. In any case, the recent editor certainly was pumping in the PoV. I think it would be correct to tone this section down squite a bit.

Atlant 19:31, 22 February 2006 (UTC)

The new cross-sectional view

Rohitbd changed the cross-sectional view of a spaker driver and asked if it's OK.

To me, it's fine.

Atlant 19:46, 24 February 2006 (UTC)

Looks fine to me. Can you show the orientation of the magnetic field? — Omegatron 23:48, 24 February 2006 (UTC)
I could...but that risks making the image less clearer...however, if I'm correct, the current is perpendicular to the axis of the coil and so the magnetic lines will be along the axis (vertical in the image). Rohitbd 13:57, 25 February 2006 (UTC)
Yeah, the voice coil is a simple dipole electromagnet, but the magnetic field of the permanent magnet and pole piece is less intuitive because it sort of wraps around like a torus and is concentrated at the air gap. This shows the north pole of the pole piece is towards the cone. [2] [3]
Does a positive voltage push the cone out or pull it in? This says positive voltage is push out. — Omegatron 17:43, 25 February 2006 (UTC)
The accepted convention for a speaker's polarity is that of a voltage which causes the cone to move outward (i.e., generate a positive pressure wave). Basically momentarily connecting a 1.5V cell to the speaker's terminals and observing the movement of the cone lets us determine which terminal is positive. The terminal to which the +ve pole of the cell is connected to for outward motion is the +ve or hot speaker terminal. Rohitbd 21:10, 25 February 2006 (UTC)


Just an observation over a period of time that this article is particularly the target of vandalism, while related articles are relatively safe. Any ideas/reasons/theories why? Rohitbd 10:30, 27 February 2006 (UTC)

All articles get hit from time to time, but I suspect that articles that draw the attention of kids (either because of their own interest in the topic or because their school work requires research on the topic) get it more often. I've never actually talked to a vandal about why they did what they did, so I may be full of it, of course. ;-)
Atlant 12:33, 27 February 2006 (UTC)
Hmm... Rohitbd 13:11, 27 February 2006 (UTC)

Added front cut-away view

I have added a cut-away view of a loudspeaker as seen from front. I thought it might be helpful. Please check if it is ok. Rohitbd 11:20, 28 February 2006 (UTC)

Lindos links

Copied from my talk page (links just put back):

Please do not add commercial links (or links to your own private websites) to Wikipedia. Wikipedia is not a vehicle for advertising or a mere collection of external links. You are, however, encouraged to add content instead of links to the encyclopedia. See the welcome page to learn more. Thanks. AlistairMcMillan 21:52, 1 April 2006 (UTC)

I am very surprised and puzzled by this comment. Firstly, I have added no links to my own private website (I do not own or control Lindos Electronics, though I founded it). Secondly, Wikipedia is full of external links to company sites, often of poor quality. Lindos is a very high profile company in the area of audio measurements, and the articles on its site are very pertinent to many Wikipedia topics. The test sheet database is a novel public resource, built by users, rather like Wikipedia, and hence of great interest to those reading audio topics and something Wikipedians might be expected to support. My personal interest has always been in improving the understanding of audio quality and measurement, and that is my role now, through my own business Lindos Developments, which does not sell anything but has income from IP rights. Perhaps you should have a go at the IPod page. That's pure product advertising for one manufacturer. Then there is the listing of manufacturers on this page. Lindos does not even make speakers!!

Retrieved from ""

from Wikipedia:external links - What should be linked to:
  1. Sites that contain neutral and accurate material not already in the article. Ideally this content should be integrated into the Wikipedia article, then the link would remain as a reference, but in some cases this is not possible for copyright reasons or because the site has a level of detail which is inappropriate for the Wikipedia article.
  2. Sites with other meaningful, relevant content that is not suitable for inclusion in an article, such as textbooks or reviews.

The Lindos links are to independent reviews, relevant to the article in that they are described as 'typical' measured results. The Lindos articles are also relevant as they describe measurement techniques appropriate to loudspeakers.

Firstly your user page clearly states "I am an electronics engineer, and founded Lindos Electronics in 1979." Secondly it is you, and as far as I can tell only you, who has been adding links to Lindos all over the place. Something like thirty or fourty separate pages. And it is you who created the page on Lindos Electronics. Our rules are quite clear on users promoting their own interests here. AlistairMcMillan 17:14, 2 April 2006 (UTC)
This is most unfair. All the links I add are added because they are extremely relevant to the page. You might also note that I work many hours a day writing for Wikipedia and many of the articles you refer to were created by me, often donating material from my writings for Lindos Electronics. The fact that I founded Lindos 27 years ago does not ban me from refering to in on Wikipedia so far as I am aware. How am I 'promoting my own interests' any more than anyone else who adds links to business sites. I am doing hard work to spread much needed information about audio quality and measurement. Please stop undoing it! --Lindosland 17:42, 2 April 2006 (UTC)
All the content you have added to Wikipedia is much appreciated. And note I never touched or deleted the page you created on your own company. However linking to your companies website on around thirty to fourty different pages crosses the line. Please read Wikipedia:External links. Particularly points 3, 4 and 9 and the NOTE under "Links to normally avoid". AlistairMcMillan 17:51, 2 April 2006 (UTC)

I dispute the "30 to 40". The links are to articles, and, as I have explained, a public database. Both are a major resource written by me for the benefit of the industry and the public. The fact that these are on the Lindos website should not bar them from being linked to. I think you should back off now and let others have a chance to check the links and decide. Removing the one serious test result from the iPod site, a most valuable resource, is especially mean. Have you looked at the links. If you were seriously interested in audio topics I think you would see them as of unique value. If all I were doing was putting up advertising links all over the place you would have a point, but I've spent hundreds of hours writing and converting material on audio for Wikipedia and created dozens of ready made pages on the subject. Please put all links back. --Lindosland 18:00, 2 April 2006 (UTC)

Lindos, you haven't acknowledged the Wikipedia policies that Alistair mentioned above. Particularly #9, which says:
a primary policy of wikipedia is that no one from a particular site/organization should post links to that organization/site
I'm not disputing the quality of your articles, but are you going to comply with that policy or aren't you? --Heron 18:37, 2 April 2006 (UTC)
I have already made it clear to him that I do not own Lindos Electronics (it ceased to be mine in 1994). Nor am I an employee of Lindos Electronics. I run my own business Lindos Developments, which is not a part of Lindos Electronic (both were named after my house actually - hence lindosland!). So it seems to me I am not 'from that organisation'.

(copied from talk:lindosland:)

Sorry but when you contribute to Wikipedia that does not entitle you to promote your company. Again please read Wikipedia:External links. Particularly points 3, 4 and 9 and the NOTE under "Links to normally avoid". AlistairMcMillan 18:32, 2 April 2006 (UTC)
Yes, I read those references:-
  • 3 Links that are added to promote a site. See External link spamming.
They were not added to promote a site, they were added for their value as articles. Nothing suggests otherwise. Please note that I always link to the specific article or specification of relevance, never the Lindos main page or selling page.
  • 4 Sites that primarily exist to sell products or services.
Wikipedia is full of links to sites of companies that sell product. The Lindos site is not just for selling. A major part of it is intended as a resource for technical information on measurement, and the sections I link to are intended for education and are not about Lindos products.
  • 9 A website that you own or maintain (unless it is the official site of the subject of the article). If it is relevant and informative, mention it as a possible link on the talk page and wait for someone else to include it, or include the information directly in the article.
I do not own or maintain the Lindos Electronics website. I write professionally, and some of my writing is for Lindos. I have also written for 'The Audio Engineer's Reference Book' which refers to its authors as 'world experts in the field'. Note that as some articles contain sections on things that Lindos invented, like segmented sequence testing, which is a de-facto world standard, it is fair to regard Lindos as the 'official site' for these.

So I do not feel I have breached Wikipedia rules, and I do feel that I am doing a good service for Wikipedia. Given that fact, I do not feel you should be policing so many articles hastily in the way that you are. You should leave the links for others to decide their relevance to each page independantly, with discussions on the talk at each page.

How about a compromise? One link to Lindos per article if you like, and no mention of Lindos in any link as it appears on Wikipedia (as I have largely done on Speakers). I really do want these articles read. They are used as a teaching resource by several universities who's professors (in Audio engineering) have recently contacted us to let us know. Lets get down to their content, not what website they are on. Of course I could move them to another website, or I could have remained anonymous like most Wikipedians, or I could get others to put up the links (as per Wikipedia above) but doesn't that seems less satisfactory than just being open about it all, as is my way? --Lindosland 20:20, 2 April 2006 (UTC)

Thank you for replying so comprehensively. I still think you're pushing it by promoting a site that you are so closely involved with, but I've stated my opinion and now I'll wait to see what others think. --Heron 20:51, 2 April 2006 (UTC)
I've just looked around for other examples, and while they are perhaps not as numerous as I thought, they are there. Take a look at Audio system measurements for example, and you will find that the only external link goes to the Maxim site, with a 'Buy' tag at the top. I will certainly remain more aware of this now. It may be that the Results sheet database should be on a non-selling site, to make it more independant. I note that both you and Alistair seem to have made no contributions to this page, other than things like layout and spelling, and so perhaps that explains why you do not see the great significance of the links to the topic. True independant speaker measurements are rather rare, which is why the database was set up. --Lindosland 21:10, 2 April 2006 (UTC)
Firstly... I really do want these articles read. This isn't a place for you to promote the articles you have written for another website.
Secondly would you please make clear your connection to Lindos Electronics. You say you "do not own or control Lindos Electronics", and "it ceased to be mine in 1994". However the About page on the Lindos site was written by you and dated 2001. The page full of test results is mostly attributed to you and Chris Skirrow (your son perhaps?). The articles you've said were mostly written by you. Okay, so you may no longer own the business but you do seem to be involved to some degree.
Lastly, the normal procedure for situations like this is listed on Wikipedia:External links. The accepted procedure is to post the proposed links in the Talk section of the article, and let other - neutral - wikipedia editors decide whether or not it should be included. AlistairMcMillan 00:36, 3 April 2006 (UTC)

I'm giving in on this, though I am a bit unhappy that so many other links to commercial (and less philanthropic) sites exist on Wikipedia. I now think I was misled by this fact. Linking to the articles seemed logical, since I have actually be combining writing for the Lindos site with writing for Wikipedia, and the Lindos ones can in some cases differ in POV of course. This is not important though. I do think it a pity that I cannot link to the test site database, especially for the IPod. Chris went to some trouble to find someone with the latest IPod so that we could add it to the site. I don't want to go into the details of Lindos much, suffice it to say that it is not nice to be constantly told that I own Lindos when it was actually taken from me in very painful and complicated circumstances connected with a split with my partner and mother of my children. Lindos was in other hands from 1994 until 2003 when it was transferred to Chris by mutual agreement, with me giving him the right to use IP rights which it transpired I still owned (there were legal battles). Clearly I am involved, and don't deny it, but the facts are the facts.

After 25 years in the field I now despair at the way things are going backwards with myth replacing reality in so many things concerned with audio. Chris agrees, and Lindos is very much our vehicle for trying to educate both professionals and the public back to a proper understanding. I do research in buildings in the groounds of my home, some of which feeds into Lindos. I never liked business, and always enjoyed the R&D. That is why it is particulary sad that the test sheet database results cannot be used here to demonstrate the reality of audio (we specialise in measuring in a way that allows fair comparisons). Yes, most (but not all) of the entries are currently by Chris and myself, but that is because it has not been going long. I thought of including test sheets in articles, but that does not seem nice with Lindos on the top. To me it seems better to link to them - I hate advertising. I wonder if links in the form of citations in the text would be acceptable. I could say something like 'the iPod performed well in independant tests' with a citation link added. Would you consider that acceptable? As far as I can see, the rules support that, though you might still say I am linking to a site that I have interest in! I am in a peculiar position if I cannot refer to things I was involvded in, because there are only a few people in the world heading the development of test methods for audio, and I am the only one specialising in 'subjectively valid' test methods, despite having to fight a hard battle in the face of an industry run by 'spec writers' who tell lies as part of their marketing, so inevitably it all comes back to me! If I leave it for others to write, the job will not be so well done. Any further thoughts? --Lindosland 11:27, 3 April 2006 (UTC)

One last point - I've just realised that a clamp down on links began on this page before I came to it, and the rules are spelled out there, including references to the desirability of crediting sources to avoid accusations of plagurism. This works both ways, and I don't want people reading the Lindos site to say 'they pinched that from Wikipedia'! How do you suggest I point out the source, to avoid two-way assumptions of plagurism, if I am barred from referring to a site I have 'interest' in, even when I wrote the source and the article (I'm thinking of the many articles I created at a stroke, not this one of course)? --Lindosland 11:38, 3 April 2006 (UTC)

You can't "pinch content from Wikipedia" because Wiki content is free for any and all to use.
Atlant 12:03, 3 April 2006 (UTC)

Actually you can, if you appear to copyright it, because Wikipedia is only free to use if you agree to adhere to rule that others can use the material you put it in. The articles on the Lindos site are Lindos copyright. If I use similar phrases in writing for Wikipedia then I am granting use of the new article, not the Lindos one. So the Lindos copyrighted article might then appear to be in breach of the Wikipedia agreement. Even though the articles differ, we enter the realms of plagiarism. This is made quite clear in WP guidelines as already pointed out above on this page as follows!

Interjecting an answer...
Actually, you can't (pinch material from Wiki). You aren't permitted to post material onto Wiki unless you have (or grant) permission to allow its absolutely free use by anyone else anywhere else. So if you had appropriate rights in the first place, you waive your claims on those rights by posting the material to Wiki. Material that is freely given can't be "pinched".
Atlant 16:11, 3 April 2006 (UTC)

  • What should be linked to
  1. Sites that have been cited or used as references in the creation of a text. Intellectual honesty requires that any site actually used as a reference be cited. To fail to do so is plagiarism.
  1. High content pages that contain neutral and accurate material not already in the article. Ideally this content should be integrated into the Wikipedia article at which point the link would remain as a reference. --Lindosland 13:12, 3 April 2006 (UTC)

Self-published sources

Anyone can create a website or pay to have a book published, and then claim to be an expert in a certain field. For that reason, self-published books, personal websites, and blogs are largely not acceptable as sources. Exceptions may be when a well-known, professional researcher in a relevant field, or a well-known professional journalist, has produced self-published material. In some cases, these may be acceptable as sources, so long as their work has been previously published by credible, third-party publications. However, exercise caution: if the information on the professional researcher's blog is really worth reporting, someone else will have done so.

With regard to this, I am a well known professional doing R&D in the field. I have been published in reputable sources, eg Focal Press/Butterworth Heinemann. The articles being referenced are published on the web by Lindos Electronics which is a very well known and very reputable organisation represented worldwide. I note that acknowledgement of text used in creating an article must go in a 'references' section, not 'external links', so I will do that. --Lindosland 15:01, 3 April 2006 (UTC)
If you will read the passage you are referring to closely, you'll see it is talking about other people linking to the well-known professional researchers work. It is not talking about the professional researcher him/herself coming to Wikipedia and linking their own articles. AlistairMcMillan 00:54, 4 April 2006 (UTC)

If that were true it would mean that I could not write for Wikipedia, as it says clearly that not to link to reference sources would be plagiarism. I think you are confusing links generally with links to sources used in creation of an article. I read the above section as saying that well known professionals who have been published elsewhere by credible third-party publications can be an exception. They have to be if they are to write for Wikipedia. If you insist on not replacing those links, then I feel you put Wikipedia in the position of seriously plagiarising articles that are copyright on the Lindos site. You also make it look as if Lindos stole the articles from Wikipedia and slapped copyright on them. It's not acceptable at all, hence the emphasis in the rules about plagiarism. I want other opinions on this particular aspect before I will give in on this. --Lindosland 22:33, 4 April 2006 (UTC)

Again, that passage is talking about someone using a professional's website/blog/whatever as a source, not the professional using their own website/blog/whatever as a source. Please please please ask around. You are misinterpreting that paragraph.
Please also read the text under the edit box. Content must not violate any copyright and must be verifiable. You agree to license your contributions under the GFDL. By copying and pasting content to Wikipedia you are licensing that content under the GFDL. If you don't have ownership of that content or permission to copy it here, then is it not you who is plagarising the Lindos site? AlistairMcMillan 23:10, 4 April 2006 (UTC)