Speaker cone material pro's and con's

Eldartford:

Is my lighthearted mention of walking on water considered polemic

Hardly. If anything, a refreshingly light note...!

Here's an interesting response by Mithat Konar, designer of the Biro L/1.

http://www.birotechnology.com/FAQ/index.html

Jim

Dearing...I get your point. But be aware that plenty of highly credentialed engineers/scientists are, at the same time, certifiable yahoos. These guys often publish so called technical papers. And, some great ideas come from people with no formal training. It's your job to separate wheat from chaff.

I second Duke's suggestion! You should definitely get an AES subscription!! (Cone materials are often about balancing of different compromises)

Not everything published in AES is perfect nor is it easily digested. Well worth it for those who seek closer to the truth.

I would expect many Agoner's are AES members, after all, they have an interest in the technology of audio reproduction and the membership dues are modest compared to most high end gear. Think of the advantage of being an informed buyer!

"I have most of the credentials that Dearing was looking for I find it a bit overbearing to suggest that only people with this sort of academic credentials are worthy of respect."

I am well aware of your posts and find them uniformly helpful. I was specific in requesting only references to materials written by qualified people because Audiogon, like other unpoliced public forums, is full of yahoos offering uninformed opinions and other ramblings, which I am not interested in.

Thank you to those who read and thought about my thread, and attempted to respond.

Gregm...Is my lighthearted mention of walking on water considered polemic? Sorry about that. Although I have most of the credentials that Dearing was looking for I find it a bit overbearing to suggest that only people with this sort of academic credentials are worthy of respect.

Greg I understand where JTgofish is comming from. Look at B&W, they pump their Kevlar material as being something really special and unique, Which it is, and the give it a yellow color for added eye catching feature. Good and fine. But how is the other construction, the internal mechanics of the driver, voicing the lower midrange fq's. Personally its not my cup of tea on my JADIS ORCH REFER, a amp well known for its purity on midrange. I bought the 602's cause the wife got sucked in by the salesman.
I had paper cones in the 70's and my speaker for 20 yrs was a pair of philips 2 ways, served me fine in the bass until I came across my currect speaker. I know all sorts of poly cones over the past 30+ yrs, not a one I like.
The only material that i came across that competes with my currect sopeakers magniesum material was the Cabasse with its white foam material. But the Excel has the Cabasse beat in the bass and also the internal voicing from the "motor" of the lower midrange fq's.
So Jtgofish is right, some labs will come out with a marketing ploy to try to convince you "our new spaceage materail is something unique and like nothing you ever heard in your life". Gimmicks are a part of this trade. Cone material is only one part of the speaker, how all the other parts come together give the driver its particular voicing, its nuances and "flavor". Someone mentioned the old cliche "no driver is perfect sound" well obviously we all know that a live orchestra/jazz band is one thing, our speakers will have limitations. But we strive to get as close to original as possible. Some are closer, others are further away. Some like thise music to sound one way, others another. I've beenb seeking 30 yrs for what I hear in the Excel. Others prefer Vandersteen's sound. And so on....

Any debate on cone material is really only a contribution to the smoke screen which feeds audio marketing departments

Maybe.

BUT, the thread starter only asked for INFO and pointers, for goodness sake..

I fail to understand the pursuant polemics...:)

The point is that there appears to be no correct sounding cone material.They all have their sonic signature and once you become aware of this it comes down to choosing the one which causes least offence rather than one which is "best".
Cone/box speakers are such flawed devices that to expect unflawed or uncoloured performance from them is niave.Of course it is not in manufacturers interest to tell you this-although I am sure most experienced designers employed by them are well aware of it.
Any debate on cone material is really only a contribution to the smoke screen which feeds audio marketing departments.

Aolmrd1241...My water-walking is OK on the ocean (salt water) but I sink in to my knees on fresh water.

Eldartford - Is it also necessary to walk on water>>> LOL ;-)...

I come from a time when all speaker cones were paper. We were hands-on audiophiles and we spent a lot of time "doping" cones in an effort to change the sound. We glued on balsa wood (lightweight) strips to stiffen the cone and prevent breakup. Then we glued on weights to lower the resonant frequency (go figure). We did things to loosen up the cone suspension.

Nowadays driver manufacturers use various cone materials and they address the issues which we audiophile sought to deal with aftermarket. I see no reason for an audiophile, or a high end speaker manufacturer to dope a cone. I suspect they do this just to say that they have some proprietary secret that makes their product sound better. In truth, they have simply selected the wrong driver (maybe because it is cheap) or they have screwed up the crossover network and are applying a band aid.

Cone material is only one part of the driver. Look at the Seas Excel driver with its magnesium material, seems to be something in between a paper and poly. But also hold the driver in your hands and ck out the craftmanship of the driver, the copper phase plug/magnet, the entire construction is something to behold. dang near work of art. Sounds good too!
I've never liked poly (plastic!!) cones. I had a great paper cone speaker until I came across the Excel. Next best cone material I ever heard is the french line called Cabasse, its a white 'form" material, not sure if they make it anymore. I heard their midprice line and thought it was OK, it was poly I believe. Also mention goes to B&W for their Kevlar, not bad, but I don't like the midrange that comes out the driver, too boxy/warm/muddy/attacking/fatiguing.

Let me apologize for the rushed post. That first sentence makes no sense to me either. My point is you can make general staement in isolation about the material used. For instance so many mill of a known alloy of aluminum will weigh a certain amount and be stiffer than many doped papers. The question is what parameters are vital. Do you think calling our non phyical engineers or non compound chemist's contributions blather? Speakers are tricky to get right. The materials used make a contribution but in the end it is the sum of the parts. Good speakers obey the fundamental rules and then the builder, who is on a path of good intentions hears them and spends a lot of time voicing them. It is an imprecise science.
In order to give this fellow a reference that is truly helpful you have to ask what does he ultimately want to know. The early speaker design books tell you more about what the resultant sonics are likely to be. I personally don't think dustings of diamond on a cone or Be or Ti fundamental.

AES articles are unlikely to meet his intelligble-to-layman criterion, unless he could find a general review article. In my experience, peer reviewed articles in professional journals are aimed at readers active in the field.

db

Mechans:

If its the sonics you are interested in then a discussion (...) is meaningless

You are wrong. The cone & its material influence the sound you get -- and as such, are part of the parametres (along with T/S which I assume you;re alluding to) one takes into account when designing loudspeakers.

All the guy's asking is for some refs... :)

Why are concerned with the material used when it is the If its the sonics you are interested in then a discussion hghly scientific of course of the tensile strength of kevlar of a particular type versusthat of paper is meaningless. The entire driver parameters may be what you want that tells you more objectiveinformation.
Technical talk of one material over another is blather with very cone/dome/oval, square, specific data. You might want to know the Qts. for instance, this could be high or low do you know what you want? Because there are advocates for both types depnding on the cabinet design. etc. There is paper that is like leaden cardboord and there is paper which is siff and very light. What question are you interested in answering? Look at the raw driver sites they frequently give specs. You didn't include the Plasma Flame tweeter transducers in your post. But that's a hot topic.

The cone material itself is not as important as proper damping material applied to any selected material.

This is why standard mass produced drivers as used in expensive speakers like Avalon,Wilson and Sonus Faber invariably are "modified" by these makers to dramaticaly improve sound quality.

Apparently if you apply specially prepared venomous snake oil to the internal cone surface and bio dynamic bull manure from beer fed Wagyu bulls to the front of the cone,the improvement in performance is staggering.This has to be done in the right lunar cycle of course.

A quick primer and some ideas from the ldsg. Then, definitely subscribe to AES: it's a serious organisation and their papers are as intersting as they are thorough.

If you want a well-written discussion of cone materials by a professional engineer who is not writing on behalf of his employer, I suggest you join the Audio Engineering Society. I did, and to me access to their published papers is well worth the hundred-something dollars per year.

I could write about some of the pro's and con's of different diaphragm properties and profiles, but I don't meet your criteria, being both a manufacturer and non-engineer.

Duke

Is it also necessary to walk on water?