Sean...Lighten up! Dogs eat homework every day! I, and I am sure many others, have been in the situation of losing work for one reason or another, and the worst part is realizing that other people will be skeptical of our explanation. One time I lost a 20 sheet PowerPoint presentation while putting finishing touches on it after hours the night before the business trip. No choice but to suck it in and stay up all night doing it over again. As usual for a second time around it actually came out better, but I never told a soul that I had screwed up.
When I write long Audiogon posts I do it first in WORD, and then copy it into the thread. Why? I learned the hard way. BTW this also gives you a spell checker for words like "analogue" :-)
We look forward to your next dissertation. |
El: I don't know if that was meant to be humorous as a comment about modern day technology and how things get "lost in the system" or to say that i'm bullshitting and didn't do any of the work i.e. an excuse. Believe me, i invested a great amount of time in what i lost and it doesn't make me happy. Sean
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"The dog ate my homework"...updated. |
I spent quite a long time typing out a very thorough yet somewhat easy to follow response to the above about Qms, loudspeaker design, resonances, the amplifier / speaker power transfer interface, etc... While attempting to perform another function on my computer, i somehow managed to shut down multiple windows at one time. One of those windows was the Agon post i was working on. Needless to say, i'm quite frustrated and not up to trying to re-do it right now, so it will have to wait. I apollogize for the delay and will try to get to this soon.
As a side note, good news from my ear doctor today. He told me that they can stay on the sides of my head, no need for removal as of yet : ) Sean
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Cdc: I've got to head out to the ear doctor and then off to work. I'll try to explain why Qms is important later tonight. What i'll have to say is controversial amongst most speaker designers / engineers, but the facts present themselves once one does research on the subject. Even so, many that are rooted in their beliefs refuse to see the light, just like those that told you that it didn't really matter. Sean
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Hi Sean, I dunno, that was what I was told. I justified it when looking at total Q. The electrical Q seemed to have a greater impact on Qts than the mechanical Q did.
Anyhow, does this bamboo material driver look like a good choice? It retails for about $35 each. I can't put up response curves but above 14k there is an 8db plateau from 15-18k - that doesn't look very musical or accurate to me. |
Cdc: What makes you think that Qes is any more important than Qms, especially on a "full range" driver or woofer??? I see this line of thinking expressed all the time, yet i can't understand the logic behind it. If this were a driver specifically designed for use over a limited bandwidth where resonance would not come into play at all, it wouldn't be as big of a deal. With a woofer and / or a tweeter, where the resonance does come into play within the audible bandpass of the driver, this is a completely different story.
My guess is that most people don't understand what a higher Qms brings with it, hence the lack of concern in this area. This is exactly why most low frequency drivers, especially "American made" ones, are as poor of a performer as they are. When you start studying power transfer characteristics, transient response, ringing, etc... it becomes apparent just how important a low Qms really is. Combining a high Qms woofer with a vent, which also reduces control and damping, is a sure-fire way to lose all forms of bass definition and transient response. Sean
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Puzzlecoat painted on paper cones can improve the sound. Too much can roll off the highs (relatively speaking, as in causing midrange loss) too much. |
Tang-Band has a full range 4" driver made from bamboo coming out in May.
Qms = 1.499
Qes = 0.484
Qts = 0.366
BL = 4.80
Mms = 3.49 g
Compared to their W4-655sa 4" paper driver:
Qms = 4.35
Qes = 0.35
Qts = 0.33
Electrical Q being more important to damp than mechanical Q. But TB's typical paper Qms is no lower than 2.80. So the bamboo damps very well indeed. |
Bobby's response is beautiful as it is both to the point and technically excellent. Then again, he speaks from years of first hand experience in the field of speaker design and manufacturing, so he should know these things. Obviously, he does : ) Sean
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Used to have a pair of paper cone full range speakers. Spectrums, I think they were Dutch, taken over by Fisher at some point. Great speakers. They had been my grandfather's with an old NAD integrated. Both came out of a screening room at CBS 60 Minutes when they revamp'd. Wasn't sure about the ensemble when they got shipped to me... paper, 25 years old, etc. My intro to hi-fi after my grandfather passed away. Lasted me five years even so, 30 years total, and paper cones are supposed to be easy to destroy. After an hour with them I had been converted. |
Reinforced paper cones seems to be one of optimal choices, dont know to which extend slicing the paper etc. is just hype... ?
low-end would be poly-propylene materials... it has a smoother and deeper (comparable to paper), but clearity and precision is very bad - PP simply flexes too much when playing bass, making distortion the rule rather than the exception. Surprisingly many manufactures markets their pp cone woofer as quality - showing of their smooth response curves and low-end fs values... and only very very few gives you any idea of rated distortion and power compression, which is much more important in a bass unit.
from what I've heard aluminium is not optimal when it comes to timbre, i.e. it makes the sound less natural, and Kevlar tend to have a less uniform response curve than paper, but have a deeper fs value, ideal for non-vented enclosures, but who uses that for bass?
Anyways the point being that its a trade off (between many things, where paper still seems to posses the best of each.
I myself have two 15" paper cones - one $50 that sounds like crap compared to my $500 JBL 2226 G 15", but that would be expected - paper cones comes in many varities too...
A. |
Paper is a low mass low loss material. Paper cones have better transient reponse ang higher mechanical Q compared to plastic/polymer alternatives. They have higher efficiency. But they may have resonances which must be taken care of at crossover side. The envoiremental robustness is achieved by surface treatments. But since it is a compressed material it will loose it's structural rigidity in time. High tech marketting jargon can also be applied to parper cones by giving exotic names to pulp mixtures etc. |
I have a pair of S.A.P. J-2001 speakers that have two 12" paper cone woofers. While some may view paper cones as "old" technology, that does not mean it is inferior in any way. This speaker also has a horn midrange, but the compression driver has a titanium diaphragm ("new technolog"?). Both the woofers and the midrange utilize old fashion Alnico magnets. I believe the designer utilized what works best, not what is fashionable and current. At about $22k, I don't think the "cheapness" of paper was a consideration.
A friend of mine spends a small fortune collecting as many Western Electric or Altec paper coned drivers (515 or 555 or something like that) as he can get his hands on. The cones are so old they crumble if touched. The sound, however, is very lively and articulate when these drivers are used in his full-range, multi-driver designs. |
The majority of audiophiles prefer paper over other materials due to its "natural" sound...however...hi end speakers with paper drivers are often coated or a poly-blend...hence no relation to lower end speakers... |
Hey Marco.
Those headphones are sweet!
I think they would look great with a head gear orthodontic apparatus.
I dont know if you are joking around or not, but they look truly rediculous. They look like they might sound kinda "Tinny" HAHAHHAHAHAHAHAHAHAH
Anyways, i guess if they sound good....
i think i will stick to speakers. :) |
The reason why many of us like and use pulp type cones is that they provide excellent self damping charateristics. That being the case, less of a filter can be used to accommodate the transition into the next driver. There is no doubt that some of the more rigid materials do certain things better but they also ring harder and require more filter to remove the resonance. IMHO, in my high resolution designs designs, I have found that component coloration (sounds and resonances of capacitors, inductors, resistors and wires) are much more objectionable than the problems that reduced rigidity generate. Then again, my drivers are more heavily damped and use carbonfiber to add rigidity the cone. Low mass, excellent self damping potential and rigidity, the necessary mix IMO for a superb transducer.
Bobby@merlin |
,,,There are paper base drivers in the multi thousand price tag speakers as well,,,,
Scan Speak and Morel make awesome paper treated drivers, and so do many other manufacturers I am sure...paper is easy to model and is more predictable, and all more well rounded.
I love paper treated drivers sound (the ones well made and designed of course,,especially for mid and midbass..
I actually have some JBL L-96's which have arguably the best midrange driver ever made, and its paper... |
Dunlavy used them on all his speakeres including some very expensive ones that recieved rave reviews for their accuracy. He claimed that they rang less and didn't store energy as much as more expensive, high tech alternatives. |
To add my 2 pennies, paper is used because of its lightweight(for fast transcient responses and dynamics)characteristics and ability to minimise sound coloration. Though its starting to finally show its age as there are new materials that will far exceed paper in terms of sound quality,output etc. Titanium alloy being one of them, but you dont see many speakers with titanium cones due to expense to mfg. them. But dont shy away from speakers that use a pulp cone. There are too many great sounding speakers that use them. |
Those who look inside high end speakers are often surprised by what they see. Not only are the cones sometimes paper, but the entire driver may be elcheapo. Wires too. I hasten to add that not every manufacturer is like this, but more than you would suspect.
What does it mean? Mainly that driver "quality" is more about reliability, and power handling capability, than sound, and the design of the overall speaker system, especially the crossover, is of great importance. Good drivers can sound lousy, and vice versa.
There is paper, and there is paper. Paper is a laminate of wood (mostly) fibers, and can be a very sophisticated product. One wooden product that amazed me when I learned of it is the bullet-shaped nose fairing on the submarine-launched ballistic missiles. It is made out of laminated wood, similar to a rowing shell. (I would have expected fiberglas). It is light weight and very strong: it supports the weight of the entire missile when it is hoisted into the launch tube. |
speaker cones made of paper(sometimes from the very same suppliers) are used in hi end and cheapo models. thw same goes for stranded copper wire. life isn't fare. |
Not true at all. "Paper" tends to denote taking the cheap way out but is in fact a complicated mess of fibers, polymers, resins etc., engineered for light weight (has to react quickly), high rigidity (prevents deformation) and longevity. Paper's been a proven performer for decades - only recently have things like Kevlar and metal cones been introduced, and while they have advantages and disadvantages over paper, they alone do not make a speaker high end by virtue of their properties. |
You know I don't photograph much audio gear. So when Motts approached me to photograph their new idea for headphones I was a bit sceptical when I first saw them. Boy was I wrong. They may not be comfortable but the audio experience is like nothing I've ever tried. Brings back memories of the good old days when I was a kid. Every time I use them though my wife complains I smell like tomato paste! So I was thinkin', why, for Pete's sake, don't the speaker manufacturers catch on and use these materials for their drivers?! I'm guessing that once they catch wind of these babbies Dixie Cups will be giving them a run for their money....paper is lighter and can move much faster after all. Motts SchaMater ReferenceMarco |
Paper is the most natural sounding to my ears. But it lacks dynamics and high volume capability.
To add to TWL's post, I think paper is good for absorbing unwanted resonances in the driver. Better than metal and polypropylene (that's a low end material Epos being an exception - there's always an exception) |
Cluesless is right, the paper cones are for the high end radio shack speakers as well.
TWL, Just kidding! :) |
said above: >> I always thought paper cones were for low end Radio Shack speakers.
Nope.
Sincerely
I remain, |
I prefer paper over any other cone material that I've heard. It is very light and very rigid for its weight. Nothing is perfect, paper has its flaws just like any other material. However, the statment that paper is only for low-fi speakers is very incorrect. |
I don't know much about this, but some mfg'ers as well as others in the know, believe that pulp (not paper) produces a more refined sound than say those made of kevlar, aluminum, etc..
I don't believe you should consider this to be an issue. Provided the mfg'er is truly producing a quality-oriented speaker.
-IMO |
