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  • Guest
    Guest replied
    Re: Cone materials

    Look forward to hearing, or seeing, how they turn out.

    Leave a comment:


  • curt_c
    replied
    Re: Cone materials

    Originally posted by tpremo55 View Post
    I'm going to guess:

    Titanium (like the TB 1337s in the Statements)
    - and -
    Ceramic (like the Accutons in the Uber-Exclamations)

    ..but just a guess...:D

    Leave a comment:


  • tpremo55
    replied
    Re: Cone materials

    Originally posted by floppygoat View Post
    Which materials were these cones made of?
    I'm going to guess:

    Titanium (like the TB 1337s in the Statements)
    - and -
    Ceramic (like the Accutons in the Uber-Exclamations)

    ..but just a guess...:D

    Leave a comment:


  • Guest
    Guest replied
    Re: Cone materials

    Which materials were these cones made of?

    Leave a comment:


  • curt_c
    replied
    Re: Cone materials

    Originally posted by romanbednarek View Post
    Non-linear distortion is best observed by looking at harmonic distortion measurements but extensive knowledge of motor designs as well as how the cone might react to a certain motor (for example metal cones "amplifying" the distortion when it falls on the resonant frequencies) can help you predict which motor designs might have advantages. Some motors are better at staying linear over a wider range of power levels (greater excursion in particular). I won't go any further than that because I don't have enough experience on this topic.
    Originally posted by floppygoat View Post
    So far, great post guys. It seems that poly and paper cones have the lead!

    Leave a comment:


  • romanbednarek
    replied
    Re: Cone materials

    Originally posted by 3way View Post
    Modern treated paper cones like Scan Speak slit paper Revelator with carbon fibers sound good to my ears. I have a pair of B&W Kevlar 5" midranges with great detail but fatiging even with a notch filter, just like all my metal cone designs. Superior sounding woven fiber cones will likely require a multi-million dollar machine to manufacture Kevlar synthetic aramid fibre with a variable weave to be stiffer near the voice coil and more absorbing near the surround. I'm watching for new dampening technology on kevlar and metal cones.

    http://www.bowers-wilkins.com/displa...788&artid=1417
    My friend has a pair of speakers with those Kevlar drivers in them but they use them in an interesting way. Those Kevlar midranges do NOT have any surrounds and rely on the flexing of the cone which allows them to have better off axis performance higher in frequency because the higher frequencies only come from the center of the cone (dispersion is good because when off axis the distance between the far side of the radiating part of the cone and the near side is shorter meaning that the wavelengths were the two sound sources will be 180 degrees out of phase and cancel will be shorter). This is quite the opposite of a metal cone which doesn't flex at all and its off axis roll off occurs at the lowest possible frequency and has a very abrupt transition from pistonic behavior, but some people claim that true pistonic behavior is best even if you have to cross lower.

    Back to the B&W Kevlar cone midrange... they still have a nasty high Q resonance peak and I've always felt that B&W used too high of a crossover frequency with their designs using this midrange (at least with the B&W Nautilus 802).

    Leave a comment:


  • 3way
    replied
    Re: Cone materials

    Modern treated paper cones like Scan Speak slit paper Revelator with carbon fibers sound good to my ears. I have a pair of B&W Kevlar 5" midranges with great detail but fatiging even with a notch filter, just like all my metal cone designs. Superior sounding woven fiber cones will likely require a multi-million dollar machine to manufacture Kevlar synthetic aramid fibre with a variable weave to be stiffer near the voice coil and more absorbing near the surround. I'm watching for new dampening technology on kevlar and metal cones.

    http://www.bowers-wilkins.com/displa...788&artid=1417

    Leave a comment:


  • romanbednarek
    replied
    Re: Cone materials

    Originally posted by floppygoat View Post
    Realistically, which cone materials are best for sound quality? I have always thought that it was paper, having better dampening, low distortion, and a flat response. However, someone has caused me to doubt this. I understand that this is only one of the many variable when considering sound reproduction, but if you had identical drivers, except for the cone materials, which would create better acoustics? This inquiry is not limited to an "the" best material, just wondering which are some (3-5) of the best to consider in a system and why?
    Regarding the concept of drivers using the same motor but different cones I have a few examples at the links below (but keep in mind that I put these pages together quite some time ago so my recent responses may be more accurate regarding the explanations).

    CA18 vs L18

    http://www.rjbaudio.com/Audiofiles/c...materials.html

    XT18 vs XG18

    http://www.rjbaudio.com/Audiofiles/V...20vs%20XG.html

    Just keep in mind that there really isn't a clear cut answer to your question because a lot depends on the application of the driver as well as the preference of the listener.

    Leave a comment:


  • JRT
    replied
    Re: Cone materials

    Originally posted by floppygoat View Post
    Realistically, which cone materials are best for sound quality? I have always thought that it was paper, having better dampening, low distortion, and a flat response. However, someone has caused me to doubt this. I understand that this is only one of the many variable when considering sound reproduction, but if you had identical drivers, except for the cone materials, which would create better acoustics? This inquiry is not limited to an "the" best material, just wondering which are some (3-5) of the best to consider in a system and why?

    Beryllium is a very good diaphram material.

    Acoustic Properties of Beryllium

    Voice Coil January, 2004 reprint

    Voice Coil May, 2003 reprint

    Voice Coil September, 2001 reprint

    A midrange example, Usher 0541A (select "Frequency Response & Impedance" and "Distortion" to see those graphs in the Adobe Flash app, not sure what level was used in measuring nonlinear distortion):
    http://www.usheraudio.com/driver-0541A.html






    .

    Leave a comment:


  • Guest
    Guest replied
    Re: Cone materials

    Originally posted by thenoid View Post
    Far more important to "better acoustics" is the implementation of whatever driver you choose to use. Overall driver design. enclosure design, x-over design, listening environment (room acoustics), etc can effect your sound quality much more than cone material...usually speaking. Not to mention that everyone hears and appreciates things differently which makes it extremely difficult to pinpoint a 'best" in most audible situations.

    If you are starting out, lurk on the boards here for a while, keep asking good questions, take a few proven designs and build them. Once you feel comfy enough, jump in a design your own with your own goals in mind and YOU tell us what material sounds best in your design and why. That's the fun in it all...

    Noidster
    I have built several of my own systems. I also addressed the variable issues you mentioned above. I also stated my personal preference and why. So far, great post guys. It seems that poly and paper cones have the lead!

    Leave a comment:


  • mike1234
    replied
    Re: Cone materials

    I can only postulate why (probably damping) but, as a general guide, I tend to prefer natural fiber drivers on frequencies above 500 Hz or so. Below that it doesn't seem to matter to my ears.

    Leave a comment:


  • romanbednarek
    replied
    Re: Cone materials

    With all of this talk about drivers, cone materials, motor design, response plots, etc. there is one important thing that I forgot to mention...

    Judging a speaker based on measurements, plots, crossover design, cabinet design, etc. without hearing it "can" be like trying to determine how beautiful a painting is by hearing or reading a description of that painting (type of canvas, subject matter, type of paints used, colors used, artist, etc.) without actually seeing it for yourself and remember the concept of beauty being in the eye of the beholder which can relate to the concept that not everybody likes the same type of sound from a set of speakers (this somewhat supports the weakness of the metaphor not supporting the fact that some speakers are better suited to particular kinds of music or recordings in the way that they have to convey a work of musical art through the electromechanical transformation).

    Leave a comment:


  • romanbednarek
    replied
    Re: Cone materials

    Originally posted by tpremo55 View Post
    Thanks Roman and Curt. Great info.

    In processing all this data and considering the variability of a driver of any given material, I am looking for the best ways to establish the specific characteristics of a finished driver. I am sorry to say that I am not aware of any of the T/S parameters that might suggest the stiffness of a cone - maybe there is one. Certainly freq and impedance plots speak to other considerations, and I recognize that CSD plots can identify frequencies of ringing or resonance. But what else should we be looking at? How do we know that a driver (of certain cone material) will perform optimally with respect to cone material/motor system influences in a given range. Is there any way really without measuring distortion?
    I don't think that the T/S parameters tell much about the stiffness of the cone. Looking at the frequency response and impedance response plots of a driver can be very helpful. Usually the degree of damping or stiffness of a paper cone can be seen by the magnitude and Q of peaks (high Q means tall sharp peak, low Q means low wide peak) and stiffer, less damped paper cones usually have higher Q peaks. The impedance response can be handy as well because irregularities in the impedance usually point out a resonance or something "funky" going on in that region, but looking back at the frequency response usually reveals what is happening at that particular freqeuncy. Most of the time CSD plots don't tell you much because any linear distortion (frequency response peaks/dips) can be translated to CSD and peaks show up as a tone lingering in time with the higher Q peaks lingering longer (hence my previous response about metal cones and how the ringing that they produce may be more noticeable due to the sustain). Most linear distortion within the passband of a driver can be fixed with the crossover as long as it is a peak in the response, not a dip (because passive crossovers cannot produce narrow band gain), but the notch filters required to fix a peak are limited in how you can shape the notch to fix the peak and may cause dips outside of the notch range or not notch the peak ideally. Some drivers have linear distortion within their passband (below the point where typical cone resonances occur) sometimes due to interactions between the cone and the surround (I think this is the case of the Vifa XT18/XG18 even though I'm still a pretty big fan of both of them). I think that some of the Usher and Scan-Speak drivers have this issue as well. I better wrap this paragraph up here before I walk too far into territory that I really lack confidence in my knowledge.

    Non-linear distortion is best observed by looking at harmonic distortion measurements but extensive knowledge of motor designs as well as how the cone might react to a certain motor (for example metal cones "amplifying" the distortion when it falls on the resonant frequencies) can help you predict which motor designs might have advantages. Some motors are better at staying linear over a wider range of power levels (greater excursion in particular). I won't go any further than that because I don't have enough experience on this topic.

    I hope to hear other responses to my post to either correct something that I have said or expand upon topics introduced.

    Leave a comment:


  • tpremo55
    replied
    Re: Cone materials

    Originally posted by romanbednarek View Post
    Regarding stiff poly cones, I was thinking about the ones that Audio Technology produces but even those seem like they have quite a bit of damping. Others that come to mind are Dynaudio and Morel. I think that part of the problem with poly is that it has a poor stiffness to weight ratio. A friend recently told me that paper cones used to be known as having the best stiffness to weight ratio but this may have changed in recent years with a wider range of cone materials showing up.

    I'm guessing that you misread the name in the LSDC and that it really says "Beranek" who is much more famous than I, but correct me if I'm wrong (I have an older version of that book that I bought back in the late 90's).
    Ah - I have a pair of the Dynaudio 21W54s that I used to have in a 2-way design and am currently building a 3-way with them. I had to replace the foam surrounds, but they pack a nice punch in the mid-bass region. I've always liked their sound. However, I'd say that the RS225 with their aluminum cones are a tough act to beat (and for a lot less money).

    Here is the specs on the 21W54 - interesting statements such as "Many years of lifetime have branded this to be the most rigid and most precise 8" woofer"

    http://www.gattiweb.com/images/dynaudio/21w54_data.pdf

    You are correct (of course) - Beranek was quoted. When I read it shortly after reading your post my mind made the jump - besides, the similarities in your name and interests are considerable for the casual reader...

    Leave a comment:


  • romanbednarek
    replied
    Re: Cone materials

    Originally posted by tpremo55 View Post
    For instance?

    Thanks again for the long explanation. Are you the same Bednarek that is cited in Vance's LSDC in the cone node patterns section?
    Regarding stiff poly cones, I was thinking about the ones that Audio Technology produces but even those seem like they have quite a bit of damping. Others that come to mind are Dynaudio and Morel. I think that part of the problem with poly is that it has a poor stiffness to weight ratio. A friend recently told me that paper cones used to be known as having the best stiffness to weight ratio but this may have changed in recent years with a wider range of cone materials showing up.

    I'm guessing that you misread the name in the LSDC and that it really says "Beranek" who is much more famous than I, but correct me if I'm wrong (I have an older version of that book that I bought back in the late 90's).

    Leave a comment:

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