Cone Material Discussion

I am interested to hear what everyone has to say about the different cone materials. Specifically for the mid range

I think it would be very interesting to hear everyone's subjective and objective findings between some of the newer materials.

I have researched this independently and have only really seen discussion between paper and metal.

I am personally interested in if anyone has experience with the Textreme drivers. I am considering spending some extra money on the mid for my next build. Its either going to be a higher end mid, like the textreme, or its going to be a 4 way with some overlapping drivers that allow me to use LR1 or LR2 crossover networks. Likely domes for the 800-20k hz and cones for the 20-800hz

Has anyone heard any of these higher end cone materials? I wonder if its marketing hype or if they actually sound better. I also have seen that the IR, FR, and waterfall don't tell the whole story. I don't know a way of taking a spectrum burst. I have heard that tells the rest of the story.

Some materials I would suggest discussing that I see:



  1. Paper
  2. Treated paper
  3. Hexacone - Eton makes this
    https://www.madisoundspeakerstore.c...-4-212/c8/25-hex-symphony-ii-4-bass-midrange/
  4. Carbon fiber - Not sure if Textreme counts as carbon but it is a carbon weave
    https://www.madisoundspeakerstore.com/approx-5-woofers/satori-5-mw13tx-4-textreme-cone-woofer-4-ohm/
  5. Metal - aluminum specifically but if there are other let me know
  6. Magnesium - Scan Speak has some of these.
    https://www.madisoundspeakerstore.c...el-w15cy-001-e0015-5.5-magnesium-cone-woofer/
  7. Egyptian papyrus - this would be the Satori line
    https://www.madisoundspeakerstore.c...13p-4-5-egyptian-papyrus-cone-midrange-4-ohm/
  8. Ceramic - SB Acoustics has one of these that looks interesting
    https://www.madisoundspeakerstore.com/approx-4-woofers/sb-acoustics-sb12cacs25-04


    I am interested to know what you have listened to, difference in sound between materials, if any of the materials are worth the extra money for the increase cost of manufacturing.

    Lets please not get into any arguments and ride the thread off the rails.

 
Note the SB ceramic are actually aluminium with a ceramic deposite on them (NAC and CAC are almost identical), for true ceramic have a look at Accuton.

On the Paper side Scanspeak have some some interesting things by curing the cone and then gluing them back to get her in their Revelator and Illuminator series. the 12MU is often lauded as one of the best midranges.

Just a couple of extra thoughts.
 
Interesting. So they are only partially ceramic. Seems like almost more work to develop a deposition process than just to make it fully ceramic

I have looked at the 12MU. It looks very promising. It seems a lot of the high end OEMs have landed on this driver as well. I see these about as much as I see the Textreme drivers. I am sure they have listened to everything in their driver selection process.
 
As an observation, there's no such thing as an LR1 filter -by definition 1st order is Butterworth.

That apart, if (if 😉 ) the driver remains purely pistonic over the operating BW & any relevant effects from stopband modes are dealt with, then the cone material itself is inaudible: no resonance = nothing to hear on that particular front. Most of the time though this only applies to rigid materials -semi-rigid or 'soft' types usually have some form of TL modes going on in their operating BW, or the effects of them which can be audible in various ways.

Re the SB units, I'm not sure but I suspect it's less an addition / deposition than a conversion process (plasma electrolytic or similar) of the outer layers of the base substrate from aluminium to alumina.
 
I havent tried the Satori Textreme drivers, but the slightly less expensive Satori hard cone paper drivers are AMAZING for midrange production, and very easy to work with on the crossover design due to their smooth cone breakup behavior. You can use 1st or 2nd order crossovers with them and be very comfortable with the outcome.
 
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SB don't dispose ceramic on their cones - they electrocute them for a while to make alu go to ceramic.... Is it not SEAS that do magnesium?

Plastic?

//
Super cool.

Yeah, I mispoke. The magnesium is SEAS. I've seen these used in some OEMs. They look pretty cool.

The FR leaves a bit to be desired but the 5" is on sale at Madisound right now
 
SB don't dispose ceramic on their cones - they electrocute them for a while to make alu go to ceramic
Yeah. I is my understanding that SB uses spark deposition to transform the top aluminum layer to aluminae, a ceramic composite.

"Spark deposition
An immersion-based process that uses an electric waveform to combine the aluminum with an acid-based electrolyte to create a ceramic oxide coating. This coating is resistant to corrosion and wear. "
 
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magnesium is SEAS

It would be a magnesium alloy. It is very floppy and very flammable. Ignoring the floopy dome, it would be fairly easy to find yourself playing nloudly and the dome catching fire spetacualliy.


Of the 8 you list there are 3 paper cones. There are thousands and thousands and thousands of paper receipes. Paper from wood, cloth, silk, wool, hemp, manilla (pseudo-hemp), wood itself.

Like the metalcones which are all likley to be alloy, papers are a blend.

Plus, shape, cone profile, mass, much more just talking about the cone. And then you have to consider the other compromises a designer must make.

All this makes for a fairly limited amount of real info.

You might be able to make some generalizations — each with multiple counter examples.

For instance a stiff cone will tend to have ringing issues.

But note: if you take the Alpair 7.3 (Al, mg, + more alloy), vrs the paper cone version A7p. The metal rings a bit, the paper rings more. Coating the paper (AFAIC, happens on alll the paper cones i run into)`helpsn but you can coat the metal to. Ceramic is particualrily bad in that respect.

In most cases trying to pigeon nhole specific general materials will fail.

You can compare 2 (or more) drivers directly, be very careful with generaliztions.

dave
 
I had good results with polypropylene cones in fullrange drivers using EQ and current driven amp.

If you like DIY I propagate sandwich composite cones especially for fullrange like in this example (diy by me)

I have seen this before. I might try it with one of my cheaper drivers to see what it does.
 
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It would be a magnesium alloy. It is very floppy and very flammable. Ignoring the floopy dome, it would be fairly easy to find yourself playing nloudly and the dome catching fire spetacualliy.


Of the 8 you list there are 3 paper cones. There are thousands and thousands and thousands of paper receipes. Paper from wood, cloth, silk, wool, hemp, manilla (pseudo-hemp), wood itself.

Like the metalcones which are all likley to be alloy, papers are a blend.

Plus, shape, cone profile, mass, much more just talking about the cone. And then you have to consider the other compromises a designer must make.

All this makes for a fairly limited amount of real info.

You might be able to make some generalizations — each with multiple counter examples.

For instance a stiff cone will tend to have ringing issues.

But note: if you take the Alpair 7.3 (Al, mg, + more alloy), vrs the paper cone version A7p. The metal rings a bit, the paper rings more. Coating the paper (AFAIC, happens on alll the paper cones i run into)`helpsn but you can coat the metal to. Ceramic is particualrily bad in that respect.

In most cases trying to pigeon nhole specific general materials will fail.

You can compare 2 (or more) drivers directly, be very careful with generaliztions.

dave
Noted.

On that note: what's are your thoughts on deep VS shallow cones?

My zaph 5" ae very deep for a 5" but, for example, those Textreme 5" are super shallow. And yes, I am asking for a generalization here as well. Which you just told me not to do. I am a rebel by nature
 
To discuss this sensibly, you first need to determine what you want a 'perfect' cone to do.

I'll start off by saying you DON'T want it to be a PERFECT PISTON. This was understood as far back as Kellog & Rice when they invented the moving coil speaker. Alas since then, there has been loadsa liquid BS about perfect pistons. hence da stupidly $$$ ceramic, metal (to some extent) bla bla materials touted as supa dupa but don't sound good.

The first sensible formal investigation was by Arie Kaizer of Philips. He has a couple of AES papers, some Philips Tech. Journal and IIRC, some more recent ones this Millenium. There's also stuff by Jordan who had the right idea but his maths was dodgy.

What you want in a cone speaker is for the radiating area to shrink in a controlled manner. SCAnned Laser Plots show how a good sounding plastic cone shrinks ... and also how a good sounding paper cone shrinks in a very different manner. The 'woven' materials (carbon fibre, kevlar bla bla), because of their weave, don't have the required symmetry for nice controlled breakup. IM not so HO, they always sound blah compared to better materials.

It turns out that Unique Fibrous Material (ie paper) is still one of the best cone materials and is unmatched above a sensitivity of about 90dB/2.83V@1m. Below that, the best cone materials are some filled Polypropylene formulations (which are not on your list). Actually UFM is still excellent below that sensitivity. It's main CON is consistency compared to an engineered plastic.

I've specified at least 2 of these formulations as well as paper mixes and experimental work on metal, Kevlar bla bla cones and Beryllium, Ceramic, Aluminium and Titanium domes (which have somewhat different requirements).

Of course there is more to 'good sounding' cone behaviour than the material and I've done FEA work (confirmed with real life builds) on shape and how they are terminated.