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Discussion Starter #1
Hi,

I've noticed that different subwoofers use different cone materials. Common materials seem to be plastic, aluminum and paper.

So I just wonder what the pros and cons are of the various cone materials? And does it depend on element size, amplifier, price, or similar?

Clearly there is not one material that is best in all aspects, or everyone would use that. So does anyone know? :confused:
 

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http://www.data-bass.com/data?page=knowhow&type=1 see #6 re: sound quality

In general you want the cone to be weightless and infinitely rigid. Since this is impossible you are looking for a balance of weight and rigidity so the best material varies depending on other mechanical and electrical attributes of the driver.

Also many times the varied materials and "looks" are simply for aesthetic purposes.

Bottom line don't use cone material as a buying decision, great subs can be made with "standard" pulp cones.
 

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Discussion Starter #4
Ok, so what negative effect will it have if one cone is heavier than another?

And what positive effects will it have if it is more rigid?

Also is the order or heaviness & rigidness as follows:

Aluminum > Plastic > Paper
 

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There are so many factors that make a good or bad subwoofer that the cone material should be the least of the concerns. Two companies could make subwoofers with identical cone materials but one could use a small spider and undersized motor system or have a more flexible surround material. If the concern is about sound quality, I think it's a moot point at the frequencies that a true subwoofer has to work in. I guess I don't really understand what difference it makes.
 

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Ok, so what negative effect will it have if one cone is heavier than another?

And what positive effects will it have if it is more rigid?

Also is the order or heaviness & rigidness as follows:

Aluminum > Plastic > Paper
Doubling the weight of the driver makes it 6 dB less efficient.

Also, the more the cone weighs the energy it stores-- causing ringing, more distortion from breakup modes, and all sorts of things that a speaker designer needs to pay attention to and try to compensate for, commonly by tweaking the crossover design. More rigid materials give a flatter, more linear response and hopefully have less distortion or at least distort mostly in frequencies above human audibility.

As for which materials, your ordering is generally right, but better craftmanship and care with the driver design matters as much (if not more) than paper vs polypropelene. A good paper cone can have great sound, although they are perhaps more sensitive to high humidity and moisture than PP or metal.

Here's a random hit from Google that seems reasonable:

http://www.audioholics.com/loudspeaker-design/loudspeaker-drivers/diaphragm-material
 

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Ok, so what negative effect will it have if one cone is heavier than another?

And what positive effects will it have if it is more rigid?

Also is the order or heaviness & rigidness as follows:

Aluminum > Plastic > Paper

More weight equals reduced efficiency and potentially worse transient response but BL will play a large (or larger) part here.

The more rigid the closer to acting like a perfect piston.

It would help to know your underlying question, or what it is you are trying to determine.

The important thing to consider there is no best, the cone material is just one ingredient in a total system. For every advantage say dry carbon fiber has over aluminum it will have disadvantages as well.
 

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Would you be worried about paper cones in humid climates but that are indoors?
Humidity does effect the Mms and some other characteristics of a pulp coned speaker, even ones with treated pulp cones, though to a lesser degree. I have seen more discussion of this from guitar players than "audiophiles", partially since they often play in varied conditions.

In a home with a properly sized HVAC system (too large a system causes worse humidity swings than a proper or even undersized system) the difference will be a non-issue in a subwoofer especially.

In the end subwoofer cone material is far less an issue in SQ than it is with drivers that produce higher frequencies.
 

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My A/C is opposite situation - upstairs unit runs long cycles which is where the subwoofer is located (bigger downstairs unit runs shorter cycles.)
We really are into minutia here, especially with regard to subwoofers (I don't mean that in a pejorative way). I can't imagine being able to hear a difference in most situations.
 

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Cone material alone means nothing; there are other parameters in speaker design (like some have suggested) that collectively contribute to overall performance difference, if any.
More of profit maximizing tricks for the manufacturers than anything else that is objectively proven and/or desired in real world application.
 

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Discussion Starter #13 (Edited)
Well, e.g. Rythmik seems to think cone material matters.

They for example have two versions of the same subwoofer, one with aluminum cone (F12) and one with paper cone (F12G). They are identical except for that, and cost the same too.

Rythmik says about the:
F12: "Compact aluminum cone sealed subwoofer. Great output for its size. Ideal for combined HT/music systems. Recommended for speakers with 5” woofers or larger."
F12G: "Same size as F12, but with a paper cone. Great frequency response up to 120 Hhz. When used with smaller front speakers, a stereo pair is recommended."

Also, the frequency response differs:

F12 with AVR/12 low pass filter:


F12 with LFE low pass filter:


F12G:


So clearly the cone material affects the properties of the subwoofer.

What I wonder is what properties and pros/cons there are of different cone materials in general. We've already heard some opinions on that in the posts above.
 

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Untreated paper deteriorates over time. This has been a problem for countless antique speakers over the years. Modern paper cones are usually treated.

Some materials have resonances, but this is likely more apt to affect full range speakers than subwoofers.
 
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