There are dozens and dozens of different types of materials used in the production of speaker cones. The material of the speaker cone affects the sound quality, durability, and power capacity of the unit.
The ideal cone of a speaker is lightweight, which contributes to the responsiveness of the signal. During operation, the speaker moves in and out to create sound waves; therefore, the lighter the cone, the faster it will respond to incoming signals.
Cone stiffness is also an important factor in speaker cone material. If a cone is not rigid, it will vibrate and introduce unwanted frequencies into the listening environment.
Paper Cones/Treated Paper :
These cones can produce excellent sound, but for how long? Traditional paper cones for speakers are frowned upon in the world of car audio. The car audio environment inherently features a lot of humidity and temperature variations. These two factors, over time, wreak havoc on a paper cone, which eventually deteriorates, rendering the speaker useless. Fortunately, speaker manufacturers have developed synthetic materials to combat these problems.
Polypropylene Cones: A step up from paper and popular cones in the car audio world, these cones are rigid and extremely resistant to moisture.
Kevlar Cones: Yes, this is the same material used in bulletproof vests. Extremely light, very strong, and extremely stiff, these are the three characteristics you want in a speaker cone. In addition, this material has excellent damping capabilities, which helps control unwanted vibrations. Of course, Kevlar isn’t the only exotic material that has these properties; Other materials, such as fiberglass, aluminum, and flax fiber, have also proven their worth in car audio. As for the best material for the cone, it depends on your personal taste.