speaker cone designs

i've seen several kinds of speaker (mainly woofer or subwoofer) cone designs ranging from JL's tradiaional smooth cave cone, the more tradiaional cone with a simple dust cap, to alpine's new cone with a metal centerpiece that's not even part of the cone looks like s spike) : can anyone explain the differences between these cones and they're effects on the sound reproduction?you can never have too much of a good thing

Nothing. In a sub application, it is possible the dustcap COULD add some rigidity, which MAY or MAY NOT affect the audible sound quality (as opposed to the distortion, which is not generally audible until very high percentages are reached - around 10%). Generally speaking though, the dustcap is to prevent foreign objects from entering the voice coil gap, and quickly destroying the voice coil.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

For subwoofers, it makes no difference as long as it can stay pistonic and you can have the moving mass required for the design goals.  For upper frequency drivers it has a large impact on the sound.  The "spike" is most likely a phase plug.

... and there is no real reason for a phase plug in a subwoofer other than a possible "bling" factor!Support the12volt.com