Hi Bill. No, the only paper cone is the 12. The reason for that is that it is more of a GR Research product than a Rythmik one. The two companies and their owners have a unique working relationship. Brian was already offering the Rythmik products, and that’s what drew Danny to him, specifically with the intent of collaborating on Danny’s idea for the OB/Dipole sub. The sub is really Danny’s baby, and he prefers paper cones. The 12" aluminum cone version is all Brian’s, the paper version being exactly the same (with one exception---read on) but for the cone, which Danny finalized the parameters on. One can buy an F12 with either the paper or aluminum cone, sealed only.
There are two versions of the 12" paper cone woofer: the first is for use in a sealed or ported "normal" sub. The second is one whose parameters have been optimized for Open Baffle or Infinite Baffle use. You cannot use a regular woofer in those two applications, nor an OB/IB woofer sealed or ported. The free air resonant characteristics and other specs are not the same, and the two woofers cannot be used interchangeably.