which polk subwoofer compare to the rm6900 sub?

[Polkyyy]

anyone know which of the polk model is/also the same as the subwoofer that can be found with the rm6900 system?

[Dennis Gardner]

None of the "system" subs are regular offerings as a separate subwoofer that I can find. They are all designed specifically for each system. Of course, any of Polk's powered subwoofers will intergrate with most any speaker since the sub frequencies don't have real tonal signature differences.

What did you have in mind?