Regarding all those (ditto related) posts, I need to point out that I asked about separate frequency and damping controls not because I wanted to buy a premium Rythmik sub or upgraded amp (if even possible) nor because I wasn't satisfied with the single combined control on my LV12R.
I asked a technical question because I was curious about how damping and frequency response are related.
So, getting replies that either told me to get 1 or 2 FV15HPs or to not worry about such things and just enjoy my LV12R were to me not helpful to me as the only reason I asked the question was for a clear, direct, straightforward answer.
And I greatly thank those who did directly answer it, including a few Rythmik sub owners and of course, Brian.
However, as a future (polite) suggestion, if I ask a technical or academic question, I'm asking because I want to know the exact (or close enough answer), not because I'm looking to make a purchase/upgrade or because I'm dissatisfied with what I presently have. Hope this clarifies what I'm trying to achieve when I ask such questions.
And I don't consider it over thinking things... I just have a very technical, analytical mind.