The DLS r6 may go to 30hz on paper, but at what db? Normal mainline manufacturers will cut off the freq response spec's when the speaker dips below -3db. I doubt you will hear the r6 at 30 hz and would be a waste of amplification power. You have to consider your subs real freq response and what freq you will crossover at. I would crossover the r6 at around 80-100hz if you have your sub rolling off around there. I like steep slopes(24db) when crossing over. Remember not to overthink the crossover points and go with what sounds good to your ears.
