If your RM30's are biampable between the mids and bass, would this work: Two pair of outputs from the preamp, one to the amp powering the mids up with the passive xovers in the RM30's doing the filtering, the 2nd pair of outs to an EQ. Two pair of outs from the EQ, one to the amp for the bass in the RM30's, with the passive xovers in the speaks giving a low pass. the second pair of outs from the EQ to the sub with the subs xover giving a lowpass filling in under the RM30's. Here the EQ will be active on the bass from the RM30's and the subswith only one EQ. I don't know how high the bass drivers on you speakers go before the passive xovers come in, but if it's higher than 200hz, the R-DES might not be the best choice.
This makes sense in my head, not sure if it does on paper.
Ryan
