Why are you considering changing your subwoofer? What don't you like about your current set-up?
The old SVS SB4000, recently discontinued, and possibly its replacement the SB5000 can be low passed as high as 200 Hz.
Sub for 2 Channels
i am considering 2 subs to replace 2 avantgarde 225 subs on the Duo. The mid range rolls off at 170hz. Currently i set up the sub at 170hz where the mid cuts off.
i look at Rel carbon and see its crossover setting range is from 20-100hz. My question is that does Rel Carbon Special fit my speakers? any opinion and advise are greatly appreciated.