If I understand correctly, you are running both the L&R speakers full range as well as the sub.
Suggest you get a Paradigm x30 active crossover. Put it in your system AFTER the pre-amp. Get another acceptable amp, (a monoblock 1-channel is all you need) and drive the passive sub with that.
You'll be connecting the line-level low freqs off the x30 to the sub amp and the line-level high freqs to your sumo Polaris 310.
This setup passes the low frequencies to the sub and the higher freqs to your Titans. The low end is adjustable and your have 2 or 3 (I forget) choices of your crossover point for feeding the Titans.
The x30 is usually available here used for $125 and the amp choice for the sub is up to you.
Good luck and hope this helps!
Suggest you get a Paradigm x30 active crossover. Put it in your system AFTER the pre-amp. Get another acceptable amp, (a monoblock 1-channel is all you need) and drive the passive sub with that.
You'll be connecting the line-level low freqs off the x30 to the sub amp and the line-level high freqs to your sumo Polaris 310.
This setup passes the low frequencies to the sub and the higher freqs to your Titans. The low end is adjustable and your have 2 or 3 (I forget) choices of your crossover point for feeding the Titans.
The x30 is usually available here used for $125 and the amp choice for the sub is up to you.
Good luck and hope this helps!