I think that if you run your main speakers full range you have to set the sub crossover below the mains. So I think 30Hz is a fair guess for where you would have to cross.
My guess is that the crossover at 50Hz will result in boomy, muddy bass. It's pretty clearly audible if there's too much overlap, and it doesn't sound good.
As I see it you have two choices ... either put a high pass filter on the main speakers to take them to about 60Hz cutoff (I think that ACI, makers of the Titan sub sell passive filters for this purpose). Another filter option is to get an active crossover, but these can be expensive.
The second option is to get a new sub like a REL which can crossover at 30Hz or below. REL goes to 22Hz as its lowest crossover frequency, and I think this is a key reason for REL works so well with so many speakers.
My guess is that the crossover at 50Hz will result in boomy, muddy bass. It's pretty clearly audible if there's too much overlap, and it doesn't sound good.
As I see it you have two choices ... either put a high pass filter on the main speakers to take them to about 60Hz cutoff (I think that ACI, makers of the Titan sub sell passive filters for this purpose). Another filter option is to get an active crossover, but these can be expensive.
The second option is to get a new sub like a REL which can crossover at 30Hz or below. REL goes to 22Hz as its lowest crossover frequency, and I think this is a key reason for REL works so well with so many speakers.