My, my, there's a lot of opinions out there. Thank goodness for that! I suppose a few hornets have been riled up by my comment of not rolling off the bottom of your main loudspeaker to accommodate the sub. I suppose that needs a little more explanation.
First, let me repeat an oft mentioned 'Paul's Rule'. The goal of any loudspeaker system, or for that matter any music system, is to disappear. There's no higher compliment given than when people sit in Music Room One and ask where the sound is coming from because, 'surely it's not coming from those big speakers'. Those 'big speakers' disappear and that's the whole point. Same with a subwoofer. The greatest compliment to any subwoofer installation is that it is invisible.
Think of food. The individual ingredients should be invisible if they were prepared properly. You don't want to say to a chef 'I can sure taste that basil'.
So the idea of a subwoofer is to augment the performance of the main speaker and then do so in a way that never draws attention to itself.
Now, on to the main topic, to roll off the bottom of the main speakers or not. I say NOT.
Why would you want to roll off the bass from the main speakers? Because of an effect known as Doppler distortion. Simple to understand, Doppler distortion describes that property of an object, like a speaker driver, to do two (or more) things at once. I know ... that's not entirely accurate ... but it'll do. If a slow moving woofer is also making higher frequencies at the same time as it's slowly woofing, then those higher frequencies are being modulated by the lower frequencies causing a type of 'muddiness' or 'muddledness' to the sound. Better to have the woofs woofing and the tweets tweeting, never the two to meet. That's the reasoning behind removing the requirements for bass from the woofer and assigning it to the subwoofer.
But here's the thing. The methods used to remove that bass from the main speaker (yet another crossover filter) add more trouble than they remove. That's my thought on the matter.
You know what? Your main speaker was designed, I am assuming, from someone competent enough to make it all work. Leave it alone. Augmenting it with a sub is smart. Changing its functionality is not.
Thank goodness I don't have an opinion on the matter.