What do you have today? I suggest you put your system photos under your user ID. That will give us something to work with.
I have have owned 4 B&W 800 subwoofers, two for my home theater and two for my two channel audio. At some point I upgraded my speakers and got rid of my subs… a great move. Better coherency… overall the sound took a giant leap up. But, it depends. What is your system?