I wouldn’t recommend upgrading nor installing different components to the crossover, it will change this drastically, I would download a software called REW on your computer and you can use that to see if your your speaker are running optimal. You might have to fine tune them on your receiver depending on your software.
Also I notice when you set your towers to large and keep the subwoofers on it makes big difference in the sound as well, I tried small/large in comparison and if you want more bass output since the 1723 THX towers have two 9’ drivers, set them to full range. Let your ears be the judge, also if you’re just hooking the speakers up to just the receiver I wouldn’t recommend that either because you’ll notice a lot of distortion and clipping. If you are running them on a separate amp then thats awesome. Then you can set the speakers to small/large and notice the difference in the sound quality.