@gdaddy1,
When you take the 'advice' of a chatbot, you should be somewhat skeptical of the response. Mostly because a bot doesn't know everything, just what it has been fed.
Introducing DSP can introduce time and phase issues, using steep slopes, can introduce the same problems.
These issues have been understood by many speaker manufacturers.
Trying to make a bookshelf speaker perform like a tower speaker, by adding subwoofers is unrealistic. You would be better served by buying a speaker that can perform to the standards you are looking for.
If that isn't in the cards, because of budget. Then just enjoy what you have and save your money. I don't want to p*ss on your dreams, but, speaking as a fellow audiophile with limited means, I think I know what you are trying to do.
I'd be happy to help you with your journey. PM me.
Bob