Frequency Response

45hz +-3db? 6db?  What's the SPL at 45hz? 

Maaaaaybe...

The manufacturer specification and the the measured in-room response are different, and the decision to include of subs depends on the latter as well as the individual preference and ambition. 

@erik_squires 

Nice article.  It’s well written and well executed  I appreciate your honesty when you said:

”Lets be honest, these are not typical results.  This happens to be the combination of my speakers, room, listening location and, very importantly, room treatment.”

Back in the real world, DBA is how we do it, you know that. 

1st, measure what you are actually getting in your space.

https://www.amazon.com/gp/buyagain/ref=ppx_yo_dt_b_search_bia?ie=UTF8&ats=eyJjdXN0b21lcklkIjoiQU40QkNTUzc3OExSRiIsImV4cGxpY2l0Q2FuZGlkYXRlcyI6IkIwN1lT%0AOTQ0MkMifQ%3D%3D%0A

get one with threads for a tripod mount, set it up seated ear level at your listening spot. 

measure what you say?

this test cd has 29 individual 1/3 octave bands, 

you can measure as setup, alter the toe-in a bit, move in/out of corners ...

you will definitely learn something.

now compare what the speaker's specs say and what you have been/are getting. you might be surprised how much bass you think you have and how much bass your mic thinks you have.