Am I Better Off With Limited Low Frequency Speaker In A Small Room?

I agree with those who suggested smaller main speakers plus subs.  Acoustic suspension speakers generally control bass better than bass reflex (i.e., ported) speakers.  Also, my experience is that (at least) two subs can be integrated better than one.  If the type of music you enjoy has significant low frequency content then  I would definitely include the subs.

I'm not a fan of subs. There can be a discontinuity in tonality. I have never heard one in a room where I didn't prefer listening to music without it. 

Due respect, you’ve never heard decent and properly dialed-in subs.  When properly integrated you’re not even aware subs are even on much less hearing any tonal discontinuities (sub’s crossover and/or volume was probably set way too high if that’s the case).  When subs are well integrated it’s the exact opposite of your experience — you won’t listen without them.  BTW, subs don’t just provide bass.  They dramatically improve overall imaging and soundstage and greatly enhance the sense of space and detail in a recording, and when you turn the subs off everything just collapses.  And with 40Hz as your lower limit you’re missing out on a ton of the musical experience.  Just my experience FYI.  BTW, don’t take my word for it — order a pair of SVS SB1000 Pros and see/hear for yourself.  They offer a long in-home trial and pay shipping both ways so literally costs you nothing but a little time.  My $0.02 FWIW. 

PS - The Fritz with the Scanspeak sliced paper mid-woofers are outstanding choices in a room like this.

I’ve spent a few months putting together a system in a 121/2x23x10’ room. I added a pair of REL S/812 to a speaker that covered all but the lowest octave. My subs cross over around 25-30hz and volume is set to 1/4 of full volume and my phono cartridge was not liking the bass. I moved everything to seven different locations, but no luck. I’ve got a hardwood floor with a thick pad carpet, but the room is suspended over a two car garage..so lots of issues with bass. So far my solution is bass traps..nine large bass traps, Tiger Maple rack with 3" thick shelves..plus 3" turntable isolation stand with a 108 pound integrated Amp on the bottom shelf. Also, I added a full size low back sofa.

My main speakers are Sabrina X and yes, the subs make a difference.

I listened to my Canton Ref 9K the other day and was surprised by their ability to play bass notes very clearly. I looked at their specs and they are said to hit 25 Hz but I guess that is a few db below neutral. Great stand mounts and could work great in a small room. I will probably add subs later since my room us larger than yours. They also looks like a million dollars in the walnut finish.