Why I'm not adding a sub to my 2-way monitors for music

Adding a small sub to augment small monitors was one of my better decisions. 

2 major improvements that have left me scratching my head

* I sold 2 SVS powered subs: purchased new 10+ years ago, never designed to compliment a hi-end system, but I thought I needed them as my room is ~ 21 x 35 x 12 (open beam ceiling) with lots of glass front and rear, plus a tile floor, when I had Magnapan 3.5Rs

Also, I had my Emerald Physics 3.4s (2 way) 12" concentric drivers with 1" polyester tweeters sitting on Harbor Freight dollys so I could maneuver them easily, but once I got rid of the subs and moved the 3.4s some 2ft back, wrangling them off the dollys, and onto one toe (OUCH), then placed 4 each loaded Nobsound springs under them, the music became amazingly life-like. My LSA Voyager 350 has a lot more lower mids and bass then I was aware of. In most rooms I doubt anyone would need more speaker than these. They can be found used for under $1000!

Due to my room and cabinet I am restricted to using bookshelf speakers with 8 inch drivers. 

Adding a sub makes a more full sound. You also muddy the midrange if you are asking your speakers to play a 50hz tone along with a 1000hz tone 

Nothing against those that choose to use a sub, to each their own. To me, it is over kill and not necessary. Most music contains nothing below say 40 hz...most speakers with say a 40 hz rating actually go significantly lower when interacting with the room. Lastly, you will never get the timbre to match the 2 channel speakers. To me, you are ruining the sound of a well designed 2 channel speaker.

Uh, @audioguy85, a statement like this indicates someone who’s never experienced a sub properly set up and hence is focusing on the wrong things.  You have no idea what you’re talking about.  Wilson Audio uses subs with their Alexandrias, which go gobs lower than your speakers could ever hope to.  What do you think you know that they don’t?  Ugh. 

@soix I think @audioguy85 is referring to adding separate sub-woofers to speakers, but not to those that are already part of the speaker system. Not only Wilson, but Vandersteens Quatro have built-in sub-woofers. Those are fine. He is questioning the wisdom of adding sub-woofers by end-users which are not part of the speaker manufacturers recommendation. This is just a trial-and-error procedure hoping to get something in addition to what main speakers deliver.