Can recommend some non-fatigue SMALL bookshelf for near-field listening?

@millercarbon will be along any minute recommending Tekton Moabs 🤣

Thanks all, I just checked a bit re the recommendations. Adding a subwoofer is not an option at this moment. Specifically, a pair that can go down towards sub 50 Hz would be ideal. The 6-inch ones are just too big (typically >30 cm depth). 

BTW: my source is PC --> t+a dac, indeed I am using DSP rolling off from  1k - 20k ( -3db -- - 5db). 607s do not sound fatigue that much, but  I have no clue at what cost. .....  

On the lower end of the cost spectrum you might check out a used pair of Monitor Audio Bronze 2 speakers, Generation 5.  They just barely fit your depth requirement, have a 6.5 inch woofer and are front ported so you can place against a wall, although in my room they sound better 6 inches off the back wall. I have them placed on 8" stands on my desk. The Bronze 2 specs claim a frequency response of 42Hz - 30KHz. 

I find these easy to listen to for hours at reasonable volume.

These replaced a set of KEF 100's that were way too bright in a nearfield situation.

Take a look at Alta audio.

+1 Elac Unify Reference.