Schiz, welcome. The first point is that the HK isn't "warm"; it has a flat response and doesn't add a sonic coloration. Likewise, the Axioms aren't "bright" and the resulting sound won't be unless the program material has that character. Wherever you heard that, it was simply a repetition of audio mythologies which have no factual support.
In a relatively small room the M22s should serve you very well on most material even when used without a sub at first. The effect of room reinforcement in my room with the M22s was to give quite strong response down to about 50Hz and much weaker, but still usable, response at 40Hz. This is satisfactory for most types of music(pipe organ excluded), although for best results with the LFE that occasionally is present during movies the addition of a sub will be highly desirable.
