Low level resolution is combination of the speakers and the amplification. IME, some amplifiers are better at delivering a balanced drive across the spectrum, regardless of the amount of gain, versus others that require more juice. IOW, some amps require you to pour on the power for the sound to properly coelesce. Whereas your Klipsh's are pretty efficient, I don't know if efficiency has any correlation to perceived low level resolution. You might try borrowing some other amps/integrateds and see if you get better results. I know I did.

Hope this helps.