Most impactful for playing soft

     Here's why, at lower SPLs, your system's lower freqs sound weak:

https://www.teachmeaudio.com/recording/sound-reproduction/fletcher-munson-curves

     Most older receivers had a 'LOUDNESS' function that boosted lows and highs to compensate for the typical ear's curve at lower volume levels.

              http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/eqloud.html

@milog -

     One can preprogram a number of freq response ("loudness") curves, with one of these devices, for those special times:

       https://www.minidsp.com/applications/dsp-basics/system-equalization

@secretguy -  

         A receiver with a loudness control :)

                                 OR: DSP

      (with which to program a little boost, at times*)

  But: let's not deprive the fact resistant of their beloved chasing-of-the-tail (with *the answer).

https://www.extron.com/article/loudnesscontrol_ts#:~:text=The%20loudness%20control%20is%20simply,treble%20appear%20to%20be%20lacking.