As some have already pointed out. Bass is an issue. You need to use the equivalent of a "loudness" button at low levels or you will lose the bass response due to reduced hearing sensitivity.
If you refuse to have any tone controls whatsoever (often an audiophile affliction) then you need to find a speaker with warm resonant harmonic distortion in the bass. You could also look for a tube amplifier or something with high output impedance that will boost the speaker at the woofer resonance point (more bass) and increase harmonic distortion (you can create this by overdriving slightly a tube amp without sounding too loud. SS amps can't do this as they sound awful when overdriven).
Remember that sounds seem louder or better defined if they are rich in harmonics...perceptively this means that the tone or note sounds "fuller". You lose some accuracy in terms of true timbre of the instruments but you gain in having a system that you can enjoy at quite low levels without disturbing others.
If you refuse to have any tone controls whatsoever (often an audiophile affliction) then you need to find a speaker with warm resonant harmonic distortion in the bass. You could also look for a tube amplifier or something with high output impedance that will boost the speaker at the woofer resonance point (more bass) and increase harmonic distortion (you can create this by overdriving slightly a tube amp without sounding too loud. SS amps can't do this as they sound awful when overdriven).
Remember that sounds seem louder or better defined if they are rich in harmonics...perceptively this means that the tone or note sounds "fuller". You lose some accuracy in terms of true timbre of the instruments but you gain in having a system that you can enjoy at quite low levels without disturbing others.