What creates the effortlessness in sound reproduction?


Hello, 
I have a chance to listen some speakers in the last 10 years. I notice that there are 2 speakers which produced sound 'effortlessly', even at low or high volume levels (I never tried max levels on them since they are not mine). With this effortlessness, listening to music is very relaxing. 

I wonder what makes the effortlessness in these speakers? 

Please shed some light on this. 

Thank you. 
Huy
Ag insider logo xs@2xquanghuy147
There are about six or eight critical system factors that result in the "effortless" sound of speakers. It's a holistic system result, not just the speakers.   
effortless can mean different things to people. The only way to find out the answer is to become involved in speaker design. There are no shortcuts. 

The electronics and the overall “system engineering.” Up to and including the speakers.