Which Component Has the Greatest Affect on Low-Level Listening


I'm looking to get out of HT 5.1 and go strictly to 2 ch.  I generally have music playing all day, often just sitting done to listen to certain tracks.  

I've read that "some" speakers don't sound "good" until high listening level, and also an integrated such the Luxman 505 don't sound good at low levels (is that the reason they include loudness?).

Which component, the amp or speaker, has the greatest impact on low level listening quality?
bgm1911
Start with a very low noise room.  A rule of thumb is that your ambient noise level should be at least half of your average music level.  It's hard to get below 35dB ambient.
If I were to name a single component, I’d have to agree with yyzsantabarbara that a very well executed line preamp with attention paid to stable linear gain attenuation will have the most dramatic impact of fullness at ALL playback levels. 
Tone controls on the preamp to compensate for lower volumes. Took me years to realize this as for 30 years my equipment had no tone control.
A full range full frequency response speaker will have the most effect on low level listening. Also a full sounding amplifier will help at low levels.
No component, except one that includes loudness or tone controls.

Speaker response changes a bit with volume, but any competent speaker will not change even remotely enough to compensate for how much the response of your ear changes with volume.  If your amplifier has high distortion at low volume, you could loose some detail at low volume. Could happen with a pre, but unlikely.

It's your ears/brain that are changing and they are changing by a large amount. Only way to compensate is to change the response of your system.   This is one of the problems in audio. Different listening levels all present a much different balance of frequencies.

https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.kmuw.org%2Fpost%2Floudness-and-fletcher-mu...