Better sound at night?

[Axel]

Late night is also a fine when the body /brain relaxes more.

Now you hit the other side of the coin!    Sorry for digging little deeper... Our autonomic nervous system consists of 2 aspects, sympathetic (activity) and parasympathetic (rest). It´s easy to measure these parameters with so called Heart Rate Variability (HRV). Balance in HRV is a sign of health and coherence. Noticed that it sometimes takes 3-4 tracks before I enter a kind of relaxed coherent listening state. So once I tried to meditate for a short while before the music session and experienced directly a state of coherence.

There is also the possibility that at night, when it's darker the senses shift more from eyesight to hearing, and thus have an effect on the SQ, to your ears...

I'd never thought about it that way, but it makes perfect sense. Like Jonas says, the music seems to immerse us more when we shut our eyes.