Speakers sound brighter at evening / night?

I know it's a lot quieter at night at my house.  I can hear and feel the train which is about 1500 yard at the closest point. At night I can really hear it if I listen.. I figured it was all the background noise that wasn't there in the day..

It sure makes for a quieter listening session, if the gear is warmed up and it's after 1:00 until about 3:30. My oh My.  The WiFi is shut down from 0001 to 0600, along with a few other things, refer (doesn't come on), fan motors, all the crap.. LOT cleaner grid...

Between the two...a lot better, cleaner SQ

Regards

Yep, there's usually less vibrations and less residual background noise.

You might also feel more relaxed and able to focus better on the sound.

For many years I used to feel that my car drove much quieter and smoother at night. It was like, wow I never realised what a good car this was. 

Next morning, it was back to being plain Cinderella again.

Do not have this problem however were i live we have or own power plant.

Things sound better at night, not brighter.  Brighter ≠ better.

It just occurred to me how we could perhaps test this idea. I see a lot of youtube videos of people's high end systems playing. You get to hear their system, sort of. It's obviously a  flawed method, but it can tell you some important things like bass response and overall room sound. If the music sounds clean and natural in a recording like that you know that the system has to be working pretty darn well. With that in mind, might it be possible to catch the difference in sound by recording in the daytime and then with everything set exactly the same record again at night? Any major changes in the sound should be picked up by the recordings.