System sounds better at night?

I have noticed that my system sounds MUCH better at night, after about 10pm than at any other time of day. It is clearer, more open and transparent, with a blacker background. Another audiophile told me that this is not real, it's just that there is less noise in the household at night. I disagree in that what I hear (or don't hear) is not simply due to less ambient noise but rather cleaner sound. Will power line conditioners simulate these effects during the day? Has anyone else noticed this and what is the most effective way to get better sound during the daytime? Serious responses only, please.
Tell your buddy that someone is "smokin' somethin'" but it's not you. This is a common occurance and you are not alone in your findings. My systems typically sounds noticeably better after about 1 or 2 in the morning. Soundstage becomes far more vivid and detailed, there is a "haze" or "grunge" that is removed, everything becomes more lucid, etc.... While i wish that i could achieve these results all the time, it is probably not achievable unless one has their own generator system to plug into or the capability of being able to run everything off batteries. Sean
check out steve deckert's musings on his site great stuff, some speculative, about late night listening.
it has to do with fewer draws on the power grid from the general public at night; more relaxed state of mind at night?; less ambient light means more concentration on sounds instead of sights; different electrical characteristics while insulated from the sun...all these things add up!
My system goes into this super quiet hyper-drive mode about 11 PM every night-- it's a well known phenomenon among audiophiles as Sean notes above.

As to achieving this quality during the day; putting in a dedicated AC system, ground system, high quality power cords, and getting rid of my power conditioner helped a lot. But even then, the 11 PM effect became even more pronounced. Cheers. Craig.
I tell the truth. I now have most of the atributes from this condition with my preamp and CD player pluged into a PS audio Power Plant 300, and Sonic Horizons Skyline A/C power cords, and dedicated lines. This is not an ad. I paid for it all. But I live in power ravaged Southern Calif. with all kinds of industrial pollution. I still get a more refined musical experiance at night. But I also get a very much improved sound all day. Maybe it is just that I am less than 5 miles from Disneyland and all that happiness makes the the Power Plant sound better.
This might help?
If the humidity where you live is 70% or above, your sound
system will sound dead & lifeless.the highs will bounce off
the airborne microscopic water particles & render the sound lifeless.this is one of the main reasons people love & hate their audio gear.Adding a dehumidifier in your audio room will make your system sound system sounds best in the evenings when the humidity is usually lesson in audio technology!
Not only do AC lines have lower demands placed upon them, much of what is heard in sonic improvements at night is due to reduced activity from traffic, construction, etc.The low frequency waves generated are extremely powerful and disruptive and can travel dozens of miles without dissipating.

MP your idea about humidity goes against the jist of the other postings. Humidity goes up at night as the temperature falls closer to the dew point. Everyone is saying there systems improve (at night with higher relative humidities) so a dehumidifier would go the other way. If anything you need to add a humidifier. Don't think so....
This was interesting to read as I noticed this in years past and just chalked it up to less distractions. My brother told me he noticed this also not long ago. Now I read there may be some truth to it!!!
My system alway's sound's better to me at 3:00 or 4:00am, too think I thought it was the case of beer I drank and all the women that were coming over from the bar! Well that still might be some of it!
Mine also sounds better at night. At night people are in bed sleeping so you have fewer electricity poluting things on line. I found that as I go around turning things off for the night my system gets quieter.

Your neighbors polute your electricity. Things like fluorescent lights, TVs, dimmer swithches. These things and many more put garbage in the electrical system which shows up in the background of your system.