“Black background” — What really contributes to this phenomenon?

practikl wrote:  “And after getting a black background you just found out that your new noise floor is your tinnitus...”

I literally laughed out loud as this has been my experience!  I frequently work in an environment that has multiple (40ish) video recorders in a huge racks that all have fans going within them.  Then there’s the noise generated by the robust heating and (mostly) cooling systems.  Toss in a TV and you’ve got the perfect recipe for tinnitus, which I have!

When I listen, I do from 11 pm til 3-4 am. Power is cleaner, and sounds better.

 Myself as also mentioned, lights off or lights on dim and jam out.

I’ve found you have to filter EMI/RFI from as  many physical connections into your system as you can to achieve the true experience of the recording. Mains supply is obvious and for those who stream from subscription services or locally stored FLAC, the Ethernet cable is another delivery system for it. Filter out RFI from your Ethernet for happy days.

Miller's whining on about springs again.   Boing boing.
Just the wrong way to go.  Equipment shouldn't be allowed to oscillate.
Particularly speakers, springs lead to fuzzy unfocussed sound. Blowing in the wind.
Even TT designers have mostly moved from spring suspension to mass loading in the last 10-15 years.
And the more mass the better.