All of the above are good answers and yes it is a buzz word used by the manufacturers.
I'll give you the simple answer as the term black is used in my work in the film/video biz.
We all know the term "fade to black"... there is video black and audio black. Both mean no picture or sound, no noise, no distortion. The purest black can be measured on a scope as zero black. (like a flat line).
In hifi I would say black is a signal with no noise, hiss, colouration. The cables would accurately present the music from the source to the speakers.
I'll give you the simple answer as the term black is used in my work in the film/video biz.
We all know the term "fade to black"... there is video black and audio black. Both mean no picture or sound, no noise, no distortion. The purest black can be measured on a scope as zero black. (like a flat line).
In hifi I would say black is a signal with no noise, hiss, colouration. The cables would accurately present the music from the source to the speakers.