We've likely all experienced the sensation of a blacker background. Perhaps it's a new cable or a software update that did the trick. Or maybe a power conditioner or regenerator that removed a layer of noise. Whatever the cause, when there's a deeper blackness we hear it.
Or do we?
In a digital audio system, typical background noise levels are very low—well below the threshold of audibility. When we place our ear close to the tweeter we hear some amount of hiss from the analog chain of amps and preamp (or DAC). In a quiet system that small amount of tweeter noise isn't typically audible at our listening position. So, even if we made a change to the system that lowered the tiny amount of noise broadcasting out our tweeter, it's unlikely we'd be able to hear less of it.
So, what gives?
My guess is that when we hear a deeper blackness it's because the noise we're lowering is part of the softest passages of music. In other words, it's embedded or riding on the music. We are hearing the lack of that noise piggybacked on the music.
My logic is simple. When the music's not playing there's zero difference I can hear in noise levels. It's only when the music plays that I notice these deeper velvet moments. Thus, it must have something to do with unwanted energy riding atop the music in the same way we sometimes hear glare and tizz.
It's little more than an observation, but I'd love to hear your thoughts.
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