Lowering the noise floor

I am coming to the conclusion that success in home audio reproduction is largely about lowering the noise floor. There are so many different types of “noise”, from so many different sources, that we only really “hear” by their absence.

Those components, cables, accessories and tweaks that SUCCEED at lowering the noise floor, can, and do, dramatically increase sound quality. Sometimes the type of “noise” dealt with is controversial, or not (yet) widely recognized as being a problem. Sometimes the explanation of how a product works is dubious. Sometimes the way it is marketed reeks of “snake oil”. Sometimes the reviews singing its praises go over the top. While these things will certainly put off some prospective purchasers, they do not negate the audible results that are there for anyone open to hearing them.
However, before you can benefit from a lower noise floor in your gear, you will need to lower the background noise in the listening environment. I just measured mine at about 35 dB on a Sunday afternoon, and that is low. When the house was designed we did a lot to achieve this. At that stage it is quite easy and cheap, unlike afterwards:
1 a quiet location, in so far as such a thing exists in a densely populated country like mine, and in a (sub)urban environment.
2 special window glass
3 muffled ventilation openings
4 quiet floor heating system.
5 quiet mechanical ventilation system that is only turned on when needed.
6 quiet water pipe layout.
7 quiet kitchen machinery like refrigerator and dishwasher.

It all makes a difference, but even then it is not concert hall quiet, and since maximum sound levels cannot be as high as in a concert hall, the dynamic range is inevitably smaller than in that concert hall.
I look at this topic in 3 different ways:
  • background noise
  • signal noise
  • environmental noise
Different products will affect the first two aspects of noise floor.
Sure but if for whatever reason the noise floor in your room is high, it will mask any noise from your electronics. Given the noise levels involved, this is not just a theoretical problem.