Viridian...Your question, "Where, as you assert, did I say that sounds 10 to 20db below what is audible are things that you should "care" about?" is one that I cannot answer because the posting has been (conveniently) deleted.
Thanks for the link. Interesting, but I have seen it before.
In my multichannel system (5 channels contributing noise) I never hear noise with digital sources. With LPs, quiet passages almost always have enough audible noise to bother me. (Perhaps I am more sensitive to this than you are). My spectrum analyser clearly shows why this is so.
I have no special record cleaning equipment, and I am talking about ordinary LPs: not special audiophile editions. While the noise floor of the LP system is pretty well defined by the technology, the maximum signal can be anything that the recording engineer thinks his customers' cartridges can track. Most LPs intended for the general public have been compressed and peak-limited so that Joe sixpack can play them.
By the way, I think that dynamic range is not the most important parameter. Sometimes I find that quiet passages, even without noise, are difficult to hear unless the volume is cranked up so much that the loud passages are ear-splitting. Too much of a good thing.
