What is most important factor in digital audio playback quality?

[barrows]

Speakers have more problems than any other aspect of a playback system.  Different speakers sound more different from each other than any other aspect of the playback system.

For #3, the recording chain, including choices made in mixing and mastering, are the most important factor(s).

On 6/27/2019 at 4:30 PM, mansr said:

A DAC is both analogue and digital.

Yes, and the analog section of a DAC is often the most important factor.

[barrows]

22 minutes ago, Seraph said:

I almost exclusively stream my music, so my preference for digital is a given. I do have a few GB of red book rips on my NAS, mainly music I grew up with. In my opinion the space, the room has the greatest effect on sound quality and feel. It's hard to make any equipment sound good in a wrong sized space with a lot of reflective surfaces.

What really bothers me today in streaming is the way most of the available music is compressed. Everything, at least new releases, is stepped on way too hard.

Sometimes I think the emphasis placed by many on the room on these forums is in error.  But, that is because my room is not really bad, in fact, for a domestic space, my room is really pretty good.  I get a reasonably flat RTA without much trouble here, and I do not really have parallel sidewalls to contend with, or any back wall problems.  Some rooms are horrendous, and virtually impossible to tame, even with DSP (square rooms particularly).  So I think the importance of the room is entirely dependent on the specific situation: not everyone has this problem, but if one does, i do agree that this problem can be very significant.

[barrows]

1 minute ago, Seraph said:

We live in a loft apartment, basically a converted attic. While the apartment is beautiful with its high ceilings and a spiral staircase, there are a lot of angled surfaces which makes it hard to predict good speaker and sub-woofer placement. Room treatment is a compromise as there is a balance between efficiency and married life. When asked I usually prefer larger decorative textile pieces of art if the question comes up. Though I think shes on to me.
There is of course DRC but I prefer to keep the chain from source to speaker as simple as I can. I might do some experimentation when I find the time for it.
 

Actually, to me, the room you are describing sounds like it may be better than most, normal, rectangular rooms (or much worse, square).  The one thing I wish I had was a higher ceiling (mine is normal 8').  I find a bunch of angled surfaces to be more desirable than a typical parallel wall configuration, as long as one has some freedom in where to place the listening position.

As all my playback is via computer digital source files, adding DRC without any further complexity in terms of hardware would not be difficult, but i just do not find any need for such here.  I find that through speaker placement and sub controls, I can get to what I am after, but I live alone (my GF lives here sometimes, she is on the road  a lot, and has a place of her own in FL) so i have a lot of flexibility in placement and set up!