A common opinion is that NS10s are so bad, that if you can make a song sound good on them, then it will sound good on anything. While there are elements of truth to this, it goes a bit deeper than that. NS10s are known to reveal problem areas in mixes with almost brutal honesty, the kind you’d only heard from a drunk friend after midnight. It’s said that they can act as a magnifying glass for mistakes, which has allowed audio engineers to go over problem areas with a fine-toothed comb.
More specifically, this magnifying glass sits in the mid-range to upper-midrange, which is arguably one of the most important areas to work on, especially for developing detail and presence in a mix. High end and low-end frequency reproduction tend to vary a lot depending on speakers.
You hear manufacturers all the time talking about deep immersive bass and crystal-clear highs, it’s what makes something sound big. However, the midrange is much less variable between speakers, from monitors and all the way down to portable speakers which are just about all mids.
Nailing the mids is important, it’s where vocals, guitars, pianos, the snare, as well as kick attack and character and clarity of the bass all sit. Needless to say, it can be a busy place, so getting it all sorted out first with the NS10, means that it will translate well just about anywhere.