05-29-13: Rsimms
Neither. Warm can sound muddy and neutral can sound weak and thin.
05-29-13: Peterayer
On a good recording, if the performance sounds "accurate and natural", I find it usually means that the system has a "neutral" tonal balance, that is, it does not emphasize one frequency over another.
You see....that is the problem with the word neutral, it is often misused. In this case, Peterayer has used the word neutral correctly, while Rsimms has used the same word incorrectly. If it sounds weak and thin, it has tilted up high frequency response, and is therefore, NOT neutral.
However, this is not uncommon on these forums. In fact, I find that more folks use the term neutral to mean tilted up highs that highlight the treble region for the sake of detail, than use it to describe a natural sounding system which emphasizes neither the highs or the lows.