I thought I would start a new thread on this subject because I have heard a lot of demos lately in which the volume knob is used instead of the correct samples to represent an instrument playing at loud or soft levels.
Using a trumpet as my example, what I mean is that I have heard many cases in which people are using the volume knob to turn down its loudness in softer passages, when they should actually be using samples of softer playing in those parts. There is quite an audible difference between the two, because a trumpet player's attack on normal-to-loud notes is quite different from the attack used in playing softer notes, and it's easy to tell when the volume knob has been used instead.
For those who seek more realism in their recordings, this is a very important point that many seem to be overlooking. The volume knob is not a substitute for softer attacks (or louder, as the case may be). As in the example I gave, I have heard a number of cases where one trumpet level is used for all the passages in the piece, whether soft or loud, and it sounds very artificial when the volume knob is used to adjust the loudness. Volume is not the only consideration, especially for brass and woodwind instruments. The hardness and softness of the attack is just as important, if not more so, when striving for realism.
I hope others will add their comments here to elaborate, perhaps, in words that are better than my clumsy attempt at this. Please help me to get this point across.