There may be more going on than just the recording. Some equipment, mostly speakers, do not produce dynamics in a linear fashion to the input level, so that the speaker may not respond in the same proportion to a small signal at a given frequency than 1), it may respond to a larger signal at the same frequency or 2), and more commonly, at another frequency. For instance, if a speaker is voiced to boom and sizzle, the mids may be recessed making a solo harder to hear but when the orchestra kicks in the high and low frequencies overwhelm. The better the speakers, the easier to hear through the entire performance at various volume levels even when the overall dynamics actually improve. Heres a review that touches on this point. Just one more thing that makes this hobby so fascinating.
http://www.sonoris.co.kr/review/reviews/tas/exoticaGR_part1.pdf