You're right about needing a reference. I distinctly remember a lonely oboe in one recording though and it was just wafting and begging me to turn it up \:\) . I'm pretty sure that was pianissimo so I put myself out of my misery and just cranked it. Of course a few seconds later, a crescendo came along and my heart skipped a few beats \:\) .

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated