I play as principle bass. When I imagine the same situation in my section, here is what I suggest you do.
A good and confident principle will welcome your input. He will consider what you say - you are after all a group, a team, and you're presumably a good bass player in his opinion so he should value what you have to say.
It's about time someone mentioned this. Thanks Witjas.
It is indeed sad that this thread has gone on as long as it has without someone pointing out that a principal should be
good and
confident enough that he/she can be
approachable by a respected colleague. This is a failure on the the principal's part.
And also, the section player should play so well that the principal cannot help but be receptive to a section player's opinion. If a section player is just a "talker," than that section player should just STFU.
In conclusion, to the OP, the conditions for workplace communication about musical ideas include: 1 ) the principal should be approachable and usually that stems from principals who are good and confident, and thus respected by the orchestra, the section, and the conductor. It should be no problem to approach the principal directly if this is the case. 2) The section player contributes with their playing on a day-to-day basis. This includes nailing the part, blending in, providing sufficient dynamic contrast, no spacing off with entrances, and most importantly, a subtle artistry that elevates the playing of everyone around him/her without opening one's mouth. If this is you, then the principal will have no problem hearing your opinion.
To the OP, if it is apparent that both of the above conditions cannot be satisfied, then just keep your mouth shut, and let the conductor take care of it.