My Tuba+Piano engravings: during midi playback, the Piano dominates the Tuba; why?

[Kenneth Wolcott]

Hi;

  My Tuba+Piano engravings: during midi playback, the Piano dominates
the Tuba; why?

  I know that this is really a midi versus live performance question...

  I can change the dynamics of the Tuba to be "fff" and both the left
hand and right hand of the Piano to be "ppp", and yet the Piano
dominates the Tuba during midi playback.

  I'm not expecting a midi playback to sound as good as a live
performance, but this seems...odd.

  Is there anything I can do with Lilypond to generate a midi playback
of Tuba+Piano pieces that sound more realistic?

Thanks,
Ken Wolcott