mastering software for mac

[bryantm3]

does anyone know of any free mastering software for mac? (excluding audacity)

i need to do some basic limiting and i would also like some tips for limiting without really limiting. for instance, i have transferred a few songs over from records and occasionally the volume will spike to the full 1 dB limit for a millisecond or so, and i would like to know how to level those out with the rest of the music without damaging the dynamics of the music in general.

thanks!

dan