Heresys are prone to 'shouting', and are very input (amp type... Macs are a good match) and room-placement sensitive (in my experience). So...
1) Make sure the XO connections are tight and correct (and that the woofers are working), and that the polarity of your speaker leads are correct,
2) Experiment with placement: near walls, away from walls, in corners, away from corners, on the floor, or risers, tilted up, etc.,
3) Refresh the caps in the XO (no need for new XOs). In my experience with heritage Klipsch 3-ways, the old caps tend to mute the highs, but it depends on where they drift.
Good luck!
...and congratulations! I'd love a pair of raw birch Decorators someday.