Why do all my photos print so dark even with professional print labs

How do I set up Colorsync on my MacBook Pro? As my photos all print dark even when I use professional print labs. I use Aperture and Photoshop to edit RAW images from my Canon 5D and they look great on my Macbook. But I'm always so dissapointed with my dull prints which appear so underexposed. It's the same from my Epson Stylus SX525WD home printer or profesional print service labs.