Just installed a new car stereo, it turns on and functions, but no sound. Help?

I have a 2003 Mitsubishi Eclipse Spyder GTS. I just replaced the factory stereo with a new aftermarket stereo, a Kenwood KDC-HD545U. All the wires are connected properly for the speakers but there's still no sound. I can't take the silence so why is there no sound and how do I fix it?