Audio Systems: No Sound Anymore, output impedence, infinity kappa

Question
I have a 92' Ford Tempo, which I replaced the factory HU with a Sony XR-CA330 and at the beginning I also replaced the back speakers with Infinity Kappa Reference series speakers.  Now the sound worked fine until I replaced the front speakers and put in a Inifinity Kappa 6.1 Perfect component system.  When I did this, the sound would goto the speakers, but if I tried to make it loud it would cut the sound from the speaker, but the HU would still continue to play.  So I went back and checked the wiring for any possible shorts or anything but couldn't find anything.  And now, I don't get any sound out of my speakers at all.  The HU has power, but no sound comes out of the speakers.  I was wondering what the problem could be.  Could it be the power going to the speakers or a defective HU? Thank you for your time.

Answer
Ryan,
The problem may be due to a defective audio amp inside the stereo unit possibly from the speakers being connected incorrectly or they were not of the correct impedence. A tip off is that when you turned up the sound the speakers would cut out. Check the output impedence of the stereo and the impedence rating(ohms) of the speakers.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net