I have a Kenwood KDC-X791 CD receiver with JBL amp and MTX sub....the other day I was driving and the stereo cut out...lost power and then came back on....I turned the sub off when it happend and then back on....the sub worked but then the radio shut off again and then the sub does not work now....I recently had infinity 6-1/2" installed in the front....checked the connections to the amp and everything is fine....any ideas please????????????

sounds to me like somebody didn't do a good job on your wiring. More than likely you have a faulty/intermittent ground somewhere. I would take it back to where you had the 6 1/2"s installed and see if they can trace out the problem. Tell them that the problem started after the install and they should do it for free. Otherwise, they'll probably just charge you a small fee.