I have a 4 channel RF amp powering my coaxles in the front. from time to time, i notice that they sound like crap. it sounds like the tweets get shot up or something. this usually happens when the weather is hot and stuff. but then, it totally sounds clear and super nice when in the morning. could it be cuz my amp? or could it be cuz of my stupid RCA wires? i bought these cheap RCA's from the flea market. they're no name. and plus, the crossover on the amp is on high anyway. any help is appreciated.