Wow!!. Just installed a planet audio amp in my car. Sounds clean, amazing. THere is no hiss when I adjust the crossovers on the amp like my cheap amps. amazing sound. Five year warranty!!! I'm loving it. I thank you all that gave me the advice to go with planet audio amps. I got it for a decent price, sounds good, long warranty. I do have one question. It's probably a stupid question, but what is the 0 degrees to 180 degrees phase for? All my other amps were too cheap to have this feature I guess.